Today I got to try out the TMA studios and I compare them against the Shure 840s and the original TMA-1 with and without an amp and here is what I thought. The song I used was steve vai's "For The Love Of God" as it had everything I could reference with in one song, crowd applause, an orchestral and of course, Steve Vai's legendary guitar skills.
First, as someone has posted before me, these are NOT neutral. They have pretty loud bass which to me bled into the mids. The cans were pretty boomy compared to the shure 840s which were said to be on the warm side of neutral. Mids themselves were pretty good and a huge upgrade from the TMA-1 DJ which are less smooth and rather edgy than the Studio. Highs I felt are not strident and piercing but not crisp and felt rather dull to me. The guitar's edginess or whatever its called did not resolve as well as the Shure 840s to me. Also, crowd applause felt rather dull and less realistic than the 840s. To me, people looking for a drum headphone should probably take a listen to this but at the price, Shure 840s are a much better choice.
Whether out of a amp or driven by the ipod 4g straight out, there is very little change in the TMA-1 studio's characteristic frequency response given its high sensitivity.
Build quality wise, it is the same as the TMA-1 DJ with larger cups, it felt rather comfy with the foam pads on the head. I really dig the industrial design though.
Isolation wise, I think the Studio isolates worse than the DJ and probably the same or worse than the 840s.
In conclusion, those looking for a good studio monitor in the TMA-1 studio would be left disappointed with its treble and bass response, I felt it was kinda overpriced with the level of detail it achieved and felt those looking for a good monitor need not look further than the Shure 840(which are priced the same in Singapore).