Vocoder carrier wave bleed

Question

I made a terrible vocoder earlier and got some help on it here:

My new implementation is much better. I'm using the band pass filter described in the document suggested on the old question. It seems to work much better, but the carrier wave is bleeding heavily into the output signal to the point where I can faintly hear some good vocoder sound effects behind the sound of the carrier wave. This bleed gets louder when the input volume is higher. Is this a common and easily fixed problem or should I give more info for you guys to help me debug this?

I'm not really sure, I can't tell from that document, but I have been messing with the bandwidths. Surprisingly, a pretty big bandwidth usually sounds best. — Void Star, Aug 04 '12 at 09:01

score 0 · Accepted Answer · answered Aug 21 '15 at 07:50

I have, since my troubles with vocoders, learned a lot about signal processing in school and gone back to revisit some of my older projects and fix them. The problem with my vocoder implementation was that I was defining bandwidths in octaves, but linearly spacing my filters. There would be more overlap in higher frequencies and less overlap in lower frequencies. I'm not sure how I got carrier bleed, perhaps a bad envelope follower, but re-implementing with better filters was the real solution.

Vocoder carrier wave bleed

1 Answers1