Archive of the former Yahoo!Groups mailing list: The Yamaha AN1x Synthesizer mailing list

Is the decay on the pitch envelope the same shape as the decay on the
filter envelope?

For what it's worth I did a semi-objective test and here are the
results. The envelopes aren't different as far as I can tell with the
tools I have. However pitch sweeping the the resonant filter with
the filter envelope (subjectively) provides a very different sound
than pitch sweeping a sine wave (Edge=0) through the same pitch in
the same amount of time. This is due partly due to the signal
strength at various frequencies. The filter resonance is strong at
high filters and fades out at the low frequencies, the oscillator is
pretty consistent throughout. For an imitation of a percussive Bwap,
I found the oscillator version more interesting.

So how did I test the envelopes? Well I set up a pitch sweep (sine
wave traversing from 11,835 hertz to 335 hertz in roughly 14 seconds.
For the filter sweep, I obtained a resonant sine wave and then
traversed it from a pitch of 11,811 hertz to 335 hertz in roughly 14
seconds. (Hertz readings were obtained from a frequency analyzer.)

I put the two sweeps side by side in a visual frequency analyzer, and
try as I might I could not prove that the pitch envelope was any
steeper within the precision of the frequency analyzer's graph. Both
sweeps looked relatively exponential.

So my instincts were wrong as far as the instrument can tell. Still,
I learned two things:
- the filter is way louder at higher frequencies.
- the pitch envelope sweep is much more satisfying for short blips
and bwaps. Why? I don't know. So for plucked string sounds I'll be
using the pitch envelope to control sync or fm modulations.

Hope this is of interest to someone.

Jerry