KVR Audio

camsr · Post by **camsr** » Mon Mar 20, 2006 2:54 am

I noticed in Reason the RV7000 Reverb has a modulation parameter. I've also heard mentioned around here that the other high end reverbs do some kind of modulation to give them a high class sound. Well I was wondering, what is it that CAN be modulated inside a reverb? Comb Filters? Bandpass filters? Pitch shifters?

brok landers · Post by **brok landers** » Mon Mar 20, 2006 2:58 am

mostly the interpolated delays get modulated, which is done to avoid the buildup of resonances. also the sound of these modulations has a very beloved impact in general on the sound of reverbs. they sound way more artificial then (if the mod algorithm is good), but a lot of users love particular this behave ...

Kiwburger · Post by **Kiwburger** » Mon Mar 20, 2006 3:01 am

Some reverbs just have basically a chorus across the whole effect. You can chorus or vibrato reverb tails yourself with other plugins. I'm not at all convinced about this - it's more of an effect. The nicer reverb algorithmns are based around multiple delay lines, and each one can be modulated independantly so its more of a diffused effect and less like a chorus.

jobromedia · Post by **jobromedia** » Mon Mar 20, 2006 3:09 am

Ok. Speaking some more technological stuff, can whitenoise be used to modulate the delaylines?

brok landers · Post by **brok landers** » Mon Mar 20, 2006 3:12 am

you can of course use any waveform to modulate delaylines in a reverb, but whitenoise would brobably not be suitable, as the result would be more noised than you want to ...

jobromedia · Post by **jobromedia** » Mon Mar 20, 2006 3:42 am

I'm trying to use noise, and it works ok, just have to use very low levels of it to avoid making it noisy.

Benedict · Post by **Benedict** » Mon Mar 20, 2006 3:51 am

Noise in very small amount is a very nice mod source as it is random.

Try: get a sample of white noise, pitch it down a way to slow it down and then use it as a mod source for a random wander.

jobromedia · Post by **jobromedia** » Mon Mar 20, 2006 4:11 am

Hmmmm. Can a regular lowpass filter do the slowdown?

camsr · Post by **camsr** » Mon Mar 20, 2006 4:32 am

thats works too, i suppose.

sambean · Post by **sambean** » Mon Mar 20, 2006 4:48 am

jobromedia wrote:Hmmmm. Can a regular lowpass filter do the slowdown?

You could use a leaky integrator, in effect a sort of lowpass filter..

ie.

mod_new = (mod_old + step*rand)*0.99;
delay = length + mod;

where rand is between -1 and 1..

This way you never change the delay length by more than 'step' in one sample period. You can adjust this and the 0.99 'leak' parameter to get different rates of modulation.

What do reverbs have to modulate?