Wayne Parham Messages: 18758 Registered: January 2001
Illuminati (33rd Degree)
Don't change the cabinet dimensions unless you have measuring equipment and can verify the changes made. Cabinets this size develop standing waves in the lower midrange, so dimensions and woofer and port position are important. You do not want a pressure node to be where the woofer or port are, because that would cause response ripple.
Wayne Parham Messages: 18758 Registered: January 2001
Illuminati (33rd Degree)
As long as you're comfortable with measurements and can do the design work yourself, that sounds like a fun project. You can still depend on the crossover to work as expected provided you keep the woofer/tweeter spacing the same.
As I said earlier, just pay attention to the response in the upper bass and lower midrange, because the standing waves we're worried about tend to be there. The low frequency part is pretty easy - Your job is to get box tuning right using the fundamental mode and attenuate any of the higher frequency modes.