I just got an SD-2 8" today and I want to build the box this weekend. I am going with a sealed enclosure. Specs say for sealed the airspace is .25ft^3. My question: is that the minimum space needed or the optimal space for this sub? If it's the minimal, will bigger = better? If so, how much more space should I consider. The sub will be getting about 625w RMS.

Also, will box shape matter? Wedge vs. rectangle vs. cube?