[sdiy] Additive Synthesis - phase shifts important??

[harrybissell at wowway.com]

Hmmmm... if you remove the negative half of a (bipolar) square wave, you just
cut the amplitude in half.

If you "half-wave" rectify the signal you get the same effect

Fullwave rectification will give you DC.

The square, or pulse is a special case... other waves will not work the
same.  Triangle wave would get frequency doubled plus a DC offset. Sawtooth
would becdome a triangle wave plus a DC offset...

which has little to do with phase, anyway...

I'd agree with the people who say that static phase in additive synthesis
is not noticible, but dynamic phase shifts are

H^) harry


On Tue, 15 Jul 2008 14:58:37 +0100, cheater cheater wrote
> Hmm... then how do you call removing the negative half of the signal?
> 
> I think it's rectification. :P
> 
> Cheers
> D.
> 
> On 7/15/08, harrybissell at wowway.com <harrybissell at wowway.com> wrote:
> > Rectifying a square (or pulse)wave gives you DC...  ;^P
> >
> >  H^) harry
> >
> >
> >
> >
> >  On Mon, 14 Jul 2008 16:11:06 +0100, cheater cheater wrote
> >
> > > I'm pretty sure that even a constant phase-shift will give you a
> >  > noticable change in the timbre.
> >  >
> >  > But even then, consider the fact that the signal will overdrive
> >  > differently. Just put a square wave through a rectifier - you still
> >  > get a square wave. If you put the square wave shifted by Pi/2 (so an
> >  > 'arc sin wave') you will get something very different, that would
> >  > look more like an exponentialized trapezoid wave.
> >  >
> >  > Cheers
> >  >
> >  > On 7/14/08, Florian E. Teply <usenet at teply.info> wrote:
> >  > > Jim Patchell schrieb:
> >  > >
> >  > > > Your ear cannot tell what the phase relationships between various
> >  > > harmonics...however, your ear is very sensitive to a "change" in the
phase
> >  > > relationship.  Being able to dynamically change the phases as a
function of
> >  > > time would rate very important to me...(not sure if I am going to add
that
> >  > > capability to my additive synthesis project or not...).
> >  > > >
> >  > > >
> >  > >  Well, it's not that big a step from user-controlled constant phase
shift to
> >  > > user-controlled variable phase shifts, in the DDS sheme it would
break down
> >  > > to adding external data instead of internal (to the DDS module) data, so
> >  > > simply connecting some more wires to the outside instead of
generating that
> >  > > data on-module from knob positions, CVs or whatever.
> >  > >
> >  > >  Will probably generate some graphics on the general idea as soon as
my last
> >  > > exam is finished (thesis is due next monday)...
> >  > >
> >  > >
> >  > >  Greetings,
> >  > >  Florian
> >  > >  _______________________________________________
> >  > >  Synth-diy mailing list
> >  > >  Synth-diy at dropmix.xs4all.nl
> >  > >  http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> >  > >
> >  > _______________________________________________
> >  > Synth-diy mailing list
> >  > Synth-diy at dropmix.xs4all.nl
> >  > http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> >
> >
> >
> > Harry Bissell & Nora Abdullah 4eva
> >
> >
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy


Harry Bissell & Nora Abdullah 4eva