i was wondering if when you run subs inverted if it will mess the speakers up even though you have internal air space of box correct for those speakers?
At the most it will flatten the response of the driver(s). Also, making the space larger. So it will help at the least. I ran (3) GTO804's and the middle one was inverted. Sounded fine. Just make sure to flip the negative and positive to the inverted sub.