Does this module process each channel individually? Or is processing applied to all channels when any one channel exceeds threshold?
The N-Channel will take the loudest signal and reduce the gain of each channel by the same amount. This is usually desirable when you do not want the phantom center channel image to shift around due to the compressor changing the gain. Even the external sidechain control version of this cell only has one input to the sidechain and the sidechain processing will change the gain of all channels.
If you use the Standard RMS compressor you have a choice of one cell that is independent. This one uses one set of controls for the sidechain but each channel is processed separately using the same settings.
I have attached two small test projects where you can easily test this behavior. Here are some screenshots as well.
N-Channel Test Program:
Independent RMS Compressor Test Program:
Both projects are zipped into this file:
ADAU1452 Compressor Test Projects.zip