I received my RE272 a couple of days ago and so far I just don't know what to make of their sound. I have never been this confused. I have to say that unfortunately I really don't enjoy them much at all... and yet I haven't heard anything better. It almost feels like they are too good. Too revealing for my DAPs maybe? They have amazing clarity - like that of custom Westone ES3X or even better. They also have amazing detail, but the details are not sharp - they sound washed out. I can hear lots of information I never thought was there in my music, but it's not rich in texture and sounds kind of bland and also blurry so I can't pin point where the sounds are coming from in the soundstage. Yet on the macro level the imaging is very good - vocals and all other instruments are placed with excellent precision. It's the micro detail and lacks focus. Then again, I've only listened to the RE272 through my portable DAPs so far, mainly my rockboxed Clip and I am aware that these sources are far from hi-fi especially in regards to detail resolution. Unfortunately, my Audigy 2 ZS died recently and I don't have a decent source to plug the IEMs into.
Frequency extension high and low is fantastic, especially in the bass. The RE272 goes really, really low and with great authority. With some tips, the bass can sound a little muddy - again, this may be the issue with my low-fi sources - but is otherwise exceptional with incredible resolution, depth, speed and precision that rivals the best balanced armature IEMs or even Orthodynamics. Mids are crystal clear and sound exceptionally realistic with amazing detail and yet zero harshness, seamless transients, and great coherency, reminding me of Fostex T50RP orthodynamics. All is good, except for the blurry micro detail which unfortunately is a huge issue for me and compromises all other great qualities that these IEMs have to offer. The highs are extremely detailed and nearly perfect in quantity although slightly emphasized which can make the IEMs sound a bit too bright with some music at high volume levels. Soundstage is not big, but it sounds very realistic - there are no three blobs in the head at all with these IEMs - they sound completely transparent. There is no clear left, right and middle images - everything sounds like one whole. Like Mark wrote in his review, music just seems to come into existence through these on its own and it doesn't feel like the drivers are creating the sound.
Overall, the sound of RE272 is nothing like most other IEMs and headphones I heard. They sound very little like dynamic drivers - they are much faster, clearer and more transparent than most. They definitely rival BA drivers in clarity and speed with a similar clean, dry presentation of really good BAs, except that they are at least as fast and clear as the best of them. The closest sounding headphones to RE272 that come to my mind right now are: Westone ES3X in the bass - RE272 has a very similar character to the ES3X down there: very deep, extremely clean, dry and clear and hard hitting in an odd way without much impact but with a full, thick note; Fostex T50RP in the mids - RE272 has a very similar clarity level and similar realistic timbre that makes many vocals and other real instruments jump out with uncanny realism, but RE272 has a much higher detail resolution than T50RP IMO. The highs remind me a bit of AKG K271 - soft and refined with zero harshness and yet plenty of detail and extension, but RE272 is more detailed. The highs are very different from those on RE0, ER4 or DBA-02: RE272 sounds softer than those and yet is more detailed.