spl box

I drive a 02 civic ex. I've cut the bracing behind the rear seats to squeeze in a beefy box. I'm after boomy bass: don't care so much for Sq. I'd say 15 percent sound quality 85 percent spl. I'm running two memphis 15 C3s... Hard to find specs for them so I've obtained what I could from memphis...

i want to know if this is a good box or should i just make a T-line box. I want to know what are your opinions, here are the specs, i really need hep here guys so if you can please help me i would be very grateful