[sdiy] Turning a fixed Filter Bank into a modulated Filter

[JH.]

I've just finished an experiment of using two Frequency Shifters to turn a
Fixed Filter Bank
into something animated, modulated.

 A drone sound from the OB-8 is sent to a first Frequency Shifter, which
shifts the audio signal up by a variable amount of Hz.

This upshifted signal is sent thru a filter bank (MAM vocoder, with a rather
thin-sounding setting with all even channels up and all odd channels down.

This filtered signal is shifted back down with a second Frequency Shifter,
by the same amount of Hz that the original signal was shifted up.

First you hear the very thin sounding unshifted signal - just the OB-8 drone
processd by the vocoder filter bank.

Then we start to modulate the Frequency Shifter with the Joystick.

http://jhaible.heim.at/matrix_fx/jh_fs_updown_demo.wav  ( 7 MByte - I tried
mp3, but it was no good)

Please note that there is no filter modulation! The filter is fixed all the
time (static formant filter) - it's the signal that is modulated!

Sorry for the rather low quality of the unmodulated sound - I just made this
experiment at 1 am after
finishing the hardware. :)

Background about this project:
http://jhaible.heim.at/matrix_fx/jh_matrix_fx.html

Let me know if you have ideas what else could be processed with this. I'll
certainly try reverb, and all
kinds of fixed filters.

JH.