I built a simple reverb with max/msp and made a very simple tweak but it had quite a dramatic effect…
I’m not sure how your reverbs are structured but this idea should be simple enough to translate any way you like.
Basically… add random tiny floating point values everywhere or at least on one group of filters.
for example if you had 3 comb filters running parallel and their delay values were 5ms,10ms, and 15ms…
create a random number generator for each of them for a value between 0. and 0.003 and add that to the delay.
I know a lot of people think the reverbs sound metallic-y and this should solve that.
here’s an example… first sample is without random values and the second is WITH random values.
(for this example i used values between 0. and 0.2. there may be some decent correlation between the amount of randomness needed and the overall reverb length.)
Huge difference! Would this replace the current Reverb? Be a new device included as well? Or a slider to allow the user to set the amount of randomness used (so all old songs would load with 0 amount)?
Setting your comb filters to these values seems to be the first mistake. These values are all multiples of 5, so the delay lines will essentially collide and feedback with each other at these intervals, resulting in that unnatural ‘metallic’ or ‘ringing’ sound.
According to most information I have seen that talks about digital reverbs based on a series of comb filters, the general approach is that you should tune each comb filter to a prime number. This helps to ensure that the delays/echoes occur at different times and fall in between each other, and this creates a more natural and dense sound. So instead of 5ms, 10ms and 15ms; you might try 5ms, 11ms and 17ms.
If you apply your randomisation technique to these prime number comb filters, then I think it would sound even better
I think the randomness pushes it more in the direction you describe.
For my reverb I have a master comb delay parameter and then one other parameter for setting what number to add to each following/additional comb filter. So for the example they would both be set to 5. And then the same for the all-pass filters.
I will try this prime number idea though, thanks!
I’m also excited to try this chorus->reverb idea… thanks Mark. I never really liked this idea because I don’t think of reflective spaces as “modulating”, but it should work.
“Real” spaces do modulate (pitch shift). So adding a chorus parameter cleverly in the algorithm is pretty common practice. It’s especially useful for larger reverbs like concert halls etc. This modulation is for instance the signature sound of the old Lexicon reverbs (224, 480, pcm70) and you get a feeling it is used in pretty much every record since 1980 to more recent times…
And yes, randomization is the key for any good sounding reverb. Again lexicon was one of the first doing this extensively as soon as the hardware allowed it in the mid eighties (the lex 480 random hall and other random algorithms are classics).
Anyway… reverb is a highly subjective thing. Someone wants the most natural sounding. Others will have larger then life modulated reverbs. Others find more sterile and artificial reverbs to fit best in a mix…