You are pretty close.
The width of the whole thing only needs to be the same as the mounting depth of one woofer.
The amp is 7.625" wide and 10.25" tall. Mounting depth is 3.5".
The woofer is 8.75" across. The through hole is 7.5". And the mounting depth is 5". And that is leaving a small air space for the vented poll piece to breath.
So it the side walls are 1" thick then the whole thing can be just 7" wide.
OK, stagger the woofers, thanks.
What impact will this have on the output as compared to the "H" frame?
Are there size ratios (driver/volume) that come into play?
If I wanted to do this with 12" servos what would the dimensions need to be, whatever will fit or should it be larger?
From what you have mentioned in the past I assume the more bracing the better.
Thanks,
Ed