Simple question

[deerwolf]

Could anybody help me wtih this? Why can't I dynamically change an argument from a single value to an array without killing the audio? I'm sure I am making a simple mistake here:

x = {arg freqs = 800; SinOsc.ar(freqs, 0, 0.5)}.play // works fine

x.set("freqs", 5000)    // pitch change is working
x.set("freqs", 4000)
x.set("freqs", 3000)

x.set("freqs",[6300, 4040, 2100].choose.postln) //select from array singly is OK...
x.set("freqs",[2000, 7000, 1200].choose.postln)
x.set("freqs",[1230, 3000, 1000].choose.postln)

//BUT....

x.set("freqs",[6000, 4000, 1000].postln) //change to array ("multi-chann expansion") kills it!

// BOOM setting new single pitch at this point blows up filter

x.free


Thanks in advance...


 

[joshp]

You can't multi-channel expand values in a SynthDef dynamically. SynthDefs are precompiled, and the number of UGens inside of them are setp. multi channel expansion is used inside a SynthDef to create more UGens... so, once the SynthDef is compiled, you can't change that.

I suggest creating a simple synthdef, then calling it multiple times if you want multiple values. OR... take a look at the Control help file to see how you can send a number of values into a SynthDef that is already able to handle a number of values.

Hope that helps,

Josh