Here’s a free multiband compressor that aims to eliminate the phase issues sometimes associated with plug-in multi-band comps.
“The traditional way to build a multi-band compressor is to split the signal into the required number of bands using cross-over filters, then run each band- through a separate compressor before mixing them back together again.”
“This approach tends to cause phase problems around the cross-over frequencies, requiring sophisticated filter designs to minimize these effects.”
“5ORCERY takes a different approach: the signal is still split into five separate bands using cross-over filters, and these feed the side-chains of five separate compressors. But the filtered signals are not mixed back together again: instead the gain modulation signals from all five compressors are matrixed into modulation signals for 4 dynamic shelving filters plus a gain stage.”
“To put it another way: while this plug-in behaves like a multi-band compressor, and allows you to solve many of the same problems, it is in actual fact a constantly changing 4-band equaliser, and when it isn’t doing anything, it really isn’t doing anything!”
“I have therefore dubbed this approach meta-multiband compression: all the benefits of a multi-band with none of the usual side effects. Use it wherever you like, on channels, sub-groups or mixes.”
Freeware (although you can make a donation if you’re so inclined) for Windows.