Dynamic equalization / Multi-band compression

Started by mavavilj August 16, 2015
How does one construct a dynamic eq or a multi-band compressor. E.g.
something like

The naive approach would be to have filters and then create envelopes to
control the gain of any such filter.

Then I've heard about using allpass filtered signal to mix into the "dry"
signal and perform dynamic equalization that way. However this approach
leads to the problem of in what proportions should these signals be mixed
back together, in the scenario of multiple bands.

So how is it done?
Posted through
The filter section consists of a cascade of 2nd-order iir filters.  To make them dynamic you can either use the standard equations developed by RBJ and compute the coefficients in real-time or you could explore an implementation using all pass filters which will reduce the complexity of the real-time updates. Do a google scholar search for Sanjit Mitre and you will find the appropriate references.