---------------------------- Original Message ----------------------------

Subject: [music-dsp] Antialiased OSC

From: "Kevin Chi" <s...@finecutbodies.com>

Date: Fri, August 3, 2018 2:23 pm

To: music-dsp@music.columbia.edu



> Is there such a thing as today's standard for softSynth antialiased

> oscillators?
i think there should be, but if i were to say so, i would sound like a stuck 
record (and there will be people who disagree).

stuck record:� "wavetable ... wavetable ... wavetable ..."


> I was looking up PolyBLEP oscillators, and was wondering how it would relate

> to a 1-2 waveTables per octave based oscillator or maybe to some other

> algos.


> thanks for any ideas and recommendations in advance,
if you want, i can send you a C file to show one way it can be done.� Nigel 
Redmon also has some code online somewhere.
if your sample rate is 48 kHz and you're willing to put in a brickwall LPF at 
19 kHz, you can get away
with 2 wavetables per octave, no aliasing, and represent each surviving 
harmonic (that is below 19 kHz) perfectly.� if your sample rate is 96 kHz, then 
there is **really** no problem getting the harmonics down accurately (up to 30 
kHz) and no aliases.
even though the wavetables can be
*archived* with as few as 128 or 256 samples per wavetable (this can accurately 
represent the magnitude *and* phase of each harmonic up to the 63rd or 127th 
harmonic), i very much recommend at Program Change time, when the wavetables 
that will be used are loaded from the archive to the memory space
where you'll be rockin'-n-rollin', that these wavetables be expanded (using 
bandlimited interpolation) to 2048 or 4096 samples and then, in the oscillator 
code, you do linear interpolation in real-time synthesis.� that wavetable 
expansion at Program Change time will take a few milliseconds (big
fat hairy deal).
lemme know, i'll send you that C file no strings attached.� (it's really quite 
simple.)� and anyone listening in, i can do the same if you email me.� now this 
doesn't do the hard part of **defining** the wavetables (the C file is just the 
oscillator with
morphing).� but we can discuss how to do that here later.


r b-j� � � � � � � � � � � � �r...@audioimagination.com

"Imagination is more important than knowledge."

dupswapdrop: music-dsp mailing list

Reply via email to