The Phiaton MS-400 I purchased is the black and red version, which looks exactly like its photos when you see it up close. The build and quality look good but the cord is thin, so for portable use you need to be careful with that cord. I compared the sound of the MS-400 to the Philips Stretch headphone, because that was the closest thing I had access to which also sounds similar. I did my listening tests with an ipod
Touch 2011 version, which controls low-impedance headphones quite well.
The most obvious quality of each headphone was the very strong bass, which was boosted overall from the lower midrange down to the very low frequencies. I decided to use the "Bass Reducer" EQ setting on the iPod, because otherwise the bass was too boomy with these headphones, and I did not want to mix in the use of a headphone amp since this review applies strictly to portable use. What surprised me about the EQ setting was how the actual bass with the MS-400 was still strong and detailed, and flat as far as I could tell down to 30 hz. The bass did seem to drop off 3 or 4 db at 20 hz, so bear in mind that's with the reduced bass setting.
One more thing I need to mention is how the earpad seal affects the bass response. In my case, when I put the MS-400 on the fit was so immediate and comfortable it was like I didn't even have a headphone on. Amazing comfort and a perfect seal. But when my wife put them on there was a gap at the bottom of the earcups that we couldn't figure out how to plug, and so she did not hear the strong bass that I did. Based on her head and ear shape compared to mine, I'd guess that people with very small heads or unusual ear shapes might not get a perfect seal with the MS-400.
Comparing the midrange of the MS-400 to that of the Philips Stretch, the Stretch had a pronounced emphasis in the upper midrange which imparts an "EEEEEEEEE" (in English) effect to the sound. Since the MS-400 midrange sounded so much better, I compared it to the Sennheiser HD-800 as well. Compared to the HD-800, the MS-400 had a slight "AWWWWWW" coloration, but nothing that would offend even with a headphone costing twice as much.
The highs of the MS-400 were comparable to the Stretch and not as sparkly or clear as the HD-800, but still very smooth and detailed. The highs did not exhibit any harshness or sibilance that I could attribute to the headphone. My overall impression of the MS-400 is that it's a very good deal at the original price, and a bargain at some of the lower prices I've seen recently. The overall sound is close enough to the Sennheiser HD-800 that I can (and will) use it for home listening and not feel like I'm being deprived of anything important.
In addition to the pop music tracks listed below, which I used mainly for detecting weaknesses or other problems with the sound, I played a wide variety of genres (Jazz, Diana Krall, Bill Evans Trio; Bach organ, Biggs; Beethoven 9th, Solti CSO; Chopin, Moravec; Reggae, Marley, Tosh; Country, Haggard, Yoakam; Verdi, Domingo; Sinatra and Bennett; Punk, Germs, Fear, Sid Vicious, Social Distortion; Medieval, Madrigali, Medieval Babes; Trance, Mylene Farmer, etc.)
The following are some of the music tracks I tested with, and the main features I listened for with those tracks:
Blues Project - Caress Me Baby (piercing guitar sound, handled very well).
Cocteau Twins - Carolyn's Fingers (guitar string detail and quality, very good).
Commodores - Night Shift (bass detail, very good).
Germs - Forming (raw garage sound, very good).
Lick The Tins - Can't Help Falling In Love (tin whistle, very clear and clean).
Lou Reed - Walk On The Wild Side (bass impact and detail, very good).
REM - Radio Free Europe (drum impact, very good).
Rolling Stones - She's So Cold (bass impact and guitar sound, very good).
U2 - With Or Without You (bass very slightly boomy; high-pitched instruments/sibilants handled very well).
Van Morrison - Into The Mystic (bass, moderate).
Who - Bargain (voice trailing off: "best I ever had", good vocal harmonics).