24
апр
1000 Hz Test Tone
Posted:adminOct 24, 2011 10 mins of 1000 hz for tuning. Manifest Love & Relationships Healing, Law Of Attraction Enhance Love Energy, 639Hz Meditation Music SUPERNATURAL BRAINWAVE POWER 713 watching Live now.
I've been tinkering with electronics ever since I was a kid - starting with taking apart and putting back together televisions and radios. I always got them back together again and working. I took courses in radio and electronics as a teenager, and became a ham radio operator. I worked in my high school's stage crew, running sound, lights, and a movie projector. After college, I joined a rock 'n roll band as the soundman and learned how to lug around and operate the gear that helps make music sound good and loud.Working in a music store in Austin, Texas, I spent a few years manufacturing, installing, repairing, and operating sound systems.
Our customers were recording studios, nightclubs, and touring bands. Eventually I moved back to Charlottesville, Virginia and opened a small demo recording studio. In 2006, I finally came to my senses and got this job at Crutchfield. They actually pay me to ramble on, rant, and explain the things I love about music, electronics, and getting good sound.Given my background, they put me to work writing about some of the most complex electronic products Crutchfield sells: car amplifiers, digital signal processors, wiring, professional sound mixers, and PA systems. Buck in the Crutchfield LabsIn an amplified car system, you need to set your amplifier’s gain correctly in order to enjoy your music’s full range of dynamics and frequency response — hearing all the notes clearly, whether loud or soft. You’ll feel your music’s impact better and hear exciting details that otherwise would get lost in your car.There're quite a few ways to set gain, but I think listening to test tones is the simplest method giving the best results. Continue reading the article if you want to see how I came to this conclusion by my researching the isssue in the Crutchfield Labs.
Instructions for setting amp gain using test tones. Download 0 dB sine wave test tones of 40, 100, 400, 800, and 1000 Hz to your preferred medium (disc, chip, file, phone). Set your receiver’s EQ presets and the amp’s bass boost to the way you normally listen to your music. With the amp gain at minimum, play the 40 Hz tone and turn up the receiver’s volume until you hear it buzz. An example of a a clean waveform (left) and a distorted, clipped wave (right) 2. Test tones and speakersBut seeing as most people don’t have oscilloscopes, I thought that maybe by listening to the tones through speakers, one could also set an amplifier’s gain correctly. A non-distorted sine wave test tone sounds like a pure hum.
When it distorts, you can clearly hear it buzz. By using test tones played through a speaker, I wondered how accurately I could set an amp’s gain as compared to setting it by the other methods. A deep dive into my Crutchfield Labs projectI went into The Crutchfield Labs and set up an amplifier, wired to a power supply, a car receiver, and a pair of speakers. I also attached two sets of probes to a pair of speaker wires, one going to a voltage meter and the other to an oscilloscope. This way, we could see what the sounds look like and read the resulting power level the amp produced.
Pioneer DEH-3400UB First set the tone controls to the way you listenThe receiver's and amp’s EQ and crossovers needed to be set to where they normally would be when playing music. This is so the gain would be set under real-world conditions.
Adding boost, at any frequency, after setting the gain, can make the amp clip, distorting the sound and endangering speakers and subs.I let the receiver (a Pioneer DEH-3400UB) stay in its factory preset “Dynamic” EQ setting, which boosts the bass and treble for a fuller sound. That meant certain frequencies would play louder than others. I needed to find out which tone clipped the receiver first, at the lowest volume setting. Then, I needed to use that receiver volume setting at that tone’s frequency to set the amp’s gain. Part 1: Setting the gain with the oscilloscope How loud can the receiver play and still play clean?I started with the amp’s gain set to its minimum, and the speakers disconnected. I played the first tone, 40 Hz, a low bass note, only fit for subwoofers, and set the scope to view the sine wave. Then I turned up the receiver’s volume until I could see something bizarre happening to the wave’s shape. It didn’t “clip” at the top and bottom, it distorted in the middle.
But I could see exactly at what volume level the distortion first appeared, and where it disappeared.I took note of what the receiver’s volume reading was: 52. (The receiver’s top volume number was 62.) That meant the receiver played 40 Hz clean and at its loudest at its “52” volume. Test Tone CD Track 740 HzMaximum Clean Volume = 52Test Tone CD Track 8100 HzMaximum Clean Volume = 51Test Tone CD Track 9400 HzMaximum Clean Volume = 57Test Tone CD Track 101K HzMaximum Clean Volume = 59Test Tone CD Track 114K HzMaximum Clean Volume = 56Test Tone CD Track 128K HzMaximum Clean Volume = 55This receiver plays loudest at volume 51, otherwise 100 Hz notes would clipI measured the receiver’s distortion-free top volumes for the other test tones on the disc. The 100 Hz tone stood out as the strongest — I had to turn the volume to its lowest setting to get it to play clean. Because that volume represented the level that all the tones would play cleanly through the receiver, I used the 51 setting for the receiver’s volume for the next step. Because the 100 Hz tone was the strongest, and would clip the amp first, I used the 100 Hz test tone to set the amp's gain.
Sound Ordnance M-4050 The amplifier’s turnI played the tone and looked at the sine wave while turning up the amplifier’s gain knob. Any waveform distortion I then saw came from the amp, not the receiver. Turning the gain back down until the distortion disappeared, I set the gain exactly where the amp and receiver were both at their maximum clean output levels: perfectly gain-matched. Setting the gain right optimizes the amp’s outputI turned up the gain to the amp’s top clean-playing point and read the volt meter. The volt meter read AC (alternating current) voltage, and the amp I used (a Sound Ordnance M-4050 4-channel) showed a top clean output for 100 Hz of 17.6 VAC.
That translated to about 77 watts. Not bad for an amp rated at 50 watts RMS per channel. Bench testing results in higher power readingsWhat was going on was the power supply the receiver and amp used was 13.5 volts DC, about the same as a running car’s system usually provides, but the amp wasn't connected to the speakers and so wasn't loading down the power supply with the increased current demand of the speakers. That explained some of the “extra” power. But the amp definitely performed above its specified rating.
If I had wanted to, I could have set the amp’s output to exactly 50 watts, by turning the gain down until the voltage read a targeted number, in this case 14.14 volts AC. Math formulas — skip this paragraphThe wattage equals the voltage squared divided by the speaker’s impedance in ohms, 4 ohms in most cases. The voltage equals the square-root of the product of the wattage times the speaker’s impedance (also usually 4). 50 watts times 4 ohms equals 200; the square-root of which is 14.14 volts AC. 14.14 volts through 4 ohms of impedance creates 50 watts of power.
These formulae are based on Ohm’s and Joule’s Laws and you can’t break them if you tried. A note on multimeter accuracyTo accurately measure your amplifier’s output power with a multimeter, use a 60 Hz tone for a subwoofer amp, and a 100 Hz tone for a full-range amp with its high-pass filter turned off. This is because most meters are made to measure AC voltage accurately at 50-60 Hz (the common frequency of all power systems around the world). Using a standard hand-held multimeter to measure the voltage of a higher-frequency signal results in readings that are much lower and leads to inaccurate power calculations. For instance, the Amprobe 15XP-B multimeter I used in this Labs demonstration reads the voltage of a 0 dB 1 KHz signal about one-fifth the level that it reads at 40 Hz or 100 Hz.
This would result in a calculated wattage about one-twentieth of the correct output power. Different meters will have different degrees of deviation. Kenwood KFC-6984PS Part 2: Setting the gain using speakers and my ears The noisy part of the testI then repeated the whole performance with one speaker connected — a Kenwood KFC-6984PS 6'x9' 4-way. I want to say, in advance, that this was not a pleasant experience. Two hours later, my ears were still painfully ringing from the very high 8K Hz tone. Jordan, also in the Labs area at the time, complained that the 4K Hz tone was still ringing in his.
This method can produce high-pitched, annoying, ear-drilling sounds that could hurt your hearing if you expose yourself for too long, and definitely will bother everyone within listening distance.For using tones and your ears to set an amp’s gain, I recommend sticking with only the 40, 100, 400, or 1K Hz tones. They don't hurt at all. The 100 Hz tone alone will do for both subwoofer and full-range speaker amps. When a hum starts to buzzA sine wave sounds like a hum.
When it distorts, you can clearly hear it buzz. Again, the 100 Hz tone was the first to buzz, and at the exact same 51 volume setting. With the receiver at that top distortion-free level, I played the tone again and turned up the amp’s gain until I could hear the tone buzz again. Then I backed it off until the hum alone remained. The place the gain knob was set and the voltage readings were exactly the same as it had been using the scope.I did this test after working hours so no one else would be disturbed.
But I proved to myself, at least, that the ear-and-tone method worked just as well and as accurately as using a scope. The 40 Hz tone couldn't really be reproduced by the speakers, so was useless. The 100 Hz tone rattled everything on the desk, so it was a little difficult to pick the buzz-point out of the crowd of reverberations. The 400 Hz tone was the best tone to detect clip-points, with a very clearly defined hum-to-buzz point. I hear musicFinally, I tried music and my ears alone.
I performed this test twice, days apart, and also afterhours. Not everyone wants to hear my songs played loudly over and over again. At first, I played a favorite R&B-type song full of percussion, bass, horns, and lots of production — but I couldn’t hear it distort, only get loud. So I switched to a clear-voiced female vocalist singing swing. I also played a male singer, to see if it would be any different — it wasn’t. Your hearing gets more acute when you close your eyesI closed my eyes when I did this test, so no numbers were used to set the receiver’s top volume.
I turned it up until I heard something go wrong with the vocal — it seemed thinner, not as bell-like, and harsher. The male singer's voice suddenly developed a rasp. After turning the receiver down a little, restoring the fine quality of the singer’s voice, I turned up the amp gain until I heard the same thing.The two times I did this test, I got two different results. The first time, the receiver's maximum volume setting ended up one notch below the tones and scope setting. The second time, it was one notch higher than the tones and scope setting.
But both times, the amp gain setting was exactly the same as the other methods. The differences can’t be heardOn the first day, setting it by ear and music alone, I ended up thinking I should never turn the receiver higher than 50, and the gain was set so that at that 50 volume, the amp put out 15.7 VAC at 100 Hz, or 62 watts. On the second day, it ended up that I could turn it up to 52, and get 18.8 VAC at 100 Hz, or 88 watts. That 100 Hz tone was indeed slightly distorted visually, but it wasn't audible in the music.
Plus, I don't usually listen to music full-blast for very long periods of time, so in real use, I would likely never be able to hear the difference. It’s all about the musicI think either I was a little more or less sensitive to the singers’ voices on different days, and noticed changes at different levels than I could see in the waveforms’ shapes, or the music CDs I used were recorded at a different reference levels.
I certainly cranked some swing those evenings in the Crutchfield Lab.Whatever the differences between the methods were, they all resulted in having the receiver and amp properly gain-matched, and loud, distortion-free music ensued. Using the test tones disc was easier than listening to music. Even without the oscilloscope, the tones made it possible for me accurately set the gain. It was very easy to discern when the hum distorted into a buzz.Download some test tone files or pick up a test tone disc and try if for yourself!
Ryan from New YorkPosted on 2/5/2019I have a pioneer headunit and a mosconi amp, with these two level matching using DMM and test tones are a breeze, now I have changed to a JVC headunit with the same voltage preout, but the readings are way low using the same amp. With the pioneer I can get 25v from the amp easy, with the JVC it can barely reach 6v, tried a new JVC 2-din with same preout voltage, same result barely 6v output. Am I missing something?
Why with the pioneer I can get correct output and not with the 2 new JVC? Nathan Vetter from East AuroraPosted on Buck, could you lend some advice my way?i installed Infinity Reference 6532ix's (coaxial) in the rear door of my 2016 Chevy truck and Infinity Reference 9630cx's (components with passivize crossovers) in the front. I am also running a kicker key 180.4 amp to power these. I followed your o-scope method to the tee.
I played test tones from my phone over the Bluetooth connection and with my phone volume all the way up. I found my limiting Hz and volume level. I let the amp run it's auto tune with the gains all the way down and again using a pink noise tone over bluetooth from my phone.
After the auto tune finished i try to set my gians. For some reason the front channels (or amp #1 on the key) clip 1kHz with the gian all the way down. But the rears do not.
I can set the rear gains to about half way on their rotation. The resulting in cab sound is so rear heavy i cant help to think i am doing something wrong.i tried to re-do the entire process with the volume level output on my phone at the 'normal' level (about 3/4 on its scale and where the phone automatically sets it when first connecting to a Bluetooth device). I was able to get some more range with the gains but when you switch from the Bluetooth single to a radio the volume of the radio blows you away. This cant be right either. What am i doing wrong? Buck Pomerantz from Crutchfieldon Nathan, It is my understanding that if you use the Auto Setup process for your Key 180.4, you leave the amp gain at minimum and the program automatically sets gain, balance, fade, time-alignment, high-pass filters, and EQ optimized for the front seat position or wherever you put the Setup mic. When you change settings on the amp after setup, you're undoing all the good tuning the amp automatically made.
Set the gain and filters of your amp with either the method outlined in this article, or by the Auto Setup process, but not both. Whites from PhiladelphiaPosted on 12/7/2018If you think it's the speakers than that's pretty disappointing - especially at $400 a pair. Do you have any experience with these speakers (Morel Tempo Ultra Components)?
However, unwinding has become big business, and there are powerful political and corporate interests that want to see it not only continue, but also expand to the unwinding of prisoners and the impoverished.Cam is a product of unwinding; made entirely out of the parts of other unwinds, he is a teen who does not technically exist. A futuristic Frankenstein, Cam struggles with a search for identity and meaning and wonders if a rewound being can have a soul. Ridding society of troublesome teens while simltaneously providing much-needed tissues for transplant might be convenient, but its morality has finally been brought into question. Rife with action and suspense, this riveting companion to the perennially popular Unwind challenges assumptions about where life begins and ends-and what it means to live.Thanks to Connor, Lev, and Risa-and their high-profile revolt at Happy Jack Harvest Camp-people can no longer turn a blind eye to unwinding. Unwholly pdf.
I bought them from Crutchfield. If they can't perform as well as others I might be swapping these for something else. How long is Crutchfield's return policy?Are other 5 1/4' speakers able to reproduce 80hz -3db sine waves without distorting at 35% HU volume? Care to recommend any?Thanks Buck!Morel T. Whites from PhiladelphiaPosted on 12/3/2018Great read - Thank you for the info!I tried using the 'test tones by ear' method in my setup however, and didn't get very far.
In trying to find the maximum HU volume, my full-range components (Morel Tempo Ultra 5 1/4') began buzzing at a much lower HU volume than normal everyday listening volume - I'm talking normal person listening volume. Not 'car audio enthusiast' volume haha. Using -3db sine waves in the 60- 100hz range, my woofers began buzzing at approx 35% HU volume. Surely these speakers should be able to take about 35% of HU volume with no eq boosts and the amp gains turned down. In addition, I also have my HU's HPF set to 80hz with an -18db cutoff slope so they aren't even running 'full range'.So what gives? Why would I be getting a distortion buzz at such low HU volume?
Are sine wave test tones in the 60-100hz range not appropriate for testing full range speakers using the 'test tones by ear' method? Logically it seems appropriate since theres lots of activity going on in that frequency range, normally played at higher levels than 35% HU volume. Any insight would be greatly appreciated.The equipment chain in question is.HU - Pioneer AVH-1440NEX (No 'Bass Boost' or eq boosts - HPF @80hz w/ -18db Cutoff slope)Amp - Alpine PDR-V75 (gains set low - no 'Bass boost' or HPF applied)Speakers - Morel Tempo Ultra 5 1/4' ComponentsThank you for your time and for sharing your knowledge! Brandon from CharlestonPosted on 7/31/2018After further testing, I've discovered it's only the right midrange woofer making the noise, but the strange part is that I'm not sure it's distortion. It almost sounds like a faint telephone beep tone.
I swapped that speaker's wires to the left crossover, which is run by channel one, to rule that out. The issue persisted.
I disconnected all other speakers to make sure it wasn't a polarity issue, but issue persisted. Played the left driver and the tone was gone. What the heck is going on? Maybe that one speaker wire is picking up noise somewhere in the car?
Seems strange since both channel's wire is run side by side on the passenger side. Butch from Montgomery Vlg MDPosted on 7/5/2018Thank you for your response, Buck. I will try the 100Hz tone (maybe the others too) for both the 4channel Pioneer GM 8604 and the SSL LoPro10 sub. I don't detect distortion from my camry 2016 head unit even at full blast (with amp turned down) so I tune at 75% volume.
Maybe using your method, I will finally get the best of my PolkDB6502s and my 70RMS rear 6x9 kickers. My problem is that I want it to sound as clear and clean as my home sound system, which is really impossible. I really appreciate the clear response (perhaps dumbed-down for me, thank goodness) and the informative article. Sincerely appreciated. Buck Pomerantz from Crutchfieldon 6/29/2018 Butch, I think you're referring to an amp gain setting technique that uses a volt meter to attain a target output voltage that matches the desired output wattage.
I do not recommend that way of setting gain because it doesn't take into account whether or not the source is clipping, nor the accuracy of the meter at any frequency besides 60 Hz. Playing a distorting tone loudly might eventually damage a speaker, but not for the short time needed to set an amp's gain. Matthew from PensacolaPosted on 5/16/2018Nice article but for some reason, every single article I've read regarding amp tuning, ( I've read dozens of them from many different websites) every single one leaves out a key factor and I can't for the life of me figure out why it gets left out or why no one ever seems to ask. Maybe it's just me I'm not sure, very well could be. My question is, where do you set the crossover on the amp when setting gains since every single person who makes a tutorial neglects to mention it. Perhaps it isn't important at all whatsoever since it's never mentioned.
Perhaps it's an industry secret that isn't suppose to be talked about to those who don't already know about it. Think Fight Club. Regardless, can someone please please pretty please tell me once and for all what I'm suppose to do with the crossover on my amp when playing test tones to set my gains. I promise to never speak of it to anyone ever. I will guard the secret with my life I swear. Plz and thank you.
Buck Pomerantz from CrutchfieldPosted on 3/9/2018John, Multimeters read RMS voltage. So attaining an output of 30 volts RMS through a 2-ohm load produces 450 watts RMS.
You can measure the signal's peak-to-peak voltage with your scope, as well as see when it clips. The only harm you can do to a sub by playing a 50 Hz tone is if you play it too loud.
If your amplifier is rated higher than your sub, setting gain with an oscilloscope won't work - the sub's sound will distort before the amplified waveform shows any distortion at all. JohnPosted on 3/8/2018When setting the gain of my amp I'm targeting 30Vp-p for a 450W output on my 2ohm sub. The gain setting for my amp to get 30V on my multimeter gives me about 80V on my scope.This must be due to the low input impedance of the scope giving unrealistic output from the amp. I don't have a dummy 2 ohm load rated for that kind of power.
Is it okay to play a 50 Hz test tone on my actual sub or will I damage it? I figure a reading with the scope under the actual load is the best way to optimize the power output of the amp.My amp rating is higher than my sub so I want to push it as much as I can without damage. Clipping doesn't seem to be a problem for me.Thanks!John. Buck Pomerantz from CrutchfieldPosted on 2/2/2018Brian, The spikes you see are probably more an artifice of your oscilloscope's response-time than the clipped signal's harmonic radiation.
Clipped signals, as you noticed, don't always take the form of a square wave. What you're also witnessing is the fact that your gear clips different frequencies at different levels. Find out which frequency at which the receiver first clips and use that frequency tone to set your amp gains. For example, if your receiver clips 4k Hz at a lower volume setting than any other signal, you'd use that tone to set amp gains. Also, the amp gains should be re-set after any EQ or tone adjustments are applied. From HoustonPosted on 2/1/2018So I've been messing around with my oscilloscope to set the gains on two amps. My head unit is a pioneer AVH X2800bs4 channel pioneer GM D8604JL Audio j2 500.1 monoblockWhen I isolate the head unit I'm checking the max output through the rca cables with a 0dB test tone suite I made.
Once I found the max receiver volume at 0dB I disconnected all speakers and plugged the rca pre-amps back in. What is interesting to me is the 4channel amp when playing a test tone at max unclipped rca output does not form a square wave but starts to spike in the center with what looks like harmonic destabilizing centered around the wave peak which if gain is further increases shows the expected flat top however it still contains a sharp spike at the start and end of the square peak. Could this just be an artifact of class d amplifiers?Also when I set 1kHz to max unclipped amplification then check 4kHz and 8Khz the higher frequencies show 'sine like' waveforms but the shape is somewhat distorted.
And even when maxed out on the gain the 4-8kHz don't show up as a flat topped wave but rapidly spike the voltage and appear completely garbled.So to much question. Should I be setting the gain based on the 1kHz signal or let the higher frequencies set the ceiling?. Dann Combs from Colorado Springs, COPosted on 11/2/2017Thanks Buck.
I've read versions of these approaches at least two dozen times in my quest to educate myself but yours is the most clear and concise. Well written.
I do have one question though.How do I incorporate remote level control on the amp (SoundStream PN1.650D) in this process? This amp has a gain control, a bass boost control, and an external remote level control.
I am not going to use the 45 Hz bass boost and will just leave that dialed all the way down to minimum. I have an oscilloscope and understand the process. Tl wn851n drivers for mac.
But I've seen no advice regarding the remote control. Is that simply another gain control knob? Or is it in some way different from the gain control dial on the amp? If it's just another gain control then my inclination is to set it to the max and leave it there, setting the on amp dial to minimum and turning the on amp dial up until I find clipping, backing it off to the clean signal point and leave it there permanently.
Then, while playing music I could use the remote knob to turn down the bass to desired levels, knowing that I could not worry about turning it up to max if desired. Is that the right approach? Or what is recommended for working with both the gain dial and the remote knob in the gain setting process?Thanks again. Glennon heinrich from macedonPosted on 9/26/2017Okay so I've been running 2 Infinity Kappa 100.9 W's in a sealed box with passive radiators tune to 27 Hertz and it sounds phenomenal at 600 RMS each even though they're rated for like 375. I've since switched the speakers to 4 ohm to introduce a 2 ohm load and then I wired in a 12 inch earthquake dbxi in parallel to bring it back to a 1 ohm load. And now it doesn't sound nearly as good but an R&B it's definitely louder and shakes everything more.
Could that be because the 12 is in a sealed box would it sound better if I get that box tuned to the same frequency as the other. In the pr enclosure those subs take 600 watts RMS all the way down to 12 Hertz then you start to get mechanical noise I've only done it once lol. Brian from Bay AreaPosted on 9/7/2017Hey Buck, fantastic article! I can wait to try all this stuff out next week.Couple things:When you're determining your HU's max clean volume, your gains at that point are at the minimum, right? If you were to have the gain somewhere else but still on the lower end, (say 10% or 20%), would the distortion point on the HU vary in any way?Also, if I want to leave some room to play with for my subs, I'm assuming I should set the HU's sub control to its max or at least whatever number I want to use as my max when setting the gain, correct?And lastly, which is better? Running two 500 RMS subs at 4 Ohms with an amp that puts out a max of 1100 at 4 Ohms, or the same two subs at 2 Ohms where the same amp puts out 2000 at 2 Ohms? Is the amp working harder in the first scenario vs the second?Thanks!.
Buck Pomerantz from CrutchfieldPosted on 5/3/2017Cody, The misuse of low-pas filters (HPF) and bass boosts lead to the destruction of many subwoofers. Both are equalizers used to optimize the tone of the bass sound.
A low-pass filter gets engaged to remove the high-frequency notes you don't want the sub to play. Turning it 'all the way up' is not the proper way to set it.
Check out for that. A bass boost gets engaged when you want to emphasize the lowest bass notes, around the low E of a bass guitar or piano. If you like the tone when using a bass boost, you must readjust the amp's gain control to compensate for the boost in over-all volume and ensure that no dangerous distortion ever plays.
Achieving full power in an amplifier depends on setting the gain correctly, not on the tone of the bass signal. Cody from Scott AFBPosted on 5/2/2017Sir/Ma'am,So I have an Orion Step to 122d 12' sub rated 1500 RMS and an Orion amp 1500 RMS and i fried a sub after it was professuonally tuned.So basically to tune properly the LPF needs to be all the way up along with the volume at the proper level then adjust the gain till it clips/distorts/buzzes right?So what's the purpose of having bass boost? Basically I want to push all 1500 RMS or close to it but not sure you could do that without bass boost.Also, I have a yellow top batt ran to my primary and my amp ran to the yellow top so it has a standalone battery all for itself. Cory from long beachPosted on 2/14/2017I have read some tutorials stating that you should only use the scope and test tone to set the gain up to the voltage calculated by the units actual power and the 4 ohms, and not the clipping point. The difference being that the former is the manufacturers recommended limit for 'stable' power, and though there may be headroom between that number and the clipping point (your extra found power), it was not necessarily stable there.
Do you have any insight on that?. Buck Pomerantz from CrutchfieldPosted on 9/19/2016Tendai, The gremlin's in your multi-meter - it's only accurate at 60 Hz.
And you didn't say what the impedance of your subs are. 20 volts AC through a 2-ohm sub, for instance, generates 200 watts RMS. Another complication that you might not be aware of is that the impedance of a speaker or sub changes with different frequencies, and its output power does as well. Trying to set amp gain using an inaccurate meter reading the voltage of different frequencies through an unknown impedance will not work very well.
If you have an oscilloscope, use that to set your amp gains, it will result in a more accurate setting. Tendai from DerbyPosted on 9/19/2016Hi again BuckThanks for that. I'd purchased a DSO 112 O'scope which was en route when I asked. I've since hooked it up to the amp and set the gain using 1000Hz tone for the mids and 40/50 tones for the 8 inch woofers cutting the gain to about 10% before clipping.That said I then went on to check the output voltages after all had been set with lovely sine waves on the scope. Strangely channels 1 and 2 show voltages of 17.5 and 16.5 even though I set them both to high pass at the same level (180 as per mfr).Stranger still channels 3 and 4 which are for the woofers low passed at (100Hz as per Mosconi) show voltages of 20-21 without any sign of distortion.Is there a family of gremlins in the amp?.
Tendai from Derby, UKPosted on 9/10/2016Hi BuckGreat article. Still a bit confused.
I have a Mosconi 130.4 DSP amp rated at 130RMS per channel at 4 ohms or 175RMS at 2 ohms. My speakers are Gladen 201 3 way with 4x150/100 rating at 3 ohms in a BMW E60 UK spec with 2 channels being 8 inch subs and 2 channels feeding doorcard midbases plus tweeters via a crossover. I take the 100 to be the nominal rating in that? What target voltage would you recommend if I were to use a DMM? I've tried setting by ear but the E60 BMW does not have a visual for the volume so it's difficult to tell when one has hit 3/4 volume etc etc plus the buttons can be pressed til time immemorial without one having the foggiest whether you've hit the top, mid-top, somewhere-top, not-so-top etc. Buck Pomerantz from CrutchfieldPosted on 8/2/2016Kenyon, Test tones and oscilloscopes are commonly used to set gains in audio equipment - a device's input sensitivity to the output of a preceding device in a system.
You can download '0-dB' test tones for free from the internet - a web search will turn up a vast selection. After downloading, you can burn them to a CD or store them onto a thumb drive for playing later. You then use the oscilloscope to visualize the tone as a sine wave - when the sine wave distorts, it means the signal's clipping and the gain needs to be reduced. I can't think of any reason to use test tones and an oscilloscope to set an equalizer or a crossover, however. For those, people often use pink noise and an RTA (real-time analyzer).
Buck Pomerantz from CrutchfieldPosted on 4/8/2016Zack, A subwoofer voice coil presents an inductive load, not a resistive load, to an amplifier's output - so measuring a coil's DC resistance with a multimeter won't accurately tell you its impedance. A coil's impedance actually changes according to the frequency of the signal played. Using the manufacturer's 'nominal' impedance rating will bring the best results. Just be sure, when setting the gain, that your source is at its highest level with no clipping and your multimeter is accurate at the frequency of the tone you use. Most meters only read accurate AC RMS voltage around 60 Hz.
(PS: producing 300 watts through a 2-ohm load takes 24.5 volts.). Zack from EulessPosted on 4/8/2016I plan on setting my gain using a multimeter and calculating the max volts I should see for my sub. The reason is that I have a 12' DVC sub wired in parallel that can handle 300 watts RMS, but the Alpine amp powering it can put out 500 watts RMS in 2-ohm mode. So I need to calculate how many volts 300 watts RMS is, then set the gain to that level.In doing my math, should I first test the positive/negative speaker lead to the sub to get the exact ohms for my calculation? Or is just going with 2-ohms okay? I'm just concerned that different subs/speaker runs may introduce resistance variation, and I'm trying to be accurate.
Ken Lacy from BaxterPosted on 8/24/2015Please help? I have installed a Pyle 5 channel amp 6800 watts into a chevy cruze. Powering an alpine 12' sub rated for 1000 rms.
Power from Batt measures 14.2 at the amp. Ground is good from the amp to the frame. 17ft rca's from the stock head unit with a pac AAGM-44 adapter to give me the rca outputs. Everything is brand new. All settings on hu and amp set to minimum or 0 - volume at 75%. I play the 50hz sounds and my multimeter starts at 6 volts and i turn the gain all the way up and the highest voltage i get is 44. I have two other gain adjusters for the other 4 channels and the highest reading i get on either of them is 42.
My 2 ohm sub calls for 48 watts. Everything I read from others doing it, they can get the readings up over 60 watts and gain not even turned up all the way.Any ideas why I am getting less than normal wattage readings?.
The audio test tones below are available for free download and use in your projects. Select the tone you wish to download and click the corresponding format of your choice (or right-click and select 'Save link as..'). All files are mono, sampled at 44100Hz, 16-bit. If you're not sure which tone you want, 1kHz is a safe bet.
| Tone Frequency | Duration | Download: | |
| 100Hz | 0:05.00 | wav (0.4MB) | mp3 (0.1MB) |
| 0:30.00 | wav (2.5MB) | mp3 (0.5MB) | |
| 250Hz | 0:05.00 | wav (0.4MB) | mp3 (0.1MB) |
| 0:30.00 | wav (2.5MB) | mp3 (0.5MB) | |
| 440Hz | 0:05.00 | wav (0.4MB) | mp3 (0.1MB) |
| 0:30.00 | wav (2.5MB) | mp3 (0.5MB) | |
| 1kHz | 0:05.00 | wav (0.4MB) | mp3 (0.1MB) |
| 0:30.00 | wav (2.5MB) | mp3 (0.5MB) | |
| 10kHz | 0:05.00 | wav (0.4MB) | mp3 (0.1MB) |
| 0:30.00 | wav (2.5MB) | mp3 (0.5MB) | |
Popular Posts
Oct 24, 2011 10 mins of 1000 hz for tuning. Manifest Love & Relationships Healing, Law Of Attraction Enhance Love Energy, 639Hz Meditation Music SUPERNATURAL BRAINWAVE POWER 713 watching Live now.
I\'ve been tinkering with electronics ever since I was a kid - starting with taking apart and putting back together televisions and radios. I always got them back together again and working. I took courses in radio and electronics as a teenager, and became a ham radio operator. I worked in my high school\'s stage crew, running sound, lights, and a movie projector. After college, I joined a rock \'n roll band as the soundman and learned how to lug around and operate the gear that helps make music sound good and loud.Working in a music store in Austin, Texas, I spent a few years manufacturing, installing, repairing, and operating sound systems.
Our customers were recording studios, nightclubs, and touring bands. Eventually I moved back to Charlottesville, Virginia and opened a small demo recording studio. In 2006, I finally came to my senses and got this job at Crutchfield. They actually pay me to ramble on, rant, and explain the things I love about music, electronics, and getting good sound.Given my background, they put me to work writing about some of the most complex electronic products Crutchfield sells: car amplifiers, digital signal processors, wiring, professional sound mixers, and PA systems. Buck in the Crutchfield LabsIn an amplified car system, you need to set your amplifier’s gain correctly in order to enjoy your music’s full range of dynamics and frequency response — hearing all the notes clearly, whether loud or soft. You’ll feel your music’s impact better and hear exciting details that otherwise would get lost in your car.There\'re quite a few ways to set gain, but I think listening to test tones is the simplest method giving the best results. Continue reading the article if you want to see how I came to this conclusion by my researching the isssue in the Crutchfield Labs.
Instructions for setting amp gain using test tones. Download 0 dB sine wave test tones of 40, 100, 400, 800, and 1000 Hz to your preferred medium (disc, chip, file, phone). Set your receiver’s EQ presets and the amp’s bass boost to the way you normally listen to your music. With the amp gain at minimum, play the 40 Hz tone and turn up the receiver’s volume until you hear it buzz. An example of a a clean waveform (left) and a distorted, clipped wave (right) 2. Test tones and speakersBut seeing as most people don’t have oscilloscopes, I thought that maybe by listening to the tones through speakers, one could also set an amplifier’s gain correctly. A non-distorted sine wave test tone sounds like a pure hum.
When it distorts, you can clearly hear it buzz. By using test tones played through a speaker, I wondered how accurately I could set an amp’s gain as compared to setting it by the other methods. A deep dive into my Crutchfield Labs projectI went into The Crutchfield Labs and set up an amplifier, wired to a power supply, a car receiver, and a pair of speakers. I also attached two sets of probes to a pair of speaker wires, one going to a voltage meter and the other to an oscilloscope. This way, we could see what the sounds look like and read the resulting power level the amp produced.
Pioneer DEH-3400UB First set the tone controls to the way you listenThe receiver\'s and amp’s EQ and crossovers needed to be set to where they normally would be when playing music. This is so the gain would be set under real-world conditions.
Adding boost, at any frequency, after setting the gain, can make the amp clip, distorting the sound and endangering speakers and subs.I let the receiver (a Pioneer DEH-3400UB) stay in its factory preset “Dynamic” EQ setting, which boosts the bass and treble for a fuller sound. That meant certain frequencies would play louder than others. I needed to find out which tone clipped the receiver first, at the lowest volume setting. Then, I needed to use that receiver volume setting at that tone’s frequency to set the amp’s gain. Part 1: Setting the gain with the oscilloscope How loud can the receiver play and still play clean?I started with the amp’s gain set to its minimum, and the speakers disconnected. I played the first tone, 40 Hz, a low bass note, only fit for subwoofers, and set the scope to view the sine wave. Then I turned up the receiver’s volume until I could see something bizarre happening to the wave’s shape. It didn’t “clip” at the top and bottom, it distorted in the middle.
But I could see exactly at what volume level the distortion first appeared, and where it disappeared.I took note of what the receiver’s volume reading was: 52. (The receiver’s top volume number was 62.) That meant the receiver played 40 Hz clean and at its loudest at its “52” volume. Test Tone CD Track 740 HzMaximum Clean Volume = 52Test Tone CD Track 8100 HzMaximum Clean Volume = 51Test Tone CD Track 9400 HzMaximum Clean Volume = 57Test Tone CD Track 101K HzMaximum Clean Volume = 59Test Tone CD Track 114K HzMaximum Clean Volume = 56Test Tone CD Track 128K HzMaximum Clean Volume = 55This receiver plays loudest at volume 51, otherwise 100 Hz notes would clipI measured the receiver’s distortion-free top volumes for the other test tones on the disc. The 100 Hz tone stood out as the strongest — I had to turn the volume to its lowest setting to get it to play clean. Because that volume represented the level that all the tones would play cleanly through the receiver, I used the 51 setting for the receiver’s volume for the next step. Because the 100 Hz tone was the strongest, and would clip the amp first, I used the 100 Hz test tone to set the amp\'s gain.
Sound Ordnance M-4050 The amplifier’s turnI played the tone and looked at the sine wave while turning up the amplifier’s gain knob. Any waveform distortion I then saw came from the amp, not the receiver. Turning the gain back down until the distortion disappeared, I set the gain exactly where the amp and receiver were both at their maximum clean output levels: perfectly gain-matched. Setting the gain right optimizes the amp’s outputI turned up the gain to the amp’s top clean-playing point and read the volt meter. The volt meter read AC (alternating current) voltage, and the amp I used (a Sound Ordnance M-4050 4-channel) showed a top clean output for 100 Hz of 17.6 VAC.
That translated to about 77 watts. Not bad for an amp rated at 50 watts RMS per channel. Bench testing results in higher power readingsWhat was going on was the power supply the receiver and amp used was 13.5 volts DC, about the same as a running car’s system usually provides, but the amp wasn\'t connected to the speakers and so wasn\'t loading down the power supply with the increased current demand of the speakers. That explained some of the “extra” power. But the amp definitely performed above its specified rating.
If I had wanted to, I could have set the amp’s output to exactly 50 watts, by turning the gain down until the voltage read a targeted number, in this case 14.14 volts AC. Math formulas — skip this paragraphThe wattage equals the voltage squared divided by the speaker’s impedance in ohms, 4 ohms in most cases. The voltage equals the square-root of the product of the wattage times the speaker’s impedance (also usually 4). 50 watts times 4 ohms equals 200; the square-root of which is 14.14 volts AC. 14.14 volts through 4 ohms of impedance creates 50 watts of power.
These formulae are based on Ohm’s and Joule’s Laws and you can’t break them if you tried. A note on multimeter accuracyTo accurately measure your amplifier’s output power with a multimeter, use a 60 Hz tone for a subwoofer amp, and a 100 Hz tone for a full-range amp with its high-pass filter turned off. This is because most meters are made to measure AC voltage accurately at 50-60 Hz (the common frequency of all power systems around the world). Using a standard hand-held multimeter to measure the voltage of a higher-frequency signal results in readings that are much lower and leads to inaccurate power calculations. For instance, the Amprobe 15XP-B multimeter I used in this Labs demonstration reads the voltage of a 0 dB 1 KHz signal about one-fifth the level that it reads at 40 Hz or 100 Hz.
This would result in a calculated wattage about one-twentieth of the correct output power. Different meters will have different degrees of deviation. Kenwood KFC-6984PS Part 2: Setting the gain using speakers and my ears The noisy part of the testI then repeated the whole performance with one speaker connected — a Kenwood KFC-6984PS 6\'x9\' 4-way. I want to say, in advance, that this was not a pleasant experience. Two hours later, my ears were still painfully ringing from the very high 8K Hz tone. Jordan, also in the Labs area at the time, complained that the 4K Hz tone was still ringing in his.
This method can produce high-pitched, annoying, ear-drilling sounds that could hurt your hearing if you expose yourself for too long, and definitely will bother everyone within listening distance.For using tones and your ears to set an amp’s gain, I recommend sticking with only the 40, 100, 400, or 1K Hz tones. They don\'t hurt at all. The 100 Hz tone alone will do for both subwoofer and full-range speaker amps. When a hum starts to buzzA sine wave sounds like a hum.
When it distorts, you can clearly hear it buzz. Again, the 100 Hz tone was the first to buzz, and at the exact same 51 volume setting. With the receiver at that top distortion-free level, I played the tone again and turned up the amp’s gain until I could hear the tone buzz again. Then I backed it off until the hum alone remained. The place the gain knob was set and the voltage readings were exactly the same as it had been using the scope.I did this test after working hours so no one else would be disturbed.
But I proved to myself, at least, that the ear-and-tone method worked just as well and as accurately as using a scope. The 40 Hz tone couldn\'t really be reproduced by the speakers, so was useless. The 100 Hz tone rattled everything on the desk, so it was a little difficult to pick the buzz-point out of the crowd of reverberations. The 400 Hz tone was the best tone to detect clip-points, with a very clearly defined hum-to-buzz point. I hear musicFinally, I tried music and my ears alone.
I performed this test twice, days apart, and also afterhours. Not everyone wants to hear my songs played loudly over and over again. At first, I played a favorite R&B-type song full of percussion, bass, horns, and lots of production — but I couldn’t hear it distort, only get loud. So I switched to a clear-voiced female vocalist singing swing. I also played a male singer, to see if it would be any different — it wasn’t. Your hearing gets more acute when you close your eyesI closed my eyes when I did this test, so no numbers were used to set the receiver’s top volume.
I turned it up until I heard something go wrong with the vocal — it seemed thinner, not as bell-like, and harsher. The male singer\'s voice suddenly developed a rasp. After turning the receiver down a little, restoring the fine quality of the singer’s voice, I turned up the amp gain until I heard the same thing.The two times I did this test, I got two different results. The first time, the receiver\'s maximum volume setting ended up one notch below the tones and scope setting. The second time, it was one notch higher than the tones and scope setting.
But both times, the amp gain setting was exactly the same as the other methods. The differences can’t be heardOn the first day, setting it by ear and music alone, I ended up thinking I should never turn the receiver higher than 50, and the gain was set so that at that 50 volume, the amp put out 15.7 VAC at 100 Hz, or 62 watts. On the second day, it ended up that I could turn it up to 52, and get 18.8 VAC at 100 Hz, or 88 watts. That 100 Hz tone was indeed slightly distorted visually, but it wasn\'t audible in the music.
Plus, I don\'t usually listen to music full-blast for very long periods of time, so in real use, I would likely never be able to hear the difference. It’s all about the musicI think either I was a little more or less sensitive to the singers’ voices on different days, and noticed changes at different levels than I could see in the waveforms’ shapes, or the music CDs I used were recorded at a different reference levels.
I certainly cranked some swing those evenings in the Crutchfield Lab.Whatever the differences between the methods were, they all resulted in having the receiver and amp properly gain-matched, and loud, distortion-free music ensued. Using the test tones disc was easier than listening to music. Even without the oscilloscope, the tones made it possible for me accurately set the gain. It was very easy to discern when the hum distorted into a buzz.Download some test tone files or pick up a test tone disc and try if for yourself!
Ryan from New YorkPosted on 2/5/2019I have a pioneer headunit and a mosconi amp, with these two level matching using DMM and test tones are a breeze, now I have changed to a JVC headunit with the same voltage preout, but the readings are way low using the same amp. With the pioneer I can get 25v from the amp easy, with the JVC it can barely reach 6v, tried a new JVC 2-din with same preout voltage, same result barely 6v output. Am I missing something?
Why with the pioneer I can get correct output and not with the 2 new JVC? Nathan Vetter from East AuroraPosted on Buck, could you lend some advice my way?i installed Infinity Reference 6532ix\'s (coaxial) in the rear door of my 2016 Chevy truck and Infinity Reference 9630cx\'s (components with passivize crossovers) in the front. I am also running a kicker key 180.4 amp to power these. I followed your o-scope method to the tee.
I played test tones from my phone over the Bluetooth connection and with my phone volume all the way up. I found my limiting Hz and volume level. I let the amp run it\'s auto tune with the gains all the way down and again using a pink noise tone over bluetooth from my phone.
After the auto tune finished i try to set my gians. For some reason the front channels (or amp #1 on the key) clip 1kHz with the gian all the way down. But the rears do not.
I can set the rear gains to about half way on their rotation. The resulting in cab sound is so rear heavy i cant help to think i am doing something wrong.i tried to re-do the entire process with the volume level output on my phone at the \'normal\' level (about 3/4 on its scale and where the phone automatically sets it when first connecting to a Bluetooth device). I was able to get some more range with the gains but when you switch from the Bluetooth single to a radio the volume of the radio blows you away. This cant be right either. What am i doing wrong? Buck Pomerantz from Crutchfieldon Nathan, It is my understanding that if you use the Auto Setup process for your Key 180.4, you leave the amp gain at minimum and the program automatically sets gain, balance, fade, time-alignment, high-pass filters, and EQ optimized for the front seat position or wherever you put the Setup mic. When you change settings on the amp after setup, you\'re undoing all the good tuning the amp automatically made.
Set the gain and filters of your amp with either the method outlined in this article, or by the Auto Setup process, but not both. Whites from PhiladelphiaPosted on 12/7/2018If you think it\'s the speakers than that\'s pretty disappointing - especially at $400 a pair. Do you have any experience with these speakers (Morel Tempo Ultra Components)?
However, unwinding has become big business, and there are powerful political and corporate interests that want to see it not only continue, but also expand to the unwinding of prisoners and the impoverished.Cam is a product of unwinding; made entirely out of the parts of other unwinds, he is a teen who does not technically exist. A futuristic Frankenstein, Cam struggles with a search for identity and meaning and wonders if a rewound being can have a soul. Ridding society of troublesome teens while simltaneously providing much-needed tissues for transplant might be convenient, but its morality has finally been brought into question. Rife with action and suspense, this riveting companion to the perennially popular Unwind challenges assumptions about where life begins and ends-and what it means to live.Thanks to Connor, Lev, and Risa-and their high-profile revolt at Happy Jack Harvest Camp-people can no longer turn a blind eye to unwinding. Unwholly pdf.
I bought them from Crutchfield. If they can\'t perform as well as others I might be swapping these for something else. How long is Crutchfield\'s return policy?Are other 5 1/4\' speakers able to reproduce 80hz -3db sine waves without distorting at 35% HU volume? Care to recommend any?Thanks Buck!Morel T. Whites from PhiladelphiaPosted on 12/3/2018Great read - Thank you for the info!I tried using the \'test tones by ear\' method in my setup however, and didn\'t get very far.
In trying to find the maximum HU volume, my full-range components (Morel Tempo Ultra 5 1/4\') began buzzing at a much lower HU volume than normal everyday listening volume - I\'m talking normal person listening volume. Not \'car audio enthusiast\' volume haha. Using -3db sine waves in the 60- 100hz range, my woofers began buzzing at approx 35% HU volume. Surely these speakers should be able to take about 35% of HU volume with no eq boosts and the amp gains turned down. In addition, I also have my HU\'s HPF set to 80hz with an -18db cutoff slope so they aren\'t even running \'full range\'.So what gives? Why would I be getting a distortion buzz at such low HU volume?
Are sine wave test tones in the 60-100hz range not appropriate for testing full range speakers using the \'test tones by ear\' method? Logically it seems appropriate since theres lots of activity going on in that frequency range, normally played at higher levels than 35% HU volume. Any insight would be greatly appreciated.The equipment chain in question is.HU - Pioneer AVH-1440NEX (No \'Bass Boost\' or eq boosts - HPF @80hz w/ -18db Cutoff slope)Amp - Alpine PDR-V75 (gains set low - no \'Bass boost\' or HPF applied)Speakers - Morel Tempo Ultra 5 1/4\' ComponentsThank you for your time and for sharing your knowledge! Brandon from CharlestonPosted on 7/31/2018After further testing, I\'ve discovered it\'s only the right midrange woofer making the noise, but the strange part is that I\'m not sure it\'s distortion. It almost sounds like a faint telephone beep tone.
I swapped that speaker\'s wires to the left crossover, which is run by channel one, to rule that out. The issue persisted.
I disconnected all other speakers to make sure it wasn\'t a polarity issue, but issue persisted. Played the left driver and the tone was gone. What the heck is going on? Maybe that one speaker wire is picking up noise somewhere in the car?
Seems strange since both channel\'s wire is run side by side on the passenger side. Butch from Montgomery Vlg MDPosted on 7/5/2018Thank you for your response, Buck. I will try the 100Hz tone (maybe the others too) for both the 4channel Pioneer GM 8604 and the SSL LoPro10 sub. I don\'t detect distortion from my camry 2016 head unit even at full blast (with amp turned down) so I tune at 75% volume.
Maybe using your method, I will finally get the best of my PolkDB6502s and my 70RMS rear 6x9 kickers. My problem is that I want it to sound as clear and clean as my home sound system, which is really impossible. I really appreciate the clear response (perhaps dumbed-down for me, thank goodness) and the informative article. Sincerely appreciated. Buck Pomerantz from Crutchfieldon 6/29/2018 Butch, I think you\'re referring to an amp gain setting technique that uses a volt meter to attain a target output voltage that matches the desired output wattage.
I do not recommend that way of setting gain because it doesn\'t take into account whether or not the source is clipping, nor the accuracy of the meter at any frequency besides 60 Hz. Playing a distorting tone loudly might eventually damage a speaker, but not for the short time needed to set an amp\'s gain. Matthew from PensacolaPosted on 5/16/2018Nice article but for some reason, every single article I\'ve read regarding amp tuning, ( I\'ve read dozens of them from many different websites) every single one leaves out a key factor and I can\'t for the life of me figure out why it gets left out or why no one ever seems to ask. Maybe it\'s just me I\'m not sure, very well could be. My question is, where do you set the crossover on the amp when setting gains since every single person who makes a tutorial neglects to mention it. Perhaps it isn\'t important at all whatsoever since it\'s never mentioned.
Perhaps it\'s an industry secret that isn\'t suppose to be talked about to those who don\'t already know about it. Think Fight Club. Regardless, can someone please please pretty please tell me once and for all what I\'m suppose to do with the crossover on my amp when playing test tones to set my gains. I promise to never speak of it to anyone ever. I will guard the secret with my life I swear. Plz and thank you.
Buck Pomerantz from CrutchfieldPosted on 3/9/2018John, Multimeters read RMS voltage. So attaining an output of 30 volts RMS through a 2-ohm load produces 450 watts RMS.
You can measure the signal\'s peak-to-peak voltage with your scope, as well as see when it clips. The only harm you can do to a sub by playing a 50 Hz tone is if you play it too loud.
If your amplifier is rated higher than your sub, setting gain with an oscilloscope won\'t work - the sub\'s sound will distort before the amplified waveform shows any distortion at all. JohnPosted on 3/8/2018When setting the gain of my amp I\'m targeting 30Vp-p for a 450W output on my 2ohm sub. The gain setting for my amp to get 30V on my multimeter gives me about 80V on my scope.This must be due to the low input impedance of the scope giving unrealistic output from the amp. I don\'t have a dummy 2 ohm load rated for that kind of power.
Is it okay to play a 50 Hz test tone on my actual sub or will I damage it? I figure a reading with the scope under the actual load is the best way to optimize the power output of the amp.My amp rating is higher than my sub so I want to push it as much as I can without damage. Clipping doesn\'t seem to be a problem for me.Thanks!John. Buck Pomerantz from CrutchfieldPosted on 2/2/2018Brian, The spikes you see are probably more an artifice of your oscilloscope\'s response-time than the clipped signal\'s harmonic radiation.
Clipped signals, as you noticed, don\'t always take the form of a square wave. What you\'re also witnessing is the fact that your gear clips different frequencies at different levels. Find out which frequency at which the receiver first clips and use that frequency tone to set your amp gains. For example, if your receiver clips 4k Hz at a lower volume setting than any other signal, you\'d use that tone to set amp gains. Also, the amp gains should be re-set after any EQ or tone adjustments are applied. From HoustonPosted on 2/1/2018So I\'ve been messing around with my oscilloscope to set the gains on two amps. My head unit is a pioneer AVH X2800bs4 channel pioneer GM D8604JL Audio j2 500.1 monoblockWhen I isolate the head unit I\'m checking the max output through the rca cables with a 0dB test tone suite I made.
Once I found the max receiver volume at 0dB I disconnected all speakers and plugged the rca pre-amps back in. What is interesting to me is the 4channel amp when playing a test tone at max unclipped rca output does not form a square wave but starts to spike in the center with what looks like harmonic destabilizing centered around the wave peak which if gain is further increases shows the expected flat top however it still contains a sharp spike at the start and end of the square peak. Could this just be an artifact of class d amplifiers?Also when I set 1kHz to max unclipped amplification then check 4kHz and 8Khz the higher frequencies show \'sine like\' waveforms but the shape is somewhat distorted.
And even when maxed out on the gain the 4-8kHz don\'t show up as a flat topped wave but rapidly spike the voltage and appear completely garbled.So to much question. Should I be setting the gain based on the 1kHz signal or let the higher frequencies set the ceiling?. Dann Combs from Colorado Springs, COPosted on 11/2/2017Thanks Buck.
I\'ve read versions of these approaches at least two dozen times in my quest to educate myself but yours is the most clear and concise. Well written.
I do have one question though.How do I incorporate remote level control on the amp (SoundStream PN1.650D) in this process? This amp has a gain control, a bass boost control, and an external remote level control.
I am not going to use the 45 Hz bass boost and will just leave that dialed all the way down to minimum. I have an oscilloscope and understand the process. Tl wn851n drivers for mac.
But I\'ve seen no advice regarding the remote control. Is that simply another gain control knob? Or is it in some way different from the gain control dial on the amp? If it\'s just another gain control then my inclination is to set it to the max and leave it there, setting the on amp dial to minimum and turning the on amp dial up until I find clipping, backing it off to the clean signal point and leave it there permanently.
Then, while playing music I could use the remote knob to turn down the bass to desired levels, knowing that I could not worry about turning it up to max if desired. Is that the right approach? Or what is recommended for working with both the gain dial and the remote knob in the gain setting process?Thanks again. Glennon heinrich from macedonPosted on 9/26/2017Okay so I\'ve been running 2 Infinity Kappa 100.9 W\'s in a sealed box with passive radiators tune to 27 Hertz and it sounds phenomenal at 600 RMS each even though they\'re rated for like 375. I\'ve since switched the speakers to 4 ohm to introduce a 2 ohm load and then I wired in a 12 inch earthquake dbxi in parallel to bring it back to a 1 ohm load. And now it doesn\'t sound nearly as good but an R&B it\'s definitely louder and shakes everything more.
Could that be because the 12 is in a sealed box would it sound better if I get that box tuned to the same frequency as the other. In the pr enclosure those subs take 600 watts RMS all the way down to 12 Hertz then you start to get mechanical noise I\'ve only done it once lol. Brian from Bay AreaPosted on 9/7/2017Hey Buck, fantastic article! I can wait to try all this stuff out next week.Couple things:When you\'re determining your HU\'s max clean volume, your gains at that point are at the minimum, right? If you were to have the gain somewhere else but still on the lower end, (say 10% or 20%), would the distortion point on the HU vary in any way?Also, if I want to leave some room to play with for my subs, I\'m assuming I should set the HU\'s sub control to its max or at least whatever number I want to use as my max when setting the gain, correct?And lastly, which is better? Running two 500 RMS subs at 4 Ohms with an amp that puts out a max of 1100 at 4 Ohms, or the same two subs at 2 Ohms where the same amp puts out 2000 at 2 Ohms? Is the amp working harder in the first scenario vs the second?Thanks!.
Buck Pomerantz from CrutchfieldPosted on 5/3/2017Cody, The misuse of low-pas filters (HPF) and bass boosts lead to the destruction of many subwoofers. Both are equalizers used to optimize the tone of the bass sound.
A low-pass filter gets engaged to remove the high-frequency notes you don\'t want the sub to play. Turning it \'all the way up\' is not the proper way to set it.
Check out for that. A bass boost gets engaged when you want to emphasize the lowest bass notes, around the low E of a bass guitar or piano. If you like the tone when using a bass boost, you must readjust the amp\'s gain control to compensate for the boost in over-all volume and ensure that no dangerous distortion ever plays.
Achieving full power in an amplifier depends on setting the gain correctly, not on the tone of the bass signal. Cody from Scott AFBPosted on 5/2/2017Sir/Ma\'am,So I have an Orion Step to 122d 12\' sub rated 1500 RMS and an Orion amp 1500 RMS and i fried a sub after it was professuonally tuned.So basically to tune properly the LPF needs to be all the way up along with the volume at the proper level then adjust the gain till it clips/distorts/buzzes right?So what\'s the purpose of having bass boost? Basically I want to push all 1500 RMS or close to it but not sure you could do that without bass boost.Also, I have a yellow top batt ran to my primary and my amp ran to the yellow top so it has a standalone battery all for itself. Cory from long beachPosted on 2/14/2017I have read some tutorials stating that you should only use the scope and test tone to set the gain up to the voltage calculated by the units actual power and the 4 ohms, and not the clipping point. The difference being that the former is the manufacturers recommended limit for \'stable\' power, and though there may be headroom between that number and the clipping point (your extra found power), it was not necessarily stable there.
Do you have any insight on that?. Buck Pomerantz from CrutchfieldPosted on 9/19/2016Tendai, The gremlin\'s in your multi-meter - it\'s only accurate at 60 Hz.
And you didn\'t say what the impedance of your subs are. 20 volts AC through a 2-ohm sub, for instance, generates 200 watts RMS. Another complication that you might not be aware of is that the impedance of a speaker or sub changes with different frequencies, and its output power does as well. Trying to set amp gain using an inaccurate meter reading the voltage of different frequencies through an unknown impedance will not work very well.
If you have an oscilloscope, use that to set your amp gains, it will result in a more accurate setting. Tendai from DerbyPosted on 9/19/2016Hi again BuckThanks for that. I\'d purchased a DSO 112 O\'scope which was en route when I asked. I\'ve since hooked it up to the amp and set the gain using 1000Hz tone for the mids and 40/50 tones for the 8 inch woofers cutting the gain to about 10% before clipping.That said I then went on to check the output voltages after all had been set with lovely sine waves on the scope. Strangely channels 1 and 2 show voltages of 17.5 and 16.5 even though I set them both to high pass at the same level (180 as per mfr).Stranger still channels 3 and 4 which are for the woofers low passed at (100Hz as per Mosconi) show voltages of 20-21 without any sign of distortion.Is there a family of gremlins in the amp?.
Tendai from Derby, UKPosted on 9/10/2016Hi BuckGreat article. Still a bit confused.
I have a Mosconi 130.4 DSP amp rated at 130RMS per channel at 4 ohms or 175RMS at 2 ohms. My speakers are Gladen 201 3 way with 4x150/100 rating at 3 ohms in a BMW E60 UK spec with 2 channels being 8 inch subs and 2 channels feeding doorcard midbases plus tweeters via a crossover. I take the 100 to be the nominal rating in that? What target voltage would you recommend if I were to use a DMM? I\'ve tried setting by ear but the E60 BMW does not have a visual for the volume so it\'s difficult to tell when one has hit 3/4 volume etc etc plus the buttons can be pressed til time immemorial without one having the foggiest whether you\'ve hit the top, mid-top, somewhere-top, not-so-top etc. Buck Pomerantz from CrutchfieldPosted on 8/2/2016Kenyon, Test tones and oscilloscopes are commonly used to set gains in audio equipment - a device\'s input sensitivity to the output of a preceding device in a system.
You can download \'0-dB\' test tones for free from the internet - a web search will turn up a vast selection. After downloading, you can burn them to a CD or store them onto a thumb drive for playing later. You then use the oscilloscope to visualize the tone as a sine wave - when the sine wave distorts, it means the signal\'s clipping and the gain needs to be reduced. I can\'t think of any reason to use test tones and an oscilloscope to set an equalizer or a crossover, however. For those, people often use pink noise and an RTA (real-time analyzer).
Buck Pomerantz from CrutchfieldPosted on 4/8/2016Zack, A subwoofer voice coil presents an inductive load, not a resistive load, to an amplifier\'s output - so measuring a coil\'s DC resistance with a multimeter won\'t accurately tell you its impedance. A coil\'s impedance actually changes according to the frequency of the signal played. Using the manufacturer\'s \'nominal\' impedance rating will bring the best results. Just be sure, when setting the gain, that your source is at its highest level with no clipping and your multimeter is accurate at the frequency of the tone you use. Most meters only read accurate AC RMS voltage around 60 Hz.
(PS: producing 300 watts through a 2-ohm load takes 24.5 volts.). Zack from EulessPosted on 4/8/2016I plan on setting my gain using a multimeter and calculating the max volts I should see for my sub. The reason is that I have a 12\' DVC sub wired in parallel that can handle 300 watts RMS, but the Alpine amp powering it can put out 500 watts RMS in 2-ohm mode. So I need to calculate how many volts 300 watts RMS is, then set the gain to that level.In doing my math, should I first test the positive/negative speaker lead to the sub to get the exact ohms for my calculation? Or is just going with 2-ohms okay? I\'m just concerned that different subs/speaker runs may introduce resistance variation, and I\'m trying to be accurate.
Ken Lacy from BaxterPosted on 8/24/2015Please help? I have installed a Pyle 5 channel amp 6800 watts into a chevy cruze. Powering an alpine 12\' sub rated for 1000 rms.
Power from Batt measures 14.2 at the amp. Ground is good from the amp to the frame. 17ft rca\'s from the stock head unit with a pac AAGM-44 adapter to give me the rca outputs. Everything is brand new. All settings on hu and amp set to minimum or 0 - volume at 75%. I play the 50hz sounds and my multimeter starts at 6 volts and i turn the gain all the way up and the highest voltage i get is 44. I have two other gain adjusters for the other 4 channels and the highest reading i get on either of them is 42.
My 2 ohm sub calls for 48 watts. Everything I read from others doing it, they can get the readings up over 60 watts and gain not even turned up all the way.Any ideas why I am getting less than normal wattage readings?.
The audio test tones below are available for free download and use in your projects. Select the tone you wish to download and click the corresponding format of your choice (or right-click and select \'Save link as..\'). All files are mono, sampled at 44100Hz, 16-bit. If you\'re not sure which tone you want, 1kHz is a safe bet.
...'>1000 Hz Test Tone(24.04.2020)Tone Frequency Duration Download: 100Hz 0:05.00 wav (0.4MB) mp3 (0.1MB) 0:30.00 wav (2.5MB) mp3 (0.5MB) 250Hz 0:05.00 wav (0.4MB) mp3 (0.1MB) 0:30.00 wav (2.5MB) mp3 (0.5MB) 440Hz 0:05.00 wav (0.4MB) mp3 (0.1MB) 0:30.00 wav (2.5MB) mp3 (0.5MB) 1kHz 0:05.00 wav (0.4MB) mp3 (0.1MB) 0:30.00 wav (2.5MB) mp3 (0.5MB) 10kHz 0:05.00 wav (0.4MB) mp3 (0.1MB) 0:30.00 wav (2.5MB) mp3 (0.5MB) Oct 24, 2011 10 mins of 1000 hz for tuning. Manifest Love & Relationships Healing, Law Of Attraction Enhance Love Energy, 639Hz Meditation Music SUPERNATURAL BRAINWAVE POWER 713 watching Live now.
I\'ve been tinkering with electronics ever since I was a kid - starting with taking apart and putting back together televisions and radios. I always got them back together again and working. I took courses in radio and electronics as a teenager, and became a ham radio operator. I worked in my high school\'s stage crew, running sound, lights, and a movie projector. After college, I joined a rock \'n roll band as the soundman and learned how to lug around and operate the gear that helps make music sound good and loud.Working in a music store in Austin, Texas, I spent a few years manufacturing, installing, repairing, and operating sound systems.
Our customers were recording studios, nightclubs, and touring bands. Eventually I moved back to Charlottesville, Virginia and opened a small demo recording studio. In 2006, I finally came to my senses and got this job at Crutchfield. They actually pay me to ramble on, rant, and explain the things I love about music, electronics, and getting good sound.Given my background, they put me to work writing about some of the most complex electronic products Crutchfield sells: car amplifiers, digital signal processors, wiring, professional sound mixers, and PA systems. Buck in the Crutchfield LabsIn an amplified car system, you need to set your amplifier’s gain correctly in order to enjoy your music’s full range of dynamics and frequency response — hearing all the notes clearly, whether loud or soft. You’ll feel your music’s impact better and hear exciting details that otherwise would get lost in your car.There\'re quite a few ways to set gain, but I think listening to test tones is the simplest method giving the best results. Continue reading the article if you want to see how I came to this conclusion by my researching the isssue in the Crutchfield Labs.
Instructions for setting amp gain using test tones. Download 0 dB sine wave test tones of 40, 100, 400, 800, and 1000 Hz to your preferred medium (disc, chip, file, phone). Set your receiver’s EQ presets and the amp’s bass boost to the way you normally listen to your music. With the amp gain at minimum, play the 40 Hz tone and turn up the receiver’s volume until you hear it buzz. An example of a a clean waveform (left) and a distorted, clipped wave (right) 2. Test tones and speakersBut seeing as most people don’t have oscilloscopes, I thought that maybe by listening to the tones through speakers, one could also set an amplifier’s gain correctly. A non-distorted sine wave test tone sounds like a pure hum.
When it distorts, you can clearly hear it buzz. By using test tones played through a speaker, I wondered how accurately I could set an amp’s gain as compared to setting it by the other methods. A deep dive into my Crutchfield Labs projectI went into The Crutchfield Labs and set up an amplifier, wired to a power supply, a car receiver, and a pair of speakers. I also attached two sets of probes to a pair of speaker wires, one going to a voltage meter and the other to an oscilloscope. This way, we could see what the sounds look like and read the resulting power level the amp produced.
Pioneer DEH-3400UB First set the tone controls to the way you listenThe receiver\'s and amp’s EQ and crossovers needed to be set to where they normally would be when playing music. This is so the gain would be set under real-world conditions.
Adding boost, at any frequency, after setting the gain, can make the amp clip, distorting the sound and endangering speakers and subs.I let the receiver (a Pioneer DEH-3400UB) stay in its factory preset “Dynamic” EQ setting, which boosts the bass and treble for a fuller sound. That meant certain frequencies would play louder than others. I needed to find out which tone clipped the receiver first, at the lowest volume setting. Then, I needed to use that receiver volume setting at that tone’s frequency to set the amp’s gain. Part 1: Setting the gain with the oscilloscope How loud can the receiver play and still play clean?I started with the amp’s gain set to its minimum, and the speakers disconnected. I played the first tone, 40 Hz, a low bass note, only fit for subwoofers, and set the scope to view the sine wave. Then I turned up the receiver’s volume until I could see something bizarre happening to the wave’s shape. It didn’t “clip” at the top and bottom, it distorted in the middle.
But I could see exactly at what volume level the distortion first appeared, and where it disappeared.I took note of what the receiver’s volume reading was: 52. (The receiver’s top volume number was 62.) That meant the receiver played 40 Hz clean and at its loudest at its “52” volume. Test Tone CD Track 740 HzMaximum Clean Volume = 52Test Tone CD Track 8100 HzMaximum Clean Volume = 51Test Tone CD Track 9400 HzMaximum Clean Volume = 57Test Tone CD Track 101K HzMaximum Clean Volume = 59Test Tone CD Track 114K HzMaximum Clean Volume = 56Test Tone CD Track 128K HzMaximum Clean Volume = 55This receiver plays loudest at volume 51, otherwise 100 Hz notes would clipI measured the receiver’s distortion-free top volumes for the other test tones on the disc. The 100 Hz tone stood out as the strongest — I had to turn the volume to its lowest setting to get it to play clean. Because that volume represented the level that all the tones would play cleanly through the receiver, I used the 51 setting for the receiver’s volume for the next step. Because the 100 Hz tone was the strongest, and would clip the amp first, I used the 100 Hz test tone to set the amp\'s gain.
Sound Ordnance M-4050 The amplifier’s turnI played the tone and looked at the sine wave while turning up the amplifier’s gain knob. Any waveform distortion I then saw came from the amp, not the receiver. Turning the gain back down until the distortion disappeared, I set the gain exactly where the amp and receiver were both at their maximum clean output levels: perfectly gain-matched. Setting the gain right optimizes the amp’s outputI turned up the gain to the amp’s top clean-playing point and read the volt meter. The volt meter read AC (alternating current) voltage, and the amp I used (a Sound Ordnance M-4050 4-channel) showed a top clean output for 100 Hz of 17.6 VAC.
That translated to about 77 watts. Not bad for an amp rated at 50 watts RMS per channel. Bench testing results in higher power readingsWhat was going on was the power supply the receiver and amp used was 13.5 volts DC, about the same as a running car’s system usually provides, but the amp wasn\'t connected to the speakers and so wasn\'t loading down the power supply with the increased current demand of the speakers. That explained some of the “extra” power. But the amp definitely performed above its specified rating.
If I had wanted to, I could have set the amp’s output to exactly 50 watts, by turning the gain down until the voltage read a targeted number, in this case 14.14 volts AC. Math formulas — skip this paragraphThe wattage equals the voltage squared divided by the speaker’s impedance in ohms, 4 ohms in most cases. The voltage equals the square-root of the product of the wattage times the speaker’s impedance (also usually 4). 50 watts times 4 ohms equals 200; the square-root of which is 14.14 volts AC. 14.14 volts through 4 ohms of impedance creates 50 watts of power.
These formulae are based on Ohm’s and Joule’s Laws and you can’t break them if you tried. A note on multimeter accuracyTo accurately measure your amplifier’s output power with a multimeter, use a 60 Hz tone for a subwoofer amp, and a 100 Hz tone for a full-range amp with its high-pass filter turned off. This is because most meters are made to measure AC voltage accurately at 50-60 Hz (the common frequency of all power systems around the world). Using a standard hand-held multimeter to measure the voltage of a higher-frequency signal results in readings that are much lower and leads to inaccurate power calculations. For instance, the Amprobe 15XP-B multimeter I used in this Labs demonstration reads the voltage of a 0 dB 1 KHz signal about one-fifth the level that it reads at 40 Hz or 100 Hz.
This would result in a calculated wattage about one-twentieth of the correct output power. Different meters will have different degrees of deviation. Kenwood KFC-6984PS Part 2: Setting the gain using speakers and my ears The noisy part of the testI then repeated the whole performance with one speaker connected — a Kenwood KFC-6984PS 6\'x9\' 4-way. I want to say, in advance, that this was not a pleasant experience. Two hours later, my ears were still painfully ringing from the very high 8K Hz tone. Jordan, also in the Labs area at the time, complained that the 4K Hz tone was still ringing in his.
This method can produce high-pitched, annoying, ear-drilling sounds that could hurt your hearing if you expose yourself for too long, and definitely will bother everyone within listening distance.For using tones and your ears to set an amp’s gain, I recommend sticking with only the 40, 100, 400, or 1K Hz tones. They don\'t hurt at all. The 100 Hz tone alone will do for both subwoofer and full-range speaker amps. When a hum starts to buzzA sine wave sounds like a hum.
When it distorts, you can clearly hear it buzz. Again, the 100 Hz tone was the first to buzz, and at the exact same 51 volume setting. With the receiver at that top distortion-free level, I played the tone again and turned up the amp’s gain until I could hear the tone buzz again. Then I backed it off until the hum alone remained. The place the gain knob was set and the voltage readings were exactly the same as it had been using the scope.I did this test after working hours so no one else would be disturbed.
But I proved to myself, at least, that the ear-and-tone method worked just as well and as accurately as using a scope. The 40 Hz tone couldn\'t really be reproduced by the speakers, so was useless. The 100 Hz tone rattled everything on the desk, so it was a little difficult to pick the buzz-point out of the crowd of reverberations. The 400 Hz tone was the best tone to detect clip-points, with a very clearly defined hum-to-buzz point. I hear musicFinally, I tried music and my ears alone.
I performed this test twice, days apart, and also afterhours. Not everyone wants to hear my songs played loudly over and over again. At first, I played a favorite R&B-type song full of percussion, bass, horns, and lots of production — but I couldn’t hear it distort, only get loud. So I switched to a clear-voiced female vocalist singing swing. I also played a male singer, to see if it would be any different — it wasn’t. Your hearing gets more acute when you close your eyesI closed my eyes when I did this test, so no numbers were used to set the receiver’s top volume.
I turned it up until I heard something go wrong with the vocal — it seemed thinner, not as bell-like, and harsher. The male singer\'s voice suddenly developed a rasp. After turning the receiver down a little, restoring the fine quality of the singer’s voice, I turned up the amp gain until I heard the same thing.The two times I did this test, I got two different results. The first time, the receiver\'s maximum volume setting ended up one notch below the tones and scope setting. The second time, it was one notch higher than the tones and scope setting.
But both times, the amp gain setting was exactly the same as the other methods. The differences can’t be heardOn the first day, setting it by ear and music alone, I ended up thinking I should never turn the receiver higher than 50, and the gain was set so that at that 50 volume, the amp put out 15.7 VAC at 100 Hz, or 62 watts. On the second day, it ended up that I could turn it up to 52, and get 18.8 VAC at 100 Hz, or 88 watts. That 100 Hz tone was indeed slightly distorted visually, but it wasn\'t audible in the music.
Plus, I don\'t usually listen to music full-blast for very long periods of time, so in real use, I would likely never be able to hear the difference. It’s all about the musicI think either I was a little more or less sensitive to the singers’ voices on different days, and noticed changes at different levels than I could see in the waveforms’ shapes, or the music CDs I used were recorded at a different reference levels.
I certainly cranked some swing those evenings in the Crutchfield Lab.Whatever the differences between the methods were, they all resulted in having the receiver and amp properly gain-matched, and loud, distortion-free music ensued. Using the test tones disc was easier than listening to music. Even without the oscilloscope, the tones made it possible for me accurately set the gain. It was very easy to discern when the hum distorted into a buzz.Download some test tone files or pick up a test tone disc and try if for yourself!
Ryan from New YorkPosted on 2/5/2019I have a pioneer headunit and a mosconi amp, with these two level matching using DMM and test tones are a breeze, now I have changed to a JVC headunit with the same voltage preout, but the readings are way low using the same amp. With the pioneer I can get 25v from the amp easy, with the JVC it can barely reach 6v, tried a new JVC 2-din with same preout voltage, same result barely 6v output. Am I missing something?
Why with the pioneer I can get correct output and not with the 2 new JVC? Nathan Vetter from East AuroraPosted on Buck, could you lend some advice my way?i installed Infinity Reference 6532ix\'s (coaxial) in the rear door of my 2016 Chevy truck and Infinity Reference 9630cx\'s (components with passivize crossovers) in the front. I am also running a kicker key 180.4 amp to power these. I followed your o-scope method to the tee.
I played test tones from my phone over the Bluetooth connection and with my phone volume all the way up. I found my limiting Hz and volume level. I let the amp run it\'s auto tune with the gains all the way down and again using a pink noise tone over bluetooth from my phone.
After the auto tune finished i try to set my gians. For some reason the front channels (or amp #1 on the key) clip 1kHz with the gian all the way down. But the rears do not.
I can set the rear gains to about half way on their rotation. The resulting in cab sound is so rear heavy i cant help to think i am doing something wrong.i tried to re-do the entire process with the volume level output on my phone at the \'normal\' level (about 3/4 on its scale and where the phone automatically sets it when first connecting to a Bluetooth device). I was able to get some more range with the gains but when you switch from the Bluetooth single to a radio the volume of the radio blows you away. This cant be right either. What am i doing wrong? Buck Pomerantz from Crutchfieldon Nathan, It is my understanding that if you use the Auto Setup process for your Key 180.4, you leave the amp gain at minimum and the program automatically sets gain, balance, fade, time-alignment, high-pass filters, and EQ optimized for the front seat position or wherever you put the Setup mic. When you change settings on the amp after setup, you\'re undoing all the good tuning the amp automatically made.
Set the gain and filters of your amp with either the method outlined in this article, or by the Auto Setup process, but not both. Whites from PhiladelphiaPosted on 12/7/2018If you think it\'s the speakers than that\'s pretty disappointing - especially at $400 a pair. Do you have any experience with these speakers (Morel Tempo Ultra Components)?
However, unwinding has become big business, and there are powerful political and corporate interests that want to see it not only continue, but also expand to the unwinding of prisoners and the impoverished.Cam is a product of unwinding; made entirely out of the parts of other unwinds, he is a teen who does not technically exist. A futuristic Frankenstein, Cam struggles with a search for identity and meaning and wonders if a rewound being can have a soul. Ridding society of troublesome teens while simltaneously providing much-needed tissues for transplant might be convenient, but its morality has finally been brought into question. Rife with action and suspense, this riveting companion to the perennially popular Unwind challenges assumptions about where life begins and ends-and what it means to live.Thanks to Connor, Lev, and Risa-and their high-profile revolt at Happy Jack Harvest Camp-people can no longer turn a blind eye to unwinding. Unwholly pdf.
I bought them from Crutchfield. If they can\'t perform as well as others I might be swapping these for something else. How long is Crutchfield\'s return policy?Are other 5 1/4\' speakers able to reproduce 80hz -3db sine waves without distorting at 35% HU volume? Care to recommend any?Thanks Buck!Morel T. Whites from PhiladelphiaPosted on 12/3/2018Great read - Thank you for the info!I tried using the \'test tones by ear\' method in my setup however, and didn\'t get very far.
In trying to find the maximum HU volume, my full-range components (Morel Tempo Ultra 5 1/4\') began buzzing at a much lower HU volume than normal everyday listening volume - I\'m talking normal person listening volume. Not \'car audio enthusiast\' volume haha. Using -3db sine waves in the 60- 100hz range, my woofers began buzzing at approx 35% HU volume. Surely these speakers should be able to take about 35% of HU volume with no eq boosts and the amp gains turned down. In addition, I also have my HU\'s HPF set to 80hz with an -18db cutoff slope so they aren\'t even running \'full range\'.So what gives? Why would I be getting a distortion buzz at such low HU volume?
Are sine wave test tones in the 60-100hz range not appropriate for testing full range speakers using the \'test tones by ear\' method? Logically it seems appropriate since theres lots of activity going on in that frequency range, normally played at higher levels than 35% HU volume. Any insight would be greatly appreciated.The equipment chain in question is.HU - Pioneer AVH-1440NEX (No \'Bass Boost\' or eq boosts - HPF @80hz w/ -18db Cutoff slope)Amp - Alpine PDR-V75 (gains set low - no \'Bass boost\' or HPF applied)Speakers - Morel Tempo Ultra 5 1/4\' ComponentsThank you for your time and for sharing your knowledge! Brandon from CharlestonPosted on 7/31/2018After further testing, I\'ve discovered it\'s only the right midrange woofer making the noise, but the strange part is that I\'m not sure it\'s distortion. It almost sounds like a faint telephone beep tone.
I swapped that speaker\'s wires to the left crossover, which is run by channel one, to rule that out. The issue persisted.
I disconnected all other speakers to make sure it wasn\'t a polarity issue, but issue persisted. Played the left driver and the tone was gone. What the heck is going on? Maybe that one speaker wire is picking up noise somewhere in the car?
Seems strange since both channel\'s wire is run side by side on the passenger side. Butch from Montgomery Vlg MDPosted on 7/5/2018Thank you for your response, Buck. I will try the 100Hz tone (maybe the others too) for both the 4channel Pioneer GM 8604 and the SSL LoPro10 sub. I don\'t detect distortion from my camry 2016 head unit even at full blast (with amp turned down) so I tune at 75% volume.
Maybe using your method, I will finally get the best of my PolkDB6502s and my 70RMS rear 6x9 kickers. My problem is that I want it to sound as clear and clean as my home sound system, which is really impossible. I really appreciate the clear response (perhaps dumbed-down for me, thank goodness) and the informative article. Sincerely appreciated. Buck Pomerantz from Crutchfieldon 6/29/2018 Butch, I think you\'re referring to an amp gain setting technique that uses a volt meter to attain a target output voltage that matches the desired output wattage.
I do not recommend that way of setting gain because it doesn\'t take into account whether or not the source is clipping, nor the accuracy of the meter at any frequency besides 60 Hz. Playing a distorting tone loudly might eventually damage a speaker, but not for the short time needed to set an amp\'s gain. Matthew from PensacolaPosted on 5/16/2018Nice article but for some reason, every single article I\'ve read regarding amp tuning, ( I\'ve read dozens of them from many different websites) every single one leaves out a key factor and I can\'t for the life of me figure out why it gets left out or why no one ever seems to ask. Maybe it\'s just me I\'m not sure, very well could be. My question is, where do you set the crossover on the amp when setting gains since every single person who makes a tutorial neglects to mention it. Perhaps it isn\'t important at all whatsoever since it\'s never mentioned.
Perhaps it\'s an industry secret that isn\'t suppose to be talked about to those who don\'t already know about it. Think Fight Club. Regardless, can someone please please pretty please tell me once and for all what I\'m suppose to do with the crossover on my amp when playing test tones to set my gains. I promise to never speak of it to anyone ever. I will guard the secret with my life I swear. Plz and thank you.
Buck Pomerantz from CrutchfieldPosted on 3/9/2018John, Multimeters read RMS voltage. So attaining an output of 30 volts RMS through a 2-ohm load produces 450 watts RMS.
You can measure the signal\'s peak-to-peak voltage with your scope, as well as see when it clips. The only harm you can do to a sub by playing a 50 Hz tone is if you play it too loud.
If your amplifier is rated higher than your sub, setting gain with an oscilloscope won\'t work - the sub\'s sound will distort before the amplified waveform shows any distortion at all. JohnPosted on 3/8/2018When setting the gain of my amp I\'m targeting 30Vp-p for a 450W output on my 2ohm sub. The gain setting for my amp to get 30V on my multimeter gives me about 80V on my scope.This must be due to the low input impedance of the scope giving unrealistic output from the amp. I don\'t have a dummy 2 ohm load rated for that kind of power.
Is it okay to play a 50 Hz test tone on my actual sub or will I damage it? I figure a reading with the scope under the actual load is the best way to optimize the power output of the amp.My amp rating is higher than my sub so I want to push it as much as I can without damage. Clipping doesn\'t seem to be a problem for me.Thanks!John. Buck Pomerantz from CrutchfieldPosted on 2/2/2018Brian, The spikes you see are probably more an artifice of your oscilloscope\'s response-time than the clipped signal\'s harmonic radiation.
Clipped signals, as you noticed, don\'t always take the form of a square wave. What you\'re also witnessing is the fact that your gear clips different frequencies at different levels. Find out which frequency at which the receiver first clips and use that frequency tone to set your amp gains. For example, if your receiver clips 4k Hz at a lower volume setting than any other signal, you\'d use that tone to set amp gains. Also, the amp gains should be re-set after any EQ or tone adjustments are applied. From HoustonPosted on 2/1/2018So I\'ve been messing around with my oscilloscope to set the gains on two amps. My head unit is a pioneer AVH X2800bs4 channel pioneer GM D8604JL Audio j2 500.1 monoblockWhen I isolate the head unit I\'m checking the max output through the rca cables with a 0dB test tone suite I made.
Once I found the max receiver volume at 0dB I disconnected all speakers and plugged the rca pre-amps back in. What is interesting to me is the 4channel amp when playing a test tone at max unclipped rca output does not form a square wave but starts to spike in the center with what looks like harmonic destabilizing centered around the wave peak which if gain is further increases shows the expected flat top however it still contains a sharp spike at the start and end of the square peak. Could this just be an artifact of class d amplifiers?Also when I set 1kHz to max unclipped amplification then check 4kHz and 8Khz the higher frequencies show \'sine like\' waveforms but the shape is somewhat distorted.
And even when maxed out on the gain the 4-8kHz don\'t show up as a flat topped wave but rapidly spike the voltage and appear completely garbled.So to much question. Should I be setting the gain based on the 1kHz signal or let the higher frequencies set the ceiling?. Dann Combs from Colorado Springs, COPosted on 11/2/2017Thanks Buck.
I\'ve read versions of these approaches at least two dozen times in my quest to educate myself but yours is the most clear and concise. Well written.
I do have one question though.How do I incorporate remote level control on the amp (SoundStream PN1.650D) in this process? This amp has a gain control, a bass boost control, and an external remote level control.
I am not going to use the 45 Hz bass boost and will just leave that dialed all the way down to minimum. I have an oscilloscope and understand the process. Tl wn851n drivers for mac.
But I\'ve seen no advice regarding the remote control. Is that simply another gain control knob? Or is it in some way different from the gain control dial on the amp? If it\'s just another gain control then my inclination is to set it to the max and leave it there, setting the on amp dial to minimum and turning the on amp dial up until I find clipping, backing it off to the clean signal point and leave it there permanently.
Then, while playing music I could use the remote knob to turn down the bass to desired levels, knowing that I could not worry about turning it up to max if desired. Is that the right approach? Or what is recommended for working with both the gain dial and the remote knob in the gain setting process?Thanks again. Glennon heinrich from macedonPosted on 9/26/2017Okay so I\'ve been running 2 Infinity Kappa 100.9 W\'s in a sealed box with passive radiators tune to 27 Hertz and it sounds phenomenal at 600 RMS each even though they\'re rated for like 375. I\'ve since switched the speakers to 4 ohm to introduce a 2 ohm load and then I wired in a 12 inch earthquake dbxi in parallel to bring it back to a 1 ohm load. And now it doesn\'t sound nearly as good but an R&B it\'s definitely louder and shakes everything more.
Could that be because the 12 is in a sealed box would it sound better if I get that box tuned to the same frequency as the other. In the pr enclosure those subs take 600 watts RMS all the way down to 12 Hertz then you start to get mechanical noise I\'ve only done it once lol. Brian from Bay AreaPosted on 9/7/2017Hey Buck, fantastic article! I can wait to try all this stuff out next week.Couple things:When you\'re determining your HU\'s max clean volume, your gains at that point are at the minimum, right? If you were to have the gain somewhere else but still on the lower end, (say 10% or 20%), would the distortion point on the HU vary in any way?Also, if I want to leave some room to play with for my subs, I\'m assuming I should set the HU\'s sub control to its max or at least whatever number I want to use as my max when setting the gain, correct?And lastly, which is better? Running two 500 RMS subs at 4 Ohms with an amp that puts out a max of 1100 at 4 Ohms, or the same two subs at 2 Ohms where the same amp puts out 2000 at 2 Ohms? Is the amp working harder in the first scenario vs the second?Thanks!.
Buck Pomerantz from CrutchfieldPosted on 5/3/2017Cody, The misuse of low-pas filters (HPF) and bass boosts lead to the destruction of many subwoofers. Both are equalizers used to optimize the tone of the bass sound.
A low-pass filter gets engaged to remove the high-frequency notes you don\'t want the sub to play. Turning it \'all the way up\' is not the proper way to set it.
Check out for that. A bass boost gets engaged when you want to emphasize the lowest bass notes, around the low E of a bass guitar or piano. If you like the tone when using a bass boost, you must readjust the amp\'s gain control to compensate for the boost in over-all volume and ensure that no dangerous distortion ever plays.
Achieving full power in an amplifier depends on setting the gain correctly, not on the tone of the bass signal. Cody from Scott AFBPosted on 5/2/2017Sir/Ma\'am,So I have an Orion Step to 122d 12\' sub rated 1500 RMS and an Orion amp 1500 RMS and i fried a sub after it was professuonally tuned.So basically to tune properly the LPF needs to be all the way up along with the volume at the proper level then adjust the gain till it clips/distorts/buzzes right?So what\'s the purpose of having bass boost? Basically I want to push all 1500 RMS or close to it but not sure you could do that without bass boost.Also, I have a yellow top batt ran to my primary and my amp ran to the yellow top so it has a standalone battery all for itself. Cory from long beachPosted on 2/14/2017I have read some tutorials stating that you should only use the scope and test tone to set the gain up to the voltage calculated by the units actual power and the 4 ohms, and not the clipping point. The difference being that the former is the manufacturers recommended limit for \'stable\' power, and though there may be headroom between that number and the clipping point (your extra found power), it was not necessarily stable there.
Do you have any insight on that?. Buck Pomerantz from CrutchfieldPosted on 9/19/2016Tendai, The gremlin\'s in your multi-meter - it\'s only accurate at 60 Hz.
And you didn\'t say what the impedance of your subs are. 20 volts AC through a 2-ohm sub, for instance, generates 200 watts RMS. Another complication that you might not be aware of is that the impedance of a speaker or sub changes with different frequencies, and its output power does as well. Trying to set amp gain using an inaccurate meter reading the voltage of different frequencies through an unknown impedance will not work very well.
If you have an oscilloscope, use that to set your amp gains, it will result in a more accurate setting. Tendai from DerbyPosted on 9/19/2016Hi again BuckThanks for that. I\'d purchased a DSO 112 O\'scope which was en route when I asked. I\'ve since hooked it up to the amp and set the gain using 1000Hz tone for the mids and 40/50 tones for the 8 inch woofers cutting the gain to about 10% before clipping.That said I then went on to check the output voltages after all had been set with lovely sine waves on the scope. Strangely channels 1 and 2 show voltages of 17.5 and 16.5 even though I set them both to high pass at the same level (180 as per mfr).Stranger still channels 3 and 4 which are for the woofers low passed at (100Hz as per Mosconi) show voltages of 20-21 without any sign of distortion.Is there a family of gremlins in the amp?.
Tendai from Derby, UKPosted on 9/10/2016Hi BuckGreat article. Still a bit confused.
I have a Mosconi 130.4 DSP amp rated at 130RMS per channel at 4 ohms or 175RMS at 2 ohms. My speakers are Gladen 201 3 way with 4x150/100 rating at 3 ohms in a BMW E60 UK spec with 2 channels being 8 inch subs and 2 channels feeding doorcard midbases plus tweeters via a crossover. I take the 100 to be the nominal rating in that? What target voltage would you recommend if I were to use a DMM? I\'ve tried setting by ear but the E60 BMW does not have a visual for the volume so it\'s difficult to tell when one has hit 3/4 volume etc etc plus the buttons can be pressed til time immemorial without one having the foggiest whether you\'ve hit the top, mid-top, somewhere-top, not-so-top etc. Buck Pomerantz from CrutchfieldPosted on 8/2/2016Kenyon, Test tones and oscilloscopes are commonly used to set gains in audio equipment - a device\'s input sensitivity to the output of a preceding device in a system.
You can download \'0-dB\' test tones for free from the internet - a web search will turn up a vast selection. After downloading, you can burn them to a CD or store them onto a thumb drive for playing later. You then use the oscilloscope to visualize the tone as a sine wave - when the sine wave distorts, it means the signal\'s clipping and the gain needs to be reduced. I can\'t think of any reason to use test tones and an oscilloscope to set an equalizer or a crossover, however. For those, people often use pink noise and an RTA (real-time analyzer).
Buck Pomerantz from CrutchfieldPosted on 4/8/2016Zack, A subwoofer voice coil presents an inductive load, not a resistive load, to an amplifier\'s output - so measuring a coil\'s DC resistance with a multimeter won\'t accurately tell you its impedance. A coil\'s impedance actually changes according to the frequency of the signal played. Using the manufacturer\'s \'nominal\' impedance rating will bring the best results. Just be sure, when setting the gain, that your source is at its highest level with no clipping and your multimeter is accurate at the frequency of the tone you use. Most meters only read accurate AC RMS voltage around 60 Hz.
(PS: producing 300 watts through a 2-ohm load takes 24.5 volts.). Zack from EulessPosted on 4/8/2016I plan on setting my gain using a multimeter and calculating the max volts I should see for my sub. The reason is that I have a 12\' DVC sub wired in parallel that can handle 300 watts RMS, but the Alpine amp powering it can put out 500 watts RMS in 2-ohm mode. So I need to calculate how many volts 300 watts RMS is, then set the gain to that level.In doing my math, should I first test the positive/negative speaker lead to the sub to get the exact ohms for my calculation? Or is just going with 2-ohms okay? I\'m just concerned that different subs/speaker runs may introduce resistance variation, and I\'m trying to be accurate.
Ken Lacy from BaxterPosted on 8/24/2015Please help? I have installed a Pyle 5 channel amp 6800 watts into a chevy cruze. Powering an alpine 12\' sub rated for 1000 rms.
Power from Batt measures 14.2 at the amp. Ground is good from the amp to the frame. 17ft rca\'s from the stock head unit with a pac AAGM-44 adapter to give me the rca outputs. Everything is brand new. All settings on hu and amp set to minimum or 0 - volume at 75%. I play the 50hz sounds and my multimeter starts at 6 volts and i turn the gain all the way up and the highest voltage i get is 44. I have two other gain adjusters for the other 4 channels and the highest reading i get on either of them is 42.
My 2 ohm sub calls for 48 watts. Everything I read from others doing it, they can get the readings up over 60 watts and gain not even turned up all the way.Any ideas why I am getting less than normal wattage readings?.
The audio test tones below are available for free download and use in your projects. Select the tone you wish to download and click the corresponding format of your choice (or right-click and select \'Save link as..\'). All files are mono, sampled at 44100Hz, 16-bit. If you\'re not sure which tone you want, 1kHz is a safe bet.
...'>1000 Hz Test Tone(24.04.2020)Tone Frequency Duration Download: 100Hz 0:05.00 wav (0.4MB) mp3 (0.1MB) 0:30.00 wav (2.5MB) mp3 (0.5MB) 250Hz 0:05.00 wav (0.4MB) mp3 (0.1MB) 0:30.00 wav (2.5MB) mp3 (0.5MB) 440Hz 0:05.00 wav (0.4MB) mp3 (0.1MB) 0:30.00 wav (2.5MB) mp3 (0.5MB) 1kHz 0:05.00 wav (0.4MB) mp3 (0.1MB) 0:30.00 wav (2.5MB) mp3 (0.5MB) 10kHz 0:05.00 wav (0.4MB) mp3 (0.1MB) 0:30.00 wav (2.5MB) mp3 (0.5MB)
© 2020 1000 Hz Test Tone.