Youtube review: Photos: http://dalethorn.com/Photos/iPhone6sp/Headphone_Mee_Ht21_01.jpg http://dalethorn.com/Photos/Audioforge/Mee_Ht21.jpg Sources: iPhone6s+ with Oppo HA-2/FiiO K1 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 HT21 are based on direct comparisons to other headphones, particularly other very lightweight on-ear types, but also to a few premium headphones for reference. I'll describe how I relate to the HT21 (i.e., my personal tastes and how I use the headphone) only after covering all of the objective issues. The HT21 was purchased from MEE direct on 21 Feb 2016 on order #1030 for $17.59 USD. The MEE HT21, out of the box and after burn-in, sounds fine "as is", i.e. good enough for portable use without EQ of any kind. That's pretty amazing for any headphone under $200 USD, let alone this $15 headphone. How can that be? The bass for example is flat-to-warm, with no particular emphasis, so ignoring any details that are not as well represented as with the average $300 headphone, it's a small miracle. The critical analysis shows a significant emphasis around 1.6 khz, and an equally significant recess in the upper treble, and somehow they manage to balance each other out pretty well, for portable use at least. The EQ chart on my website tells the story, but it sounds much better than I'd expect, with just a tinge of that squawky on-ear sound that's common to headphones up to $200 or so. The bass does begin to lighten up some below 40 hz, but the weight and impact is still there to a large degree down to 30 hz. If the QC is good enough that all of the HT21 samples sound the same, very highly recommended. Isolation is minimal, and a very noisy environment will mask important musical details. Leakage is low, but the volume needs to be kept below audiophile levels in quiet offices and libraries, or people sitting close by will hear faint sounds coming from the headphone. The HT21 is all plastic except the steel part of the headband, it's very small and lightweight, the drivers are 38-40 mm and capable of very loud undistorted sound, the earcups fold flat and also into the headband for very small carry size, and the headband range of adjustment is 7/8 inch on each side, where my average-size head fits in the middle of that range. The non-detachable 4-ft cable is single-sided, is terminated with a standard 45-degree-angle miniplug, but looks more durable than the cable supplied with headphones like the Beyer T51p, Bose and B&W on-ears, etc. The plastic earpads are soft, but not especially squishy, so the bass seal may be compromised until the earpads warm up to the user's head - especially in cold weather. The HT21 is an ideal portable headphone in that it can be pulled off the head when not in use, and worn around the neck with the earcups pulled out and folded flat - no need for a carry case unless the user needs to stow it away. In previous reviews I've included the following music examples with comments about how the headphones sound with each track. My suggestion is instead of reading each one as an absolute unto itself, you could compare my notes here to those other reviews and see how the HT21 compares with each individual track. Note that the comments below apply to using the HT21 without any EQ or tone controls.