I use two MB450H heads into 4x 4x10 cabs I used to use a 4x10 and a 1x15 but someone blew my 1x15 up at a gig some time back. I prefer the 4x10s anyway, they sound awesome. Listen here if you want to know what they sound like (the mix is live DI from the back of the amp post pre amp and a mic...