Can anyone recommend an active monitor with sound characteristics similar to the Sennheiser HD-650s? I like the 650's liquid mids, relaxed highs, and strong but not bloated bass.

I work exclusively with solo classical piano material and my room is 12x16.

I've been considering the Dynaudio BM6A + 9S. I'd also be willing to pay for a pair of B15As, but I'm assuming the mids won't be as satisfactory with such a large woofer.

Thanks!
Paul