Eagles Nest

I want to put speakers in the ceiling of my new home. The vaulted ceiling will be 1/2" plywood underlayment w/ 5/8"x 5" maple for the finished ceiling. Does anyone know the best way to attatch the speakers? With 1 1/8 " wood to get thru, should I cut a larger hole in the plywood and attach to the Maple only or can I attach the speakers from the outside rim of the case? Help? Thanks,