The DT990 has considerably more bass presence than the Q701. That's one thing I will fully disagree on with Chicolom who says they somewhat comparable.
If I had to rate quantity:
DT990 (Premium): 8.5
The Q701 has more forward mids, but the DT990's mids are crystal clear, though distant in comparison. The Q701 has natual treble, while the 990's treble is extra sparkly. I felt the 32 ohm DT990's treble to be less sparkly than the 600ohm.
Overall, I'd choose the DT990 over the Q701.
The DT990's soundstage isn't as big, whereas the Q701 has a pretty large soundstage and an airier sound. The Q701 is very well balanced, with just a slight lack of bass to make it even what I'd consider natural bass. I feel the DT880 is the starting point for where bass SHOULD be, which the Q701 doesn't quite hit.
Positioning is the Q70's win for sure, but the DT990's positioning is great.
I just find the DT990 more enjoyable with everything I throw at it, while the Q701 is strictly business in comparison.
This was very helpful! Since I'm new to this sort of thing can you clarify a few things for me:
1. What is sparkly? I know people have mentioned the treble on 990's can hurt some people's ears when it comes to music, so I'm guessing sparkly is not a good thing?
2. Is there a difference between soundstage and Positioning? If I had to guess is soundstage a virtual area with it's limits being how far the sound projects, and positioning how accurately you can pinpoint where sound comes from within that area? If so I imagine sound stage probably adds a lot to immersion in gaming, by creating a realistic sense of space? How much smaller is the DT990's soundstage?
I'm kind of sold on DT990's at this point, since I value immersion over pinpoint accuracy, but before I bite the bullet I just want to make sure I understand exactly how much accuracy/soundstage/positioning I'm giving up in exchange for the extra bass.