The DEQ is 2 channel, with digital in/out. It could be used between your source and receiver, but would only eq 2 channels, and only for that source. It has both 31 band graphic, and 10 band parametric. The receiver would need pre out/main in to eq for all channels. The DCX is also 2 channel, some eq I think, and xover. Only analog in/out, so an AD and DA conversion.
Some of the better denon and yamaha receivers have built in eq for all channels. Comes with a mic and push button eq. I don't know how good it is, or if it's adjustable, also not a digital amp.
A plug in, or different software for the mac would be perfect, That would make me consider a mac for a server.
I hope someone has an answer.
Ryan