How big of box should i use for 2 15'' Bl's? (Space is NOT a limiting factor). Also i want to use 6 inch round ports tuned to 30-35 hz. how many would i need?

7.5 cuft tuned to 33 should make a solid daily setup. Will these be the new 6" round aeroports, or just PVC or the like? If its aeroports you can get away with a pair of them... although its less than our recommendations for port area, the flares help greatly vs a standard slot port. If its PVC, then probably 3 of them plus rounding over the edges as much as possible.

Thanks,

Scott