Feedback Piano Patch Help
I'm trying to create a feedback piano as a part of an upcoming installation I'm working on and I'm using max to regulate the feedback. The basic idea is that a few transducers vibrate the soundboard of an upright piano, a condenser mic picks up the resonating strings and that sound is then fed back to the transducers. Makezine.com did a great article on feedback pianos several years ago: http://makezine.com/2009/02/27/how-to-build-a-feedback-piano/
Anyways, I have two questions/issues I'm trying to solve:
I'm pretty new to max, but I have figured out how to normalize the output level to control the feedback. However, I can't seem to work out a way to detect and eliminate the frequencies that are most prominent, and right now when I run the feedback loop with the piano can only get one tone at a time. I need a way to get several different frequencies represented in the feedback loop at once. Does anyone have any tips?
Second, I know there was a feedback piano patch floating around out there for awhile, and the above article eludes to some software created by Chris Warren several years ago. Does anyone know where I could find either of these resources? I have found several older links taking me to pages that no longer exist.
I appreciate any help!
Do you use a multi-band EQ to control the feedback? You could get started with biquad~, filtergraph~, maybe cascade~...
I'm am notching out a few of the problem frequencies with what you've mentioned, but others seem to keep popping up and then limiting the sound out of the piano to that single frequency. Is there any way to have my filter adapt to the input and generate it's own coefficients?
I've had some success using fzero~ or fiddle~ to set the cutoff freq of the filters.