The convolution techniques we’ve developed in this project are aimed at live performance and are so far mostly used for that purpose. The manner in which the filters can be continuously updated might also allow for other creative applications within convolution and filtering. As a very basic demo of how the filters sound with prerecorded sounds, we’ve done two audio examples. Do note that the updating of the filters are still realtime, it is just the source sounds playing into the filters that are prerecorded.
The source sounds are prepared as a stereo file, with sound A in the left channel and sound B in the right channel. Sound A is assembled from sounds downloaded from freesound.org , all made by user Corsica_S (files “alpha.wav”, “bravo.wav”, “charlie.wav”, “delta.wav”). Sound B is a drumloop programmed by Oeyvind Brandtsegg some time in the late 90’s.
Source sounds for the convolution demo.
Sound A is recorded as the impulse response for liveconv. The length of the filter is approx 0.5 seconds (the duration of the spoken word used as source). It is replaced approx every 5.5 seconds, manually automated to line up with when the appropriate word appears in the source. This way, the first IR contains the word “alpha”, then it is replaced after 5.5 seconds with the word “bravo”, and so on until all 4 words have been used as an IR.
Liveconv demo using above source sounds.
Sound A and sound B runs continuously through the filter. No freezing of coefficients is applied. The filter length is 23768 samples, approximately 0.74 seconds at a sample rate of 44.1 kHz.
tvconv demo using the above source sounds.