Youtube review: Photo: http://dalethorn.com/Photos/iPhone6sp/Headphone_First_Harmonic_Ieb6_01.jpg Sources: iPhone6s+ with Oppo HA2/Beyer A200p DAC/amps, various computers using the Audioquest Dragonfly-2/HRT Microstreamer/FiiO E17k/FiiO E07k DAC/amps. Review notes: My first impressions of the sound of the First Harmonic IEB6+Mic are based on direct comparisons to other earphones such as the RHA MA750, RHA T20, B&O H3, various Soundmagic IEMs, and headphones such as the v-moda XS, AKG K553, Philips SHP9500, etc. Adding to that are the notes I've accumulated from other prior reviews. I'll describe how I relate to the IEB6 (i.e. my personal tastes and how I use this earphone) only after covering all of the objective issues. My experience with in-ear earphones (IEM's) is limited to about a dozen different types, and the sound of those varies widely depending on the eartips used and how well they seal for bass balance etc. in the ear canals. But, I have a good sense of when I'm getting the proper seal, by pushing the earpieces in until the treble drops noticeably, then backing off until it pops back in - crude but effective. The IEB6 impresses me somewhat like the RHA models (MA350, MA750, T20) on the top end, since I find the RHA's to be rather bright, even with the best eartip fit I can get. That's also true of the B&O H3 I had, or even the outrageously expensive Final Audio FI-BA-SS. So my estimation of the IEB6 is it's a bit on the bright side for me, but of course that depends on the eartips you use and how well they seal in your ear canal. The seal has a major effect on the bass and low-end warmth, which in turn determines the overall balance. My IEB6 came with the smallest eartips installed, but I settled on the next-to-largest tips which give me a pretty good seal. The IEB6 earpieces are very small and you might not expect big sound, especially smooth sound from this IEM. However, the midrange is very smooth top to bottom, and the clarity is outstanding. Maximum clean volume is more than enough to overload any user's ears, so caution is advised - don't be fooled by the size. The IEB6 bass is hard to describe, because it's close to an ideal 'neutral' curve - i.e. users who want a stronger bass will discover that most bass-boost controls make the IEB6 bass too strong. That's all good news. The bass detail is very good, but users who want strong impacts for gaming and so on might prefer something that's designed for those purposes. There are 20 music tracks listed below that give examples of how the IEB6 performs on different genres of music, but a couple more examples here won't hurt - Markus Schulz's Mainstage has an synth that goes extremely deep with immense power. The IEB6 plays it cleanly. Back down to Earth, the Modern Jazz Tuba Project performs jazz with tubas, and the IEB6 provides sufficient deep-bass detail to make the tubas sound realistic. But the creme de la creme is the 16 hz organ pedal from the Kellogg Auditorium sounds available online - you can feel the weight or the tones, and the detail is so good that you can hear the individual 'beats' of the 16 hz tone. The IEB6 soundstage is quite good, but experienced IEM users know that a full treble is necessary for a realistic soundstage, so if you were looking for an IEM that's darker than neutral, it may be difficult or impossible to get a good soundstage from it. Isolation is excellent I think, but not near Bose-level noise canceling. Leakage is very low, but if you're going to use the IEB6 in a very quiet office or library, a person sitting right next to you might hear something faintly if your playback volume is high. Summarizing my impressions of the IEB6 - a slightly bright sound (with my eartip choice) with a very smooth and uncolored midrange, and a fairly neutral bass with the right qualities. The IEB6 cable looks good and strong for an IEM. There's a control with a mic and one button (start/stop/next/previous) on the right side. The cable length is approximately 4 ft. including the 'Y' that goes to the earpieces. The terminator is a 45-degree angled miniplug. The cable is somewhat microphonic above the 'Y' where it splits and goes to each earpiece, so I recommend keeping the included clothing clip handy and using it to keep that part of the cable from rubbing against any clothing. There are 5 total pairs of eartips - one installed and 4 other pairs of different sizes. The fabric storage bag included with the earphone will protect it in pockets or bags, as long as a crushing weight or impact isn't applied to the earphones. The comments in the music tracks listed below can be compared to other headphone reviews I've done, to get an idea of how the IEB6 plays the different music tracks listed here compared to other headphones. My suggestion is instead of reading each comment below as an absolute unto itself, you could compare these notes to other reviews as they get posted, and see how the IEB6 compares with each individual track.