Colton,

Yes. When I get my amps installed, I can use the X-over in the Alpine deck or the one built into the rear channel amplifier. I'll try them both out and see what sounds better. I think I'll aim for 80 to 100 Hz. filtering.

Right now I am running full-range deck power into the back doors - but faded towards the front more. There's no tweeter in the back - only the 6.5" drivers for bass. It will do for now until "CAR STEREO FEVER" hits me (every Spring) and I finish the rest of the install.

Ah that's the same thing i'm doing too, for some reason i thought you were going to be able to set them to a certain crossover range from the deck, but it just occurred to me i actually would be able to do that without a separate crossover hooked up by setting a highpass at the deck and a low-pass at the amp :O

I'll have to wait to try tweaking with my rears when it warms up a bit though x)