You're right in the last video though that amp dyno's tell you nothing about an amp, unless you are strictly going for SPL where distortion doesn't matter as much. Those channels would test a cheap amp that did double rated power and say it's great, but a class AB SQ orientated amp that just hits rated and say it's a bust. This series could be a good eyeopener for people. Maybe you can get some manufacturers to send you amps to test, or some amps Sam is working on.
I would imagine that some local SQ hads will want to test what they have :) Sam is working on monster sub amps, very rarely he has a fullrange amp. But yeah, I hope this will show people that there is more than max RMS value that defines an amp.
Hello! i have big problem with car amp in my car, all amps tested to subs have this problem. Distorted output (like too noise) from zero level, Signal are clean but otput are very FAT wave. I have good electrical, with distribution block (fresh instaled) After modifying the installation (cleaned all grounds, connections, new fuses itp, and distribution block) first test quiet i hear a bass waved to louder and to the quieter. (0,5sec louder, 0,5sec quieter) and stop and quieter. Bass is weak and blowing subs much before normal amplitude distortion. Sometimes basss is better in specific frequencies (sometimes above 55hz) sometimes under 30hz, sometimes above 35hz. What is cause this problem and how to fix that? All Audio wires, subs, amps, head units, exhanched many times. Thanks!
What I would do is start verifying the signal from the source all the way to the subs. I would check the electrical RTA of each component and see where the problem starts.
You can measure anything. The principle is exactly the same. Watch my previous video where I go over the gear needed to measure. And replace the amplifier with whatever you want.
Good video! But you shouldn't use 1kHz to calibrate levels, cheap multimeters are often specified to only be accurate to their spec within 30-300Hz for AC voltages. Errors increase dramatically outside this. They're meant to be "accurate" around household line frequencies, i.e either 50 or 60Hz. Some true RMS multimeters have a good extended frequency range for accurate AC peak voltages, but you have to check the specifications
I agree with you, but the calibration is not crucial is my case as I am not after absolute numbers with maximum precission. All I need is realitive comparisons betweent my amps🙂 So even +/-1V is fine.
There are 2 multimeters in this test system. One is measuring AC Volts and the other AC Current. Even the best Fluke brand clamps and meters are only accurate from ~40-400hz. 1kHz is entirely out of range and should not be used. Evaluating amps at 1khz is a useful endeavor with 1khz being very sensitive to the human ear. Just fine tune your methods. I am entirely enjoying your content none the less. Thank you!
@@RAW-CAt THD is a total of harmonics. THD+N is lumped with noise. You can either assess harmonic distortion and noise on their own contribution or in combination as an unwanted stuff metric. In any case you can compare a straight measurement without the self loop ref and see if something changes in your results.
You're right in the last video though that amp dyno's tell you nothing about an amp, unless you are strictly going for SPL where distortion doesn't matter as much. Those channels would test a cheap amp that did double rated power and say it's great, but a class AB SQ orientated amp that just hits rated and say it's a bust.
This series could be a good eyeopener for people. Maybe you can get some manufacturers to send you amps to test, or some amps Sam is working on.
I would imagine that some local SQ hads will want to test what they have :) Sam is working on monster sub amps, very rarely he has a fullrange amp. But yeah, I hope this will show people that there is more than max RMS value that defines an amp.
Hello! i have big problem with car amp in my car, all amps tested to subs have this problem.
Distorted output (like too noise) from zero level, Signal are clean but otput are very FAT wave. I have good electrical, with distribution block (fresh instaled)
After modifying the installation (cleaned all grounds, connections, new fuses itp, and distribution block) first test quiet i hear a bass waved to louder and to the quieter. (0,5sec louder, 0,5sec quieter) and stop and quieter. Bass is weak and blowing subs much before normal amplitude distortion. Sometimes basss is better in specific frequencies (sometimes above 55hz) sometimes under 30hz, sometimes above 35hz.
What is cause this problem and how to fix that? All Audio wires, subs, amps, head units, exhanched many times.
Thanks!
What I would do is start verifying the signal from the source all the way to the subs. I would check the electrical RTA of each component and see where the problem starts.
How can you possibly connect power amplifier output to the input of your soundcard???
Using a voltage divider that attenuates the signal.
@@RAW-CAt what kind of divider?? A mere resistor divider??? Can we use potentiometer to be able to make variable attenuation?
@@jeffersonavila7275watch from 15:20 ua-cam.com/video/vmNmqa-OKHs/v-deo.htmlsi=PCL4RQkiWGWHzmDn
Can you measure stock car headunits to see their signals? If yes can you make a video about it.
You can measure anything. The principle is exactly the same. Watch my previous video where I go over the gear needed to measure. And replace the amplifier with whatever you want.
Brilliant
Does possible to do the same thing with focusrite solo?
Sure, don't see why not🙂
that stove got me thinking. how dose an hot amp perform
I might be able to test it out. Is there a difference between cold and hot amp performance👍
Now measure every Audison amp ever. Go 😂
lmao
Good video!
But you shouldn't use 1kHz to calibrate levels, cheap multimeters are often specified to only be accurate to their spec within 30-300Hz for AC voltages. Errors increase dramatically outside this. They're meant to be "accurate" around household line frequencies, i.e either 50 or 60Hz. Some true RMS multimeters have a good extended frequency range for accurate AC peak voltages, but you have to check the specifications
I agree with you, but the calibration is not crucial is my case as I am not after absolute numbers with maximum precission. All I need is realitive comparisons betweent my amps🙂 So even +/-1V is fine.
There are 2 multimeters in this test system. One is measuring AC Volts and the other AC Current.
Even the best Fluke brand clamps and meters are only accurate from ~40-400hz. 1kHz is entirely out of range and should not be used.
Evaluating amps at 1khz is a useful endeavor with 1khz being very sensitive to the human ear. Just fine tune your methods.
I am entirely enjoying your content none the less. Thank you!
How techy you are
you'll blow that Focusrite up, the max Mic input is 16dBu or 4.9V. You should be using a voltage divider for higher than rated input voltages!!
If you would have watched one video before this where I go through the physical hardware, you would see that I am using an attenuation circuit.
Is a self looped reference channel really needed when measuring THD in amps? Maybe not for performance reasons but for cal purposes?
I believe it's needed in order to measure harmonics. As THD is comprised of other things, as well noise. I just have it in order not to miss anything.
@@RAW-CAt THD is a total of harmonics. THD+N is lumped with noise. You can either assess harmonic distortion and noise on their own contribution or in combination as an unwanted stuff metric. In any case you can compare a straight measurement without the self loop ref and see if something changes in your results.