If your son wants his music that loud, then you're going in the totally wrong direction. Home audio hi-fi speakers can play only so loud. What your son needs is pro sound gear, which is engineered to play at much higher sound levels. If you're listening to it that loud, fine detail and nuance are totally lost.
To my ear, some of the very most musical pro sound loudspeakers are those sold by Bag End. Look for a pro sound dealer at their website. The amps you currently have should work fine. Pro sound gear is typically more efficient than home audio. But if he really has to have more power, then he should go to the Musician's Friend website and get one of the big pro amps they have there.
All this will cost much, much less than McIntosh and other audiophile oriented gear and do a better job for this application.
To my ear, some of the very most musical pro sound loudspeakers are those sold by Bag End. Look for a pro sound dealer at their website. The amps you currently have should work fine. Pro sound gear is typically more efficient than home audio. But if he really has to have more power, then he should go to the Musician's Friend website and get one of the big pro amps they have there.
All this will cost much, much less than McIntosh and other audiophile oriented gear and do a better job for this application.