There is a method to know the characteristic of room accoustic using what is called "Impulse Response". With this method, using only few (like 3, very short impulse) signal, we know all the characteristic (EQ setting needed, Clarity, time delay needed, how much reflection, etc, etc...) for that room. Don't even need RTA measurement or measuring distances for time delay 
Some are selling software for this, like www.YMEC.com
Interesting part is in here.
http://www.earlevel.com/Digital Audio/Reverb.html
It contains this "The impulse response tells everything about the room."
I think this kind of measurement is suitable for audio power amplifier. Is there anything like "Impulse Response" for audio power amp, for knowing every behavior of the amp hopely can "predict" how it will sound?
This is interesting, because this kind of measurement doesn't include steady signal. It measures very short impulses, and how it reacts to it.
Something like Mr.Graham Maynard's "First Cycle"?
Some are selling software for this, like www.YMEC.com
Interesting part is in here.
http://www.earlevel.com/Digital Audio/Reverb.html
It contains this "The impulse response tells everything about the room."
I think this kind of measurement is suitable for audio power amplifier. Is there anything like "Impulse Response" for audio power amp, for knowing every behavior of the amp hopely can "predict" how it will sound?
This is interesting, because this kind of measurement doesn't include steady signal. It measures very short impulses, and how it reacts to it.
Something like Mr.Graham Maynard's "First Cycle"?
lumanauw said:There is a method to know the characteristic of room accoustic using what is called "Impulse Response". With this method, using only few (like 3, very short impulse) signal, we know all the characteristic (EQ setting needed, Clarity, time delay needed, how much reflection, etc, etc...) for that room. Don't even need RTA measurement or measuring distances for time delay
Some are selling software for this, like www.YMEC.com
Interesting part is in here.
http://www.earlevel.com/Digital Audio/Reverb.html
It contains this "The impulse response tells everything about the room."
I think this kind of measurement is suitable for audio power amplifier. Is there anything like "Impulse Response" for audio power amp, for knowing every behavior of the amp hopely can "predict" how it will sound?
I agree, but probably not "well suitable", because there is need for a little more power for testing amplifiers, if we need to "predict" with measurements "how it will sound".
Please look at some papers about shaped tone burst... this test method is more closer to real purpose of audio amplifiers.
You can find some references at our site:
http://www.bozoel.com/products/bozotest/references.html
and some (free) test signals at
http://www.bozoel.com/products/bozotest/download.html
Use only your ears, and you can find a bunch of anomalies....
if you use loudspeakers also...
If you play test tones and record it from amplifier output, you can find also more informations with simple sound editor, like cool edit pro... etc.
Best regards,
-boggy
Hi, PMA,
I just know this "Impulse Response for Room Accoustic", I don't know much about this.
But from the idea behind it, we should know how much TIM or how much intermodulation within an audio power amp just using this kind of "Impulse Response" test. I think these factors can determine how an amp will sound (compared to THD or S/Nratio or Damping Factor).
http://www.diyaudio.com/forums/showthread.php?postid=712332#post712332
I just know this "Impulse Response for Room Accoustic", I don't know much about this.
But from the idea behind it, we should know how much TIM or how much intermodulation within an audio power amp just using this kind of "Impulse Response" test. I think these factors can determine how an amp will sound (compared to THD or S/Nratio or Damping Factor).
http://www.diyaudio.com/forums/showthread.php?postid=712332#post712332
Also step response tells you everything about linear system, becase step (or Heavyside) function is an integal of impulse (Dirac's delta) and results can be easily transformed to hypotetical impulse response.
Testing with low frequency square wave should give basically same effects.
For room acoustics it is simply easier to produce an impulse than a step, for electronics otherwise.
regards
Testing with low frequency square wave should give basically same effects.
For room acoustics it is simply easier to produce an impulse than a step, for electronics otherwise.
regards
darkfenriz said:
I agree, but I think that for room acoustics you must have stimulus with some more energy and time than MLS. When you use shaped tone burst for room acoustics you can see that they excite room modes much better, also you can hear it. with MLS you only get some graph with overall system "tested" (mic, AD, DA, math, jitter, etc.)... You cannot use your hearing abilities with MLS that easy.
Also, you cannot reveal nonlinearities with MLS, you must expect that system is linear, but if isn't? We only can imagine linear systems, but we cannot have pleasure to work with it.
best regards,
-boggy
darkfenriz said:
that's accurate. In system identification, we would use either step functions or impulse functions to identify structure and parameters of a "black box". the reasoning there is that any such function will be a composite of infinite number of sine harmonics.
In reality, you have two problems with this approach:
a) the system usually isn't linear;
b) high frequency response usually isn't as important because room acoustics is of very low resonance, as darkfenriz correctly stated.
So in theory, you can just fire one "shot" and you are done.
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