Digital reverb has always been something of a dark
art as there is very little information publicly
available and most of the big companies releasing
reverbs are very vague about the techniques they
use. The only real example is Freeverb so I though I
would share some code for a reverb that sounds
pretty nice and is very low on CPU usage. It is
based on the figure-of-eight reverb structure
suggested by Dattarro, which uses a bank of allpass
filters to smear the phase followed by a loop of
multi tap delay lines that feedback into themselves
to create echoes. I have also added another delay
and a mutitap delay to act as predelay and early
reflections. The early reflections still need a bit
of tweaking but they do the job for the moment.
The code is written in C++ and is available under
the GPL license. It is really simple to use as it is
all contained in one header file and should be
cross-platform. There is also an example showing how
to use it in a VST plugin.
MVerb is available to download as a VST effect
plug-in for Windows PC. The source code can be
downloaded as well.