Halfing biquad filter response

On Dec 23, 7:35&#4294967295;am, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote:
> Nils <n.pipenbri...@cubic.org> wrote:
...
>
> > If you smear the phase of a sawtooth-wave in a way that the short
> > transient disappears it will sound different than a unphased sawtooth.
>
> I believe this is true, but it doesn't sound as different as
> it looks.

of course, with two or more loudspeakers (and channels), if some phase
change is applied to one channel, but not to another, that will mess
up localization.  but i see little reason to think that if identical
phase changes were applied to both channels, that this would affect
the perceived localization much.

however, if such a sweeping statement is applied to a single (mono)
sound source, i am not sure that this is true at all.  rapidly
*changing* phases, sure, but a static phase change, i am not very
convinced at all that we can hear it.  in this post,

 http://groups.google.com/group/comp.dsp/msg/184713978f96dd4c

i listed a short MATLAB program to create a nyquist (or below)
bandlimited square wave where the harmonic phases are slowly messed up
(slowly enough that the harmonic detuning would not be noticed).  the
waveform drastically changes shape, but, if your sound reproduction
system remains linear (so the peaks are not flattened), i doubt you
will hear any difference.

r b-j