I'm amazed that people are saying the mk3s are great out of the box... they are not. I have the alcantara pads on the way, but every pad I've tried them with has not improved the sound much. They all show massive reductions in sub bass, take a look at the Innerfidelity measurements: http://cdn.innerfidelity.com/images/Fostex_T50RPMk3_Graph_CompareMk3Mk2MrSpeakersAlphaPrime.jpg
I'll post more measurements later, here are 2:
Stock (8-9 kHz is a measurement artifact):
HM5 hybrids - they are supposedly good just with these?! (8-9 kHz is a measurement artifact):
Look at those scooped out mids and bass roll off, WOW. I cannot believe some people are just applying pads to the mk3s and calling it a day. Here's my modded mk2s as a comparison:
mk2 Maul Mod - 840 pads (8-9 kHz drop is a measurement artifact):
I always suspected that the mk3s would require more modding because the driver dampening forces you to deal with that hole (http://cdn.innerfidelity.com/images/Fostex_T50RPMk3_photo_CompareDriveronBafflePlateRear.jpg), and the venting system is harder to deal with.
Based on these measurements, clearly the mk3s are going to require extensive modding to reach what I've achieved with the mk2s. Z Reviews (no offense) is out there saying you can slap some pads on the mk3s and they're good to go. That they are so good out of the box that Mr. Speakers had no need to mod them (complete nonsense obviously, Mr. Speakers has much better things to do these days). I couldn't disagree more, just look above. Just listen for f's sake.
Anyway, I couldn't understand the mk3 craze when it happened, and now I really can't that I've heard and measured them myself.