The
DT 990 got a "not recommended" rating by Amir.
So you might want to start by sorting the reviews here by "recommended". Also look at the frequency response curve and compare, and consider what kind of
difference you are looking for.
Comfort is also important when you're mixing for hours, so if possible go a store and try them. (It also doesn't hurt to try them for sound.)
And remember, you are listening/monitoring for accuracy, not enjoyment (as accurate as you can get with headphones). ...Although accurate reproduction of a good recording should be enjoyable!
Or perhaps more important, you need to learn what a good mix sounds like on your particular headphones) (see below).
The headphone amp shouldn't make much difference as long as it goes loud enough with your particular headphones (without clipping/distorting).
Most pros advise against using headphones as your main monitors.
Here are some excerpts I've collected:
This is from Recording Magazine by a mixing engineer:
Can I mix on headphones?
No. But in all seriousness, headphones can be a secret weapon and it really doesn’t matter what they sound like…
Over time, after constantly listening back to my work from different studios on those headphones I really started to learn them. They became sort of a compass. Wherever I went… It became a pattern for me to reference these headphones to see if what I was hearing was “right”…
I learned them, I knew them, I trusted them. It didn’t matter whether or not I loved them…
So, can you mix on headphones? Probably. I just think you really need to put some time into learning them first…
This is from Recording Magazine's "Readers Submissions" where readers send-in their recordings for evaluation:
As those of you who have followed this column for any length of time can attest, headphone mixing is one of the big no-no's around these parts. In our humble opinion, headphone mixes do not translate well in the real world, period, end of story. Other than checking for balance issues and the occasional hunting down of little details, they are tools best left for the tracking process.
This is from Floyd Tool's book, Sound Reproduction
Headphones entertain masses of people. Professionals occasionally mix on them when conditions demand it. Both rely on some connection to sound reproduction, that is, loudspeakers in rooms, because that's how stereo is intended to be heard. Stereo recordings are mixed on loudspeakers.
