So a while back I ordered a few YAXI earpads direct from them in Japan (including their HD650 earpads which I tried on the HD58x, and unfortunately just didn't work out well in that combination as I mentioned in another thread). The most curious to me were their stPad2, beacuse of the design, but I haven't commented on them before. YAXI's first two claims are what interested me most (taken from here https://www.yaxi.jp/onlineshop/ ): 1.Hybrid design The front part of inner diameter is lined with protein leather to enhance the reflection. The back part absorbing the sound is lined with Alcantara to reduce the bass. This innovative design gives the headphone a better sound balance and a cleaner sound stage, give you the ultimate in comfort. 2.Domed sponge The domed shape reduces reflections of the direct sound before entering the ear. Long-time wearing without feeling tried. A few months of casual testing later - and comparisons to about a dozen other earpads on five different headphones - there's some truth to these claims I think. I learned a lot - going forward I won't underestimate the role of earpads, their shape, and their materials (inner and outer) have on the sound of headphones (more significant than amps, DACs, cables, etc.). In my testing, it was the Maxell MXH-MD5000 that ended up being the "best fit" I felt for these pads. It was all a bit backwards for me - I tried the stPad2 with headphones I had, generally liked what they did, but the way they tempered the bass/sub-bass wasn't exactly to my liking. I didn't have the MXH-MD5000 but noticed it on YAXI's page as being compatible, and already having a positive experience with the Maxell MXH-RF550 (a single-driver in-ear earphone that surprised me with the soundstage, comfort and overall frequency response, it convinced me that someone knew what they were doing with Maxell's premium stuff), I figured it was worth a shot (it helped that the machine-translated reviews I found from people in Japan were all positive ones on the MD5000). The MD5000 are beryllium-coated diaphragms with one of those "dual-chamber" designs, i.e. internally ported: So anyway, a little bass-heavy with the stock pads, but otherwise capable, low distortion, well-controlled, with good mids and clear highs without sibilance or very uneven peaks (that I could detect). Imaging was very good, but not extraordinary out of the box. The YAXI stPad2 really seems to work well with the MD5000 to my ear. It does a few things: - Reducing most of the bass to more sane levels. Sub-bass is still a bit elevated, but now sounds more controlled, which I have no problems with. Cleanest sub-bass I think I've heard in a headphone. - Making it easy to locate sound sources in the sound field. It's like everything is spaced out more, and somehow more distinct at the same time. HRTFs test very well. Practically speaking, I need to expend far less mental energy to isolate, track, and simultaneously follow multiple sources of sound (instruments, singers, etc.) in a given song. Upshot of reduced reflections? I guess so. - Downside is that the pads aren't that deep for my XL size head/ears. My ears fit ok, but the tips of my ears touch the solid part of the cup around the driver. I alleviate this somewhat by using some tuning foam that has a center cutout, which doesn't seem to have a big impact on the sound (presumably attenuates some of the high frequencies) but increases the comfort making longer listening possible. So I learned it's not just about a) the driver b) the cup, or c) the damping behind the driver in the cup. Sure those are important and you need those all engineered well, but the space between the driver and the ear and how the sound waves are controlled in that space by the earpad are very key, too. I've seen asymmetrical earcup designs on headphones, but I can't recall seeing asymmetrical earpad designs (other than when they're angled, which is a little different I think). I think YAXI has some really good ideas with the stPad2. I'd be curious what other people think, and if it works as well on other headphones or if I just got lucky with the combination I settled on.