[sdiy] digital delay, was ...

[harrybissell]

Tee hee (inline)

Glen wrote:

> At 01:48 PM 9/12/03 , Harry Bissell Jr wrote:
>
> >(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
>
> "on-topic" ?
>
> Are you suggesting that our elaborate speculations for improving BBDs are
> *not* on topic?

no... suggesting my favorite quotes are off-topic (although The Subways of
Tazoo is an excellent
read and has a VERY strong tie-in to synth-diy - anyone remember the story
???)

> Anyway, one of my initial thoughts was that any errors in the compansion
> might be exaggerated in some ways by the frequency expansion stage, but
> having a narrow band signal going into the compander should help to keep
> those errors to a minimum in the first place. I'm just having trouble
> imagining why a compander, properly tuned for the signals passing through
> it, would have a negative effect on the transient response.

The trade off is always ripple vs response time.  The high frequency signals
could
have very acceptable ripple / response time... but the low frequency signals
would
have to use MUCH longer times, or have undesirable artifacts in the sound (IM

distortion)

>
>
> Perhaps it's primarily the band-splitting that worries you? Perhaps you
> think that the transients would be hard to reconstruct from multiple
> bandwidth-limited sources?

No... I think that part could be OK... you could use allpass sections to
time align the highs to match the group delay of the lows... if you could
hear
it.  OTOH add a BBD and the noise will mask just about everything :^P

> In the end, all of this speculation *really is* like creating "peas on a
> cob". It's a lot of effort to achieve something than can easily be done
> through simpler means--in this case digitally. However, where's the
> "Twilight Zone"/"Mad Scientist" DIY fun in that?  :)
>
> Here's a scary thought for you:   Somewhere, there is probably a mad
> geneticist that is secretly perfecting "peas-on-a-cob", as we speak.

Scarier yet... Father Guido Sarducci started his skit by explaining that
Gregor
Mendel (father of genetics) was a Catholic Monk... and that the Vatican was
continuing work along the same lines.  A photo of "Peas on a Cob" was
displayed
as partial proof of their success.  You must be psychic perhaps ???

H^) harry