deafdoorknob, could you tell me more in details what is the difference between T1(mk1 or mk2) and DT1770?
I mostly spent time listening to the DT1770, and a show is possibly the worse place to hold judgement on open cans. That said, with the naim cd5 as its source and powered by beyer's own desktop amps, the T1 G2 is more open sounding and has better depth-imaging than either the T1s or DT1770.
DT1770 is more forward and muscular out of all three, and tighter and more controlled than the DT770. the mids are more present but everything is clean, none the smearing I heard on the DT770 80, DT770 32 is better than the 80 in this regard as well.
Personally, I would call T1 both version to be bright but clean phones whereas I would consider the DT1770 to be a forward but clean. the solidity of its sub bass had to be heard to be believed to tell you the truth. sythn notes of around 17-25 Hz were reproduced cleanly but viscerally in a way that amazed me. and no it's not boomy.
T1 G2 has more flesh than the T1 but it's still a T1 not something completely different. Bass still has great texture but with SLIGHT added weight.
As a reference, in terms of sub bass, only the DT1770, T5p and DT770 30 reproduced it in full, the DT770 80 sounded less clean and the T7p attenuated by a fair margin.
I'll preface this by saying I am neither a Beyerdynamic fan nor a basshead, but i am currently planning for a more extensive audition of the DT1770. Like I said, I auditioned 20 or so headphones over a few hours at the show, but I returned to the DT1770 on 3 occasions and the longest being around 35 minutes of uninterrupted listening, longer than all the other headphones combined.
I can't say that it's the most neutral because neutrality is a somewhat loaded term imho but it is definitely full range and least fatiguing professional headphones I have heard.