Hiding woofer enclosure in attic?

I have a problem that involves the SAF coefficient of a small pair of loudspeakers mounted in my dining room. Technically these are clones of Bose jewel cubes. To be blunk...they stink...but my wife loves their small size and limited visibility. They are hung from the ceiling on short metal stems.

They'd be satisfactory in the dining room application except that unlike the Bose system they imitate they do not have an accompanying woofer module. Nor do they reproduce much below around 150 Hz.

I tried pairing them up with a cheapish JBL powered subwoofer. That we an improvement to be sure, but there was still a mid-bass hole. Also, since I had to set the sub crossover to over 100 hz imaging was blown.

Considering the dual tuned bandpass design of the Bose woofer modules I've been pondering something like that, but built into the room such that the enclosure was attic mounted and vented into the ceiling. I could make a pair. The entire solution could sound better but remain essentially hidden.

Does anyone have any experience with something similar?

My wife has rejected outright the idea of replacing the cubes with flush mounted in-ceiling speakers. I did that elsewhere in the house and she was not happy with the result.

In my home office SAF is not a consideration and I have loudspeakers both suspended on aircraft cable and supported on concrete filled stands. In the domestic portion of the house my considerations take a back seat to hers. I'm not complaining. I actually appreciate the engineering challenge presented in meeting both our goals.

Michael
 
To keep your wife happy and get good sound too, I'd say use the new FR125's discussed over in the fullrange forum. Put them in boxes of similar size to what you have and use aperiodic loading to keep them small. Mount them the same as your bose knockoffs. Then add a pair of 2 woofer IB mainfolds, one next to each speaker, and cover the manifolds with A/C grills the color of your ceiling. Tune and XO to taste and you'll get great full sound from what appears to be only tiny speakers.
 
The one pictured is a manifold for 4 15" subwoofers. A manifold for 2 12" woofers could easily use a A/C grill, not the big air return grill where your filter goes. Plus you'll get better fidelity, but if you want to port a bandpass into the room, that would be easy too, just harder to integrate with your main driver. How many high fidelity speakers have you seen that use bandpass for bass?.....none due to limited bandwidth and lower fidelity.