[sdiy] digital delay, was ...

[Glen]

At 10:07 AM 9/12/03 , Harry Bissell Jr wrote:

>I'd think the soundcard would work much better,
>because
>you presume that any artifacts of the computer itself
>(backplane noise etc) would be injected into both
>channels in a more or less equal manner.  With the BBD
>you can only hope to remove some clock noise, not the
>usual "hiss" (uncorrelated noise)... which would not
>be
>equal in both channels.  If the his had similar
>frequency components and the noise reduction affected
>that range of frequency, it might help a little 

I think it might help more than you first imagine. My soundcard didn't have
identical noise signals in each channel at any given time either. The
technique doesn't demand identical noise signals to be present in each
channel, but each channel must have a similar (averaged) spectrum of noise.
The closer the two averaged spectras are, the more accurate and useful the
noise reduction is. It isn't like depending on the identical signals in a
balanced mic cable, to reject induced hum in the balanced line.

If I had a stereo BBD delay handy, I'd give it a try right now.
Unfortunately, it will probably be awhile before I would have the time to
build something just to test out this idea.


later,
Glen Berry