Hi guys! Long story short, out of curiosity I took a bit of a risk today and decided to see what was behind the rubber silicone in the HiFiMan RE252s. Specifically, I wanted to find out if the rubber enclosed another enclosure, whether the 252 was actually ported, etc Now before you kill me for taking apart a perfectly good pair of IEMs, I did this in the hope that with the collective minds of Head Fi having a look inside, maybe there would be opportunities for modifying the original design. I bought the RE252s during the $99 sale a while back, and they really have been collecting dust in my collection for a while (quite literally - that black rubber loves dust!) amazinly because the form factor was a little uncomfortable, and of all my IEMS the RE252 was the odd one out for not doing anything particularly spectacularly. However, I do think its a really competent IEM and there is a lot of potential in that incredibly detailed and smooth 9mm driver. WIthout further ado, here are my findings: It may be a little difficult to see from these pictures, but here are the important details: The silicone rubber actually just encloses an empty area. But actually, the drivers and hard plastic enclosure are SEALED. With the silicone removed, the RE252 sounds to me more or less the same. That's right - there's no dramatic drop off in bass, apart from the decrease in total weight reducing bone conduction a little. That means that the RE252 actually just has a 9mm driver in a very small sealed chamber - this may go someway explaining its somewhat bass light sound, as there is not much air it can actually move around. Now without strain reliefs and exposed wiring, of course the earpiece is too fragile to use consistently this way. The fact remains though, that the 252 has the potential to be an extremely light and comfortable IEM with a different housing - perhaps something that the RE262 will introduce. Now, this little experiment is obviously non reversible, so now I'm at a loss as to what to do with these. I'm throwing it open to you guys to suggest any other inquiries I could be making into the little chamber, or any suggestions of how I could find a new housing for these little hermit IEMs. (Maybe I could combine this with the knowledge from some of the DIY custom housing threads that are floating around ) Or, also feel free to smack me for the part-destruction of a pretty great IEM. Your call!