Re: Syncing Tri~ Saw~ Rect~

Forums > MaxMSP > Syncing Tri~ Saw~ Rect~
Mar 21 2013 | 3:05 am

Hi Karaokaze,

Using a lengthy wavetable for cycle~ can drastically reduce the effects of anti-aliasing(hence, the increase of cycle~'s default internal buffer from just 512 samps before Max6 to a good-sized 16K samps now).

A longer wavetable will reduce interpolation noise, but it will not reduce aliasing. Essentially, aliasing arises when you skip through the wavetable too fast, so increasing the length doesn't help.

The only problem is what Terry wrote originally about discontinuities. These discontinuities can happen when you change frequency because the phasor~ will tell those objects to reset their oscillators somewhere in the middle of their previous waveform-cycles(whose traversal began before the frequency change).

I am not sure the phasor~ arrangement I had in the first patch I posted behaves as you suggest when the frequency changes (unless I misunderstand what you're saying). I've attached a patch that randomly changes the frequency of a phasor~ and the saw~ that is acting as its sync-trigger. If you record a bit of this and examine the points the frequency changes (I just zoomed in using Audacity), there are no discontinuities in the waveform. You get discontinuities in the slope of the waveform (as in the attached image), but you never get the phase of the waveform being abruptly reset to 0.

Unless, I'm missing something…?



  1. ScreenShot20130321at1.46.33PM.png


Subscribe to the Cycling ’74 Weekly Newsletter

Let us tell you about notable Max projects, obscure facts, and creative media artists of all kinds.

* indicates required