A bit more of a comparison between Fostex T50RP MK3 and DT990:
- stock pads sound great and to my surprise it doesn't bother me that much that they are practically on-ear, but I can't stand the PU leather after more than an hour (too sweaty and such)
- Shure 940 velour pads are miles better, but the inner foam located between the driver and the ear was itchy and muffled the treble a little, so I cut it out. I am using "naked" driver now and find the comfort great. Ears have plenty of space to "breathe" and yet the distance to the driver didn't change much.
- the sound with Shure 940 pads is almost the same, with a tad more bass than stock pads
- I tried to use other pads laying around - AKG K240 PU leather - nothing interesting in terms of sound or comfort; AKG K240 velour pads - ok comfort, very little bass; Dekoni elite velour (from DT990) - great comfort, but practically no bass
- after a few hours I have the very same issue as with DT990 - headband is creating a hotspot on the top of my head and no matter how I position the headphones, it's just there. Strangely I don't experience this with Beyerdynamic Custom One Pro (probably tighter fit and headphones don't put all their weight on the top of my head) or Marshall monitor (different headband shape). Luckily a simple DIY leather suspension strap fixed the issue almost completely (some positions are better than others) - I am going to do the same with DT990 eventually.
- I am using equalizer settings with almost the same shape for both headphones, but Fostex T50RPs are very much enjoyable even with stock tuning and require much smaller EQ values (~3dB vs. ~10dB in treble area) to sound "right" (to my ears). I find bass better on T50RP, mids are similar and treble is more gentle on T50RP.
For me, DT990s are better only in "ear comfort" (with Dekoni elite velour pads), but otherwise I like T50RP more. I would be interested in finding really comfortable headphones which don't "need" an EQ at all, but I am not sure that they exist (or that I can afford them
).
Edit: I forgot to add that Fostex had bass distortion at 50-60Hz frequencies in the right side, after I tightened all screws it stopped and overall bass response seems to be improved as well. Not such a terrible QC as Hifiman, but Beyers have upper hand here.