Exactly, take the outputs from the Eclipse and stick them into the inputs of the Empeg. Use the gains on the amps to set your volume levels for the rear speakers and the sub. Easy and free.

If you really do want a volume control on the sub, see what I was talking about above. I thought of another thing - if you're into the bass, perhaps something like Audiocontrol's Epicenter - it is small and has a small remote volume adjustment.

Yep, on the 3g board as the same name.