I've got an '87 300ZX (hatchback) w/ a Polk DB10 in one of the sealed hatchback Q-Logic boxes from Crutchfield a few years ago. It hardly plays any mid-upper bass and then will sound boomy and play loud for low bass. Supposedly if I remember, this box was supposed to be a good match. I can measure it when I get home. Should I have gotten an 8" instead? It's running on half of a Soundstream 500 amp, bridged.