Quote:
Originally Posted by ksor
I'm experimenting with my first recordings of MIDI and audio on Reaper and wants some reverb and echo effects.
I found a video on YouTube explaining the ReaVerb and I have read the manual og these effects - both the YouTube video and the manual show some "files" to access for different sounds !
Mine has no files - where are these files located ?
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First off, maybe try a simple delay like "JS: Delay/delay." Once you know how these work, you'll be better able to understand ReaVerb's convo reverb features.
"These files" are impulse responses, and they are available all over the place. You can even make your own simple ones with ReaVerb's "Add…Reverb Generator."
Conveniently, audio impulse responses are usually in WAV files and other common formats. You can even listen to them, FWIW.
It's entirely possible to completely binge on impulse response collecting. Don't worry, you'll run out of time to try them all, bathe, and return to society.
http://www.voxengo.com/impulses/
https://www.ableton.com/en/blog/conv...ir-collections
Theory: just as it is possible to sample sound, it is possible to sample the way a space (1) sounds. One method uses samples called "impulse responses" because they characterize the way a space (or other system) responds to an impulse. The basic idea is you whack something with a hammer and listen to what happens.
To sample a room - kinda hard to hit with a hammer - use a starter pistol. Put a mic in a concert hall and fire a starter pistol on stage, what you're sampling is the way the hall alters any sound from that pistol's position as heard at the mic's position.
We choose hammers and starter pistols to approximate white noise - an equal distribution of all frequencies. (2) [All the freqs we're interested in, anyway.]
Once you have this impulse response, you can play a sound through it using math called "convolution." Thus, "convo reverb."
Because of the difference in time scales, even though they both use convolution, there are differences in the implementations of reverbs and cabinet sims.
Convolution
(1) By "space" is meant a room, cave, valley, inside of corrugated pipe, guitar amp speaker cabinet, even space "inside" solids like rocks and metals [think "plate reverb"]. Yep, pretty much "whatever." Importantly (!), electronic filters can be so analyzed. There are some mathematical limitations - above all, the space or system must be *linear*, that is, no distortion. It must also be "time invariant" so if you take an IR of an "algo" reverb that's specifically and wonderfully time-variant, you'll just get a frozen version.
(2) There is another way of sampling using a "sine sweep" instead of a noise. Taken together, the input sines waves have an equal intensity of all frequencies, like white noise. Taken apart, they probe how that room responds as above, but with specific detail at each frequency. Impulse responses taken this way can also be turned into friendly WAV files to feed to ReaVerb.