What amp are you using?

How did you get your calcs?

200 rms is not a lot of power. I am running 400 which is adequate for me, but it certainly does not turn heads at stop lights.

phoenix gold v752 Bridged, 4 ohms: 250 watts x 1 chan.

there's a downloadable spreadsheet available listing the required rms, V, and ohms for different setups.

The sub that I have is a kicker CVR 8" dual-2ohm listed at 200rms. I'm not sure if its safe to bump it up to 250rms.

Maybe I went with the wrong choice in subwoofer...However I find it hard to accept that this aftermarket setup is weaker than the small altec lansing pc subwoofer at home.

Does tapping into either the front or rear speakers for speaker level inputs make a difference?