Just got two pairs of the new memory foam HM5 pads (one velour, one pleather). Haven't tested the pleathers yet (see notes, below), but the velours are excellent on the HE-500s. I compared them directly to the FocusPads (modded with a stiff foam ring inserted for extra clearance). While the FocusPads are OK (more comfortable than I recalled since the last time I used them), they were a little bright and the bass was a little anemic. The new HM5 velours correct both these problems, as well as being far more comfortable. For my ears, the sound is more balanced, at least on the initial listen. Those FocusPads will be modded for jerg's new HE-560s enhancements.
I haven't compared the HM5 velours to my DIY pads (using the Q701 pad foam as a base, angled, and covered in microsuede), but the HM5s are definitely more comfortable. I suspect the HM5s may warm up the sound a bit, as the DIYs use a relatively stiff foam, and are even more spacious.
I did try the HM5 velours on the HE-560s, but as with other pads, they are a little too big to get under the yokes. The FocusPads (both types) have a very straight outer wall that slips under the yokes nicely. The HM5s are bigger and a bit puffier on the outer wall. While it's possible to wedge them under the yokes, they don't move freely, and the fit is a bit loose and awkward. As to the sound, I still prefer my other DIY pads (using old HFM pads foam as the base, angled, and covered in microsuede) to any other pads I've tried, and that now includes the memory foam HM5 pads. They muffled the natural detail retrieval of the HE-560s. That was apparent immediately upon switching back to my favs. I don't really bother with the FocusPads on the HE-560s (been there, done that), but am really curious how jerg's new mods will play out.
Hopefully I'll be able to test the new HM5 pleathers later today. My suspicion is that the velours will win the day, and the pleathers will get the microsuede treatment. I can't sing the praises enough of that material as the covering. The velours, while nice, still have a tendency to get scratchy. It's not as bad as the old HFM velours, and they are super soft and cushioned. Thus my inclination to use the microsuede on one of those pairs. Pleather is pretty meh as a covering, so....
For the record, I'd say my ears are normal size (they don't stick out a lot, but I am 6' 5"/195 cm), but always seem large when it comes to pads. For example, the openings of the Shure Alcantara pads are way to small; they sit half on my ears. FocusPads are pretty good, and have decent depth with the foam ring inserted. These new HM5 pads have plenty of room, are not irritating, and seem to float on my head. I had to bend the headband of the HE-500s to get a bit more clamp.
I did create a crescent-shaped foam ring (folded the foam ring from the FocusPads and cut it in half, then angled the ends a bit, and trimmed to make them thinner) and inserted those into the HM5 velours. It creates a mild angle and gives a bit more clearance. Not sure I noticed a difference in sound. I did not do the back vent mod (see the jergpad modding guide), though I may do that soon. It seems to help the HE-500s. My HE-500s do have the Fuzzor and grill mods.
Mounting Fun
I was able to get full-size HiFiMAN mounting rings into the velours without incident. Not so lucky with the pleathers. I have a couple extra pairs of the mounting rings, but they seem to use slightly different plastic. The pair that worked with the velours seem a little more pliable than the other pair. The stiffer pair broke on the outer portion (not a complete break) when I was working them into the pleather pads. I also have a pair of rings in the old HM5 pads. I had trimmed the outer portion of those rings, which makes it easier to get them in, but the fit of rings+pads on the cans is a little loose. It works, but it would be better to use the full rings. Double-sided tape (photo stickies, etc.) would probably help stabilize them.