Can't say on tha larger size B/A, but I doubt they will fit. They make more than one series, though, and I can't say on those. The model I used front and rear is FX-4, and the magnet is quite large. It barely fits in the rear, and compresses the vent ducting a bit in the front. Sound is a bit weak in the bass, of course, but very transparent, and can take a bit of bass boost. The larger speakers should not be necessary if your son intends using a sub.