Sounds like a big gain issue.
And just so you know, I play my car stereo at about 30 and it maxes at 33. It's not like home audio, where you leave it low (BTW: I also have a clarion deck)

x3 with Smartass

You're wasting your amp in my opinion running all that power for rear fill and those 6x9's are likely to overpower your front stage which is just harsh. If you have to turn the gain way down on the rear, what's the point of running amped power to them?

Bridge that amp to the fronts and deck power to the rear if you ask me....

its too bad your deck doesnt have the crossovers to go active.

i just got a new deck and have my Xs active off 40 watts per channel.
Much better than the stock passive crossovers, and more fun to play with while sitting in traffic.