Beyer DT770 Pro 80 vs. Shure SRH 840 vs. Fischer FA-003

I own the DT770 Pro 80-Ohm and Brainwarz HM5 (FA-003)

The DT770 are bassy headphones, my old ears can not take then for more then 20 minutes (but it's still a nice full bass).

My HM5 are not as bassy as the DT770, which means I can wear them for much longer periods of time.

I would push the HM5 over the DT770s

Kind wished I had gotten the FA-003, so I would have the Velour ear pads,

but there is nothing really wrong with the HM5 pads.

Interesting questions.

Owned both the SRH840 and the HM5 (FA-003 equivalent).  Haven't had the pleasure of hearing the DT770 80 ohm - but briefly heard the DT770 250 ohm.  The 80's are supposed to be the bassier version of the DT770's based on what I've heard.  Purple can give you a confirm on that.

Anyway - my thoughts based on your criteria:

Best SQ - very subjective.  Depends what you like.  I personally preferred the SRH840 - it's the one closed phone I've actually been thinking about repurchasing.  It does have a mid-bass boost, but that adds to the overall tonality for me.  What I liked best is the mid-range on the Shures.  Has an overall feeling of balance - but not what I'd call 'flat'.  They were very 'alive' and 'dynamic'.  FA-003/HM5 very balanced, at times 'polite'.  DT770 (I'm talking about the 250 more than 80) fun cans - more of a U shaped EQ.

Flattest EQ - FA-003 > SRH840 > DT770

Largest S-stage - really difficult one - all closed phones, so none really have a large stage.  If anything, the FA-003 marginally over the SRH840

Most comfort - DT770 >= FA-003 > SRH840 (but I personally found all 3 quite comfortable for long use).

All 3 cans have their strengths - depends on your personal preference as far as music genre, and preferred tone go.  I'm a mid-range junkie - so the SRH840 would be my personal preference.