I'm looking at my notes and the loudest I could get the 600 to go in my room was 110dB. That was with a 20Hz pure tone which caused significant port-chuffing and a sharp sound coming from the cabinet. The beaver helped with that sharp sound \:\) . Now remember that I have a 4,000 cubic foot A/V space and the room is open to the rest of the house via a stairway. In smaller rooms, 122 dB is likely but, like jakeman said, certainly not distortion-free.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated