These headphones are a very good match for the crack. Very smooth and balanced although the mids are a little recessed. Not a lot, just not as forward as the A700, but I have been listening to A700 for a few months now so I'm just not used to the Beyers yet. Don't get me wrong. The Beyers are in a whole different league than the A700. I just don't have anything else to compare it to so bare with me.
The treble is butter smooth on the DT 880. I've heard people describe the DT 880 as bright, but I don't hear that at all. Not compared to the A700 which can get fatiguing very quickly. I could listen to the 880 all day. I would describe the highs as revealing... in a good way. They make good recordings sound fantastic, but bad or mediocre recordings un-listenable, but after all these are a audiophile cans made for audiophile music.
As I said the mids are a little recessed, but that could be because I'm not quite used to it yet or maybe a tube roll on the Crack is in order.
The bass is super fine on these cans. Very detailed and realistic. Not boomy at all. Just natural tight bass. Love it, love it.
Overall they are very well balanced and on good recordings they just shine.
I can't wait to get some hours on them to hear what hides under all the fantastic layers.