I'm working on adding a subwoofer to my system and have decided on an Alpine SWR-1241D to be powered by an MTX 6500D amp. My goal is to have tight, accurate, deep bass with an emphasis on sound quality. SPL is a nice secondary benefit, of course... but it is not my primary goal. The car in question is a 1998 Ford Mustang GT.
My preliminary box design is a sealed "irregular rectangle" (wedge, shorter top, longer bottom) that will fit almost flush against the rear seat area from inside the trunk. I will most likely mount the box in such a way that about 2" of space exists between the actual back of the seat and the face of the box / subwoofer so that there's little chance of the sub ever bottoming out against the seats.
The airspace that I have been using for my box calculations thus far is 1.0 ft^3 -- taking into consideration the approximate 0.128 ft^3 displacement of the sub basket and motor assembly. Total volume, therefore, is 1.128 ft^3.
What do you all think; is this enough airspace or should I go for more or less?
Alpine's specs recommend a range of .7 - 1.0 ft^3 for the sub but when I ran the T/S parameters through BlauBox (yeah... I know) it showed that 1.0 would actually provide a flatter response curve.
I'm completely open to suggestions, so fire away.