Tuning Electric vs. Accoustic

[Harry Bissell]

It is more likely that the culprit is the "perfect" (ok its
flamebait...) replication of waveforms by the DCO. If each DCO
(oscillator) had a slightly modified wavform, one with the same harmonic
content but differing in waveshape, then the beating would no longer
cause complete cancellation. Even the triple strung piano will differ,
as the strings will have different weights, cross sections, metallurigal
differences, and be hit at different places and with different damping
etc... (all slight effects...) After the initial strike, the strings go
out of sync with each other... but they NEVER line up so perfectly that
they cancel as well as two slowly beating DCO (or VCO) sawteetc or
square waves...

I have demonstrated (and used this) with my Alesis D4 drum machine. I
trigger this from electronic drum pads. There are two zones for "snare
drum" and I use similar sounding but non-identical samples....usually.
For effect I use the same sample, same tuning, same panning... and if
you hit them j-u-s-t right, they will flange... and at about 3 discrete
pitches depending on if they are from the same Midi event, or adjacent
Midi events... etc.
If I use two different D4's... the effect is somewhat reduced because of
amplitude and clock differences... but still there...

You could probably get rid of the beating by putting each DCO through a
separate (but similar) pitch shift algorithm, with very slight
modulation. Then the chances of the waves being identical for any length
of time are remote...

The 'resonation' idea is a good one. You would have to have a way of
"coupling" energy from one wave to another...

:^) Harry

Plinio Barraza wrote:

> Hi all:
>
> I the thread on DCO some mentioned that the
> beating resulting from slightly detuned waves in
> electronic gear (electronically mixed sound) is
> far worse than in an accoustic environment.
>
> I have experienced this, and thought that it was
> the complexity of the real world that make thin
> gs this way.
>
> I wonder if one could electronically simulate
> what happens in accoustic environments (perhaps
> some form of analog physical modeling) to soften
> the effects of beating... I guess a reverb would
> do this.  (comb filter? wth resonance)
>
> But I wonder if there is a way to make one sign
> al resonate another  (does this make any sense)
>
> Another thought:  I guess another thing that hel
> ps in accoustic instruments is that they never
> play pure tones.
>
> Ciao
>
> Plinio
>
> ---------------------------------------------
> think globally, search locally - Orientation Colombia Email.
> http://co.orientation.com/eg