Hi all! I haven't seen many mods on this headphone. It is very thin, with no real cups and a extremely lightweight chassis. It sounds great out of the box. I got a pair because of the open/closed idea, and for how portable they are- all was well until the right driver developed a buzz. I also managed to lose the closed-magnet covers in a different state far away , so I decided the time had come to open them up. while I fixed the rattle (smoothed a kink in the membrane, tightened screws, etc), I couldn't resist... -Opened up all the rear driver ports ("bass ports") skewing the signature to really, really dark but reaching really, really low... -fixed the signature by sealing them with some F13 "acoustic" pressed wool and a stiff plastic sheet I think they sound pretty (really) good, and they seal/attenuate quite well! they sound quite a bit more mellow/extend a deeper than the original closed sound.