Hi BillH,
I'm not a fan of installing any speakers into "recessed" areas because of the adjacent boundary effects that will possibly degrade sound quality. It's a bit unclear from your question and the illustration just how recessed the speakers will be.
Axiom does make a front-ported in-cabinet M60 that's intended to be recessed into cabinets or perhaps applications like yours:
http://www.axiomaudio.com/m60-in-cabinet.html The crossover and frequency response (as well as the porting) of the in-cabinet M60 is adjusted to compensate for recessing the speaker.
Otherwise, tower speakers (and all speakers) are designed to perform at their best in free space, not tucked into cubby-holes and the like.
Regards,
Alan
