Edited by music_4321 - 8/11/13 at 10:38am
Those who appreciate a solid midrange should seriously consider the SD2s; honestly, these IEMs have some of the best mids I've heard; The midrange is a frequency that isn't easy to get right.
I need to stress this again: the SD2s are not bass-light; my ears tell me the bass on the SD2s is done very right, with the right amount of upper & mid-bass 'energy' to make the midrange sound as good as it does.
I could do with a bit more sparkle up top, yes, but the SD2 manages to not sound muffled or dark, but it will lack that air and sometimes that accurate sound of cymbals, triangles, etc. that more treble energy usually brings to the table. But, such accurate rendering, unless listened to at low to moderate volume levels, can often get fatiguing.
Now, this isn't exactly a German version of the UM3X or W4—but, from memory, it shares more with the latter though the SD2's midrange is more convincing, clearer, better defined— and it has absolutely nothing to do with the SM3, an IEM I found to be a sonic mess. The rather subdued treble of the SD2s is what also helps make this IEM a pretty good all-rounder, particularly being very forgiving of bright recordings (unfortunately, these days there are perhaps too many of those floating around, particularly in pop, rock & metal).
I had mentioned the SD2s had a somewhat intimate presentation, and while this is true, these dual-BA IEMs sound reasonably spacious. In all honesty, perhaps my previous description had more to do with the fact I've been using some of the most open-sounding phones out there for quite some time (HD800, K3003, KAEDE, PF IX & 1601SS), so I think my "somewhat intimate" description was not as inaccurate, specially considering this is a sealed BA-based IEM — also, let's not forget the perception of soundstage also depends on the track / album we happen to be listening to.
Here's a track where I had issues with IEMs such as the 334s, UM3X & W4. The SD2s render it really, really well. Add more bass and things are spoiled / sound off. Even the percussion isn't rendered bad at all by the SD2s here: http://grooveshark.com/#!/s/Lucky/4NpRB0?src=5
And here's an example of a fairly bright-sounding track where an IEM like the SD2 can be very welcome (the good all-rounder thing): http://grooveshark.com/#!/s/Special+K/4ytFAb?src=5 —— Here, the 334s, in particular, sounded pretty spectacular; the SD2s don't sound quite as impressive, tbh, but they still sound pretty good. The thing is, I happen to have many more better-sounding albums and that's why the mighty 334s were, ultimately, not keepers. On this track the F111s sounded pretty anaemic and almost shrill.