Philipp Gerken

I tried to programm a lowpass filter, but when i route the signal after the +~ element into the delay~ nothing happens. If i route the noise~ signal directly into the delay~ the lowpass works, but you cannot control the cutoff.

Could anyone please explain or help, how to add a cutoff parameter.

programming-a-lowpass-filter-feedback-problem

depends what you trying to do, one option is to use onepole~

You can't have feedback loop like this in Max. If you want to create your own lowpass filter, 

 is the solution (you can make one sample delay with feedback with the 

 object). You could also do that in a poly~ with a vector size of 1… but I wouldn't recommend that ;-)

You can't have feedback loop like this in Max. If you want to create your own lowpass filter, gen~ is the solution (you can make one sample delay with feedback with the history object). You could also do that in a poly~ with a vector size of 1… but I wouldn't recommend that ;-)


unfortunately i only own max for live, but i would still like to create my own lowpass filter. the adding delays, like in the attached patcher seems to move the cutoff though. is there any way, to simplify this? eventually i want to create my own ladder filter.

You can try using a poly~ with a vector size of 1 (and use tapin~/tapout~ instead of delay~ since you wants feedback), but the performance aren't going to be great. Otherwise you could write a C object.

There's also some gen patcher already made (gen~.moogladder in the gen examples folder) that you can use, as well as other patches on the forums... but you won't be able to modify those examples.

thank you very much for your advise. i would really like to do the programming on my own, in order to tweak it. seems to me that investing in gen is the easiest way.

I've learned more about digital audio from building filters in gen~ than probably anything else.

Just going through this set of block diagrams and recreating them using Gen can be a very rewarding experience.

https://dl.dropboxusercontent.com/u/1042370/ClassBlockDiagrams.pdf

Is there anything accompanying that pdf? Where is it from?

I knew I recognised those diagrams and equations; after a bit of sleuthing, I found this thread, which should help unravel things:

https://cycling74.com/forums/good-sources-for-gen-dsp-code-online/

Hi Mike
I knew I recognised those diagrams and equations; after a bit of sleuthing, I found this thread, which should help unravel things:

Very useful thread with lots of advice
Brendan


programming a lowpass filter (feedback problem)?