unless your 5/6 channel amp does already have its own gain controls for the sub channels

I'm assuming that's the case. A good multichannel amplifier should, for each pair of channels, have:

- Separate gain control.
- Separate adjustable crossovers.
- Preferably, the choice between high or low pass for the crossovers.

I would think that most of the newer high-end amps would have these features. Am I right, or have I just been spoiled by my recent amp purchases?

___________
Tony Fabris