I started out with one 11a, and when I had the itch to upgrade, I compared the 12's to a pair of 11a's bridged to mono. This bi-amp set-up was hands-down the winner. You don't get quite as much power as you do out of the 12's, but the bass depth and control improved quite a bit, and the midrange and treble were much more liquid and detailed. I've been completely delighted. I was back at my dealer the other day and auditioned the Revel Studios with the 12's (since he only has one 11a), and when I complained that the midrange sounded a bit congested, he told me I was spoiled by bi-amping. Definitely worth a try.
