Hey guys,
I've got an SWR-1043D in a custom cubby box for my Jeep. It's sealed and roughly 0.8ft^3. I'm running the sub at 900w from a Hifonics BRZ1200.1D. I'm looking for an all around upgrade but don't really want to change the box if I don't have to. I was thinking of building a second box for another sub, but I'm not sure how I could best upgrade here. Any help would be sweet.

The box looks like this. I'd rather not ditch it since I like the cargo space it preserves.