Comparing the dynamic range of 2 signals in real time

Right... maybe the concept is that easy then... basic arithmetic. Thanks Roman, on reflection, seems like this might be pretty easy to do in Max (though I'll have to suss out the details).

I was thinking more in standard tools and techniques though (since I'd like this feature as an iOS plugin eventually). It seems like a basic dynamics function with key input is close to what I need... but that just switches the function to the key input... does not compare the signals.

I guess though, this is feeling like another vote to make Max easily ported to an iOS plugin.