Posting some impressions after several dozen hours of listening through galaxy s3 (unamped us version without wolfson dac), audio-gd sparrow, and audio-gd power strip>ref 3 reclocker>ref 1>single-ended phoenix. I have settled on using the ear hooks, silver rings, black silicon ear tips, and if I don't try to insert the iem's deep into my ears (I still get a good seal), it is super comfortable, while attempting to insert deeply or the other ear cushion things can cause me a lot of itchiness and pain, so I have to say due to nozzle width of the earphones and the shape and protrusions of the housing, it's not easy to get these earphones to be comfortable, but you do get many options to try to get the earphones to be comfortable.
My suspicion that the earphones are very source dependent is confirmed now, and I have to say, it's not only the most neutral, but also the most "unflattering" or most "unforgiving" headphone or speaker I have. Usually my headphones and speakers would always impart characteristics in coloration and soundstage which I can easily hear in whatever music I play and whatever gear I use, but the dn2000 I'd say is very neutral aside from the high frequency rolloff, and I hear so much variety in soundstages with these earphones whenever I change music or gear so that I can't figure out its own soundstage characteristic imparted to music. All I can confidently say is that the soundstage it does produce is very accurate to source and recording, whether the soundstage is huge, tiny, very well-defined, or blurry, these earphones show it.
I am only going to briefly describe what the iem sounds like with different gear, because it feels like I'm pretty much just describing the gear I have and not the earphones itself. With galaxy s3, the sound is somewhat thin, pretty decent detail, not fatiguing thanks to high frequency rolloff, can listen to a long time, very good isolation, but people look at me funny because of bright brown circular capsules sticking out of my ears. With sparrow, it sounds congested, too hot or dynamic, like too much low and mid frequency detail, speed, and timbre trying to get through with too small and undefined soundstage, fatiguing to listen at moderate to moderate high volumes, but that's something I've sometimes noticed with the sparrow, just these things are really audible with these earphones. With ref1+phoenix, the sound is very neutral, instrument placement very well-defined, attack and decay very accurate when listening to many different types of music but even though more impactful and defined at high frequencies still somewhat rolled off, nothing stands out as being wrong other than the sense that high frequencies aren't all there, no sense of strident notes, soundstage can be massive or tiny depending on recording, a lot of soundstage and ambiance definition which didn't exist in s3 and was mushed in sparrow, very true to gear and recording.
Bass is very flat all the way down to 20hz which I think is very impressive, bass detail, decay, impact, all of it seems quite good, nothing I can point out as bad about it except it may be a wee bit louder relative to mids.
High frequency is pretty good at moderate to moderate high volume, but not that satisfying at low volumes with my desktop dac/amps. High frequency rolloff may be good for the intended purpose of iem's of listening through portable devices, and it is definitely a good match with my s3, but when listening to better gear it doesn't sound or feel even across the frequencies unless volume is raised to moderate to moderate high levels, which is comfortable on galaxy s3 and phoenix, but not my sparrow. At moderate volumes I would have to say the highs are satisfactory with my phoenix, maybe not exceptionally airy, complex in timbre, or detailed, but it's there. I'd say if there's an issue with the dn2000 it would be this high freq rolloff and not particularly exceptional high frequency detail, which may turn off high freq fans, but I should reiterate, it does matches well with my galaxy s3, and I suppose portable gear is what iem's have to be designed for, and I don't try to listen for complex high frequency detail when I uses my portable gear.
Mids are definitely the best part of the earphones, and although it won't sweep you off your feet with emotion because its so darn neutral and faithfully reproduces soundstage of gear and recording, it is done with incredible naturalness, number of gradients in pitch and volume, effortlessness, and accurate expression even of small microdetail and fast transitions, whether I'm using the $0.02 dac in the s3, sparrow, or phoenix. When listening very critically to vocals, the control and speed of vocal modulations are so accurate and effortless that even though it's certainly not artificially euphonic or timbral like sony pfr-v1, it reproduces sound equally beautiful.
In a nutshell and in order of strongest points, I think the dn2000 is very neutral and faithful, letting one hear what's in gear and the recording especially in soundstaging, incredibly natural and realistic mids, flat and very good bass across the board, and rolled off highs that may be well-suited for gear with confused, strident, or energetic highs (hello cellphone), but not a particularly good match with gear with rolled off highs or sufficiently controlled/detailed highs.
In dunu dn2000 product description, they say the "DN-2000 is designed for musicians", the term they are looking for is "Reference" or "Studio", and I think these iem's certainly deserve to be called such.
