Selon Martin Peach martinrp@vax2.concordia.ca:
julien.breval@tremplin-utc.net wrote:
Another solution is to calculate the highest partial that won't produce aliasing, in function of the fundamental. If we call F the fundamental, the k-th partial will have a frequency of F +
k*F
(if you chose another harmonicity system, you may adapt this formula). Therefore the maximum number of computable partials of the F fundamental is
the
integer part of (22050-F)/F. For F = 10 Hz, you can compute 2204 partials For F = 1000 Hz, you can only compute 21 partials The idea, here, is to limit the number of partials to the maximum (you can
evaluate this maximum in realtime, in function of the fundamental). You can
either mute the partials that outpass the limit (the most simple solution)
or
not even calculate them.
The effect of ultrasonic partials can be very audible. The sound seems to come from intermodulation distortion in the ear sensors themselves, which is causing lower frequency artefacts. Any calculation to simulate this effect (e.g. multiply together the ultrasonic partials while adding the audible ones) would perhaps add realism to the sound of higher frequency complex tones.
of course
(but I'm not looking forward to use additive synthesis for emulating other sounds)