Wayne Parham Messages: 18758 Registered: January 2001
Illuminati (33rd Degree)
I would suggest building the four π speaker as designed. It is a tested and mature loudspeaker system.
The four π speaker is the result of hundreds of hours of R&D time, and to modify it basically throws all that design and testing out the window. It's not that the larger cabinet would not work - it would - but unless you have test equipment and a lot of time to make measurements, it might end up with ripple from standing waves and turn out to not work as well. So if it were me, I would go with the stock design.
I also suggest that you use multisubs. That's the best approach because it provides the deep bass extension as well as smoothing room modes. When using subs, a larger four π speaker doesn't give you anything. You don't need the extra extension.
So my advice is leave the four π build stock and employ multisubs.