Re: [LAU] [Rakarrack-users] multiplying signal by external synth - Linux-audio-user

21 Feb 2011

On Mon, Feb 21, 2011 at 5:32 AM, Ryan Billing &lt;ryjobil(a)gmail.com&gt; wrote:

...
  No, the preset used in the video was not in the banks.
 I just started with
 "New", then added Vocoder from "Put order in your Rack" button.  Load
one of
 the internal presets then tweak with things to get the levels correct for
 Aux level and other things.Usually output level needs to be increased quite
 a bit.

uh, I've would have sworned there was some distortion first in the effect
chain (to beef up the carrier I thought)... can't check the video right now

...
  2 ways to reduce vocoder CPU usage :
 1) Set number of bands to 16 or so (diction is less clear)
 2) Use a Downsample setting of 22050 or less in vocoder from Preferences.

thanks, I'll certainly try that.

...
  This is part of the reason I hope to use the FFT in a
new Vocoder mode.
 Probably the FFT could be used for signal analysis, then I could possibly
 apply it to 8 filter bands with adaptable frequency and resonance.

 The other thing I need to do is add a "Stereo" switch so it only processes
 the output in mono--- will cut CPU usage in half for the output filters,
 which is a big reduction ;)

 On Sun, Feb 20, 2011 at 2:09 PM, Renato &lt;rennabh(a)gmail.com&gt; wrote:

  On Sun, 20 Feb 2011 13:45:50 -0900
 Ryan Billing &lt;ryjobil(a)gmail.com&gt; wrote:

  this is nearly what an FFT vocoder does, while a
phase vocoder is
 more in line with this.

 You would window both signals, convolve via FFT, then iFFT to
 transform back to audio. Overlap and add...

 In my list of things to try is to do this exactly -- I think it would
 be a nice lower cpu alternative to the Vocoder, and it will be
 similar to the Vocoder with 256 or 512 bands.  Really good diction.

 The short answer is, yes this can be done, and yes it would be really
 interesting :)

 great :)

 today fiddled around first time with the vocoder and it was very
 cpu hungry (~80% in rakarrack top right, ~30% in 'htop') and causing
 lots of xruns - I wasn't on realtime kernel though so I'll give it
 another try.

 also, is the preset you used in the vocoder youtube video in one of the
 banks?

 cheers
 renato