[sdiy] digital delay, was ...

[Harry Bissell Jr]

Ahhh this is excellent !!! This is my main complaint
with the BBD in the first place... It doesn't stand
a "snowflake's chance in hell unless it has a ton of
refrigeration equipment alongside it".
(from "The Subways of Tazoo" by Colin Capp - 1965)

Or ~ In the words of Father Guido Sarducci (referring
to
'peas on a cob') its like "taking something that
tastes
bad, and making it hard to eat too...."

(on topic - I think the companders tuned for the
frequency band will not yield the correct transient
response once they are summed back together...)

H^) harry



--- Glen <mclilith at charter.net> wrote:
> At 10:24 AM 9/12/03 , Cornutt, David K wrote:
> 
> >To make it even more bizarre, do an analysis on the
> BBD device
> >to get a general idea of what its noise spectrum
> looks like.
> >Find the frequency band in which the device has the
> best S/N.
> >Then, divide the input signal up into bands, and
> pitch shift
> >them all into the optimum band and run them each
> through their
> >own channel.  On the output side, pitch shift them
> back to
> >their original frequencies and mix them back
> together.
> 
> As an simplified alternative, what if we tried this
> without splitting the
> original sound into different frequency bands? I
> mean, use pitch shifting
> to compress the frequency range of the original
> signal to fit into a small
> band of frequencies that the BBD handles best. (Make
> the original low
> frequencies higher, and the high frequencies lower.)
> Pass that through the
> BBD, and then re-expand the bandwidth of the signal
> to its original state.
> 
> You could also place a compander around the BBD
> stage. The reduced
> frequency range going through the compander should
> greatly reduce the
> amount of compander breathing and pumping artifacts.
> It should be much
> easier to tune the response time of the compander
> for a narrow band signal.
> 
> I'm not saying the single band approach would be
> better. Indeed, I think
> that a parallel approach should yield lower noise,
> and quite possibly less
> distortion as well.
> 
> I just think the single band approach might be
> simple enough for someone to
> actually get around to trying it.   :)
> 
> Now, if I only had some accurate pitch shifting
> devices...
> 
> 
> later,
> Glen
>