Pro: a "better" tuned DT 1770; treble taken down a notch and transition mid - bass - sub bass is smoother. Con: it's delivered without the DT 1770 case.

Beyerdynamic didn't change DT 1770. I've got DT 177X GO, DT 770 Pro 32 and Custom One Pro+. DT 177X GO is louder than the other two. Not by much, but audibly louder. Sealing is good on all (not wearing glasses). Tried DT 770 Pro and Custom One Pro+ pads on DT 177X GO. No difference in "loudness".

Wired Senheiser Momentum (M2) and NAD VISO HP50 has forward bass, neutral mids and rolled off treble (HP50 less rolled off treble).

DT770 Pro line is the "studio" version. DT770 M is the drummer monitoring version, not suitable for general music listening.

Not Ori but close enough... Eikon pads without attenuators doesn't sound good at all.

Mod: please delete.

  DT770M is good for drummers using it for monitoring purposes, and nothing else. It's the worst sounding headphone from Beyerdynamic. No soundstage (mono like), no sub-bass and no treble.

  1. I still use Westone tips. Can't remember any difference (it's a long time since I used Compy P). 2. No, but it used to be (and still is) recommended.

Good news for X2 and A5-PRO owners in Scandinavia (+Finland). Philips spare part company in Sweden have the big velour ear pads for X2 and A5-PRO.   X2: left ear: https://www.reservex.se/artiklar.asp?id=65230 right ear: https://www.reservex.se/artiklar.asp?id=65231   A5-PRO...

To reduce "metal contact", I folded a post-it around the "metal bar-thingy". Bar can now move without touching the "curved metal-thingy".

          Agree with ml. I prefer the X2 for all types of popular music. I use DT880 to classic and acoustic.

  I say the opposite, X2 has more sub bass and DT990 more mid bass.

  Not entirely true:  32 ohm model was available long before LE 88 version. BD NA didn't import this model but it was available in Europe. And, some inside cup photos suggest that the "normal" 32 ohm and LE 88 isn't exactly the same. Damping material/arrangement inside the cup is different.

  2i2 is good enough to drive your DT770Pro 80. DT770Pro and M50 emphasis different parts of bass. M50(x) have a lot of mid bass, DT770Pro 80 less mid bass and more sub bass.

They are deeper than used X2 pad, but not by much...

  I've got these http://www.ebay.com/itm/Bass-Plus-Velvet-Replacement-Ear-Pads-Cushion-For-Philips-Fidelio-X2-Headphones-/261967950938 Build quality is on par with original. They're a little firmer and deeper than original (with 6 months of use). SQ didn't change much, a tad more bass.

I've got a Woox from the time X2 was released and a newer Gibson pair. They look and sound the same.

Yes, I find m9XX easier to operate with the push button volume control. Nothing more... and Mojo isn't difficult to operate, just different from what I'm used to.

  They do sound very similar. Bass sound a little warmer with the x9XX, but that could be my imagination... Biggest difference is the user interface, I struggle with Mojo, m9XX is more intuitive.

  I've got Grace Design/MD m9XX and Mojo. Both sound exceptionally good.

I have both Sound Professionals velour pads and Brainwavz hybrid. SP velour didn't change sound much at all. Hybrid made ATH-M50 very bright sounding with very little bass. Hybrid ended up on my modded T50RP(v2). Velour still used on ATH-M50.

+1 If OP want's an open headphone; HD650 or Philips Fidelio X2.

DT770 is discontinued a long time ago. I guess simond is talking about the DT770 Pro version, available impedance values; 32, 80 and 250 ohm. All of those has much more bass-level than the old DT770.

  I've been using this from V-Moda: http://v-moda.com/audio-only-cable/ It fits X2 and T50RP (v2).

No, I live close to the Swedish border and had them delivered to public post office, Strömstad (so called Poste Restante, it's a free service in Sweden).