Q701's have a very nice amount of bass. I'd say midbass is even stronger than the D7000, though the sub bass is obviously not gonna touch the D7000.
In any case, the Q701 smokes the CRAP out of the HD598 in every way other than the very mid forward tone the HD598 has, where the Q701 takes a more balanced approach and keeps the mids in line with everything else.
Great to know what my Q701's can do. My personal tastes are just a bit..you know. But on most occasions my bass needs are sated with my HFI 580, XB500, and Logitech Speakers..so the Q701's are pretty nice. But for my needs and taste in music, the bass responce isn't enough.