I want to compute the amount of noise over a comm system by analyzing
an input WAV and output WAV. What is the best way to do this?

I tried subtracting one from the other, but it didn't go very well.
For instance, even if they're just 1 millisecond mis-aligned, you don't
get anything like noise when subtracting.

Is there a way to take the absolute value of a WAV in most audio
editors?

mike7411wrote ...
I want to compute the amount of noise over a comm system by analyzing
an input WAV and output WAV. What is the best way to do this?

I tried subtracting one from the other, but it didn't go very well.
For instance, even if they're just 1 millisecond mis-aligned, you
don't
get anything like noise when subtracting.

Appears you need to put more effort into calibrating your
system before you can depend on simple subtraction to
reveal the noise/distortion.

Is there a way to take the absolute value of a WAV in most audio
editors?

Maybe you need to define what you mean by "absolute value
of a WAV"?

wrote in message
oups.com...

I want to compute the amount of noise over a comm system by analyzing
an input WAV and output WAV.


** Does your "comm system" send the WAV as data or an analogue signal ?


BTW

Please click on "Options" before replying and then include some context and
the other poster's names.



........ Phil

wrote:
I want to compute the amount of noise over a comm system by analyzing
an input WAV and output WAV. What is the best way to do this?

I tried subtracting one from the other, but it didn't go very well.
For instance, even if they're just 1 millisecond mis-aligned, you don't
get anything like noise when subtracting.

Is there a way to take the absolute value of a WAV in most audio
editors?


For a starting point, don't send a WAV file or any other complex signal
through the system. Send a sine wave at various levels from low to high
voltage and look at the distortion components if any.

Any good hardware or software distortion analyzer can determine the
distortion without requiring a comparison of input vs output. Of course it
does help to know the amount of distortion in the test signal.

If the above is noise free, move to more complex signals such a pulses.

wrote in message
oups.com...

I want to compute the amount of noise over a comm system by analyzing
an input WAV and output WAV. What is the best way to do this?

Generate a test file and analyze it with this softwa

RMA 5.5

http://audio.rightmark.org/downloads/rmaa55.exe


I tried subtracting one from the other, but it didn't go very well.

I think you were told the reasons why in another thread.

For instance, even if they're just 1 millisecond mis-aligned, you don't
get anything like noise when subtracting.

Actually you get some noise, but you get a lot of other irrelevant stuff as
well.

Is there a way to take the absolute value of a WAV in most audio
editors?

If they have a statistics function, yes. You can also usually estimate it
from the screen.