The HD668B gives you a very well-balanced sound with excellent clarity, while at the same time still managing to sound musical. There are other headphones which has good balance but at the same time sound too uninvolving or lifeless; the HD668B is definitely not one of them. And the HD668B doesn’t require you to have a full-fledged high-end system to hear its potential; you can just plug it into a portable player of your choice, or even straight to your computer’s soundcard, feed it with good-quality audio files, and hear what it is capable of putting out. Or, you might want to add an amplifier in the middle of the link, which does give an improvement to the HD668B. Just for kicks, I hooked up the Lavry DA11 as a USB DAC, which fed the SPL Phonitor amplifier, and plugged the HD668B in. I then played Kings of Convenience’s “Mrs. Cold” and “Boat Behind”, and wow, Erlend Øye and Eirik Bøe’s voices didn’t sound like their voices were overlapping one on another; they sound better-separated but still in perfect unison. Alicia Keys’ unplugged version of “Unbreakable” was also a real treat to listen to; I couldn’t help smiling and giggling through the entire song while closing my eyes and pinpointing which backing vocalists are where. The setup really made the HD668B’s already-excellent acoustic imaging even better than it already is.
All in all, the HD668B is a kind of headphone that “wows” you the first time you hear it, particularly because of two things: its exceptional sound and its price tag. Compared to the Alessandro MS1i, the HD668B sounds clear, spacious, everything is well-placed, and more natural, while MS1i sounds compressed, right-on-the-face, and not as clear. The MS1i just doesn’t have the HD668B’s impressive balance, acoustic imaging, and clarity. And at a mere $30, this headphone definitely competes with those that are priced two or three times as much, in terms of price-to-performance ratio.
Albums used for the test:
Alicia Keys – Unplugged, Dave Koz – The Dance, Celine Dion – My Love: Essential Collection, Eric Clapton – Unplugged, Jamie Cullum – The Pursuit, Jason Mraz – We Sing. We Dance. We Steal Things. and Mr. A-Z, John Mayer – Where The Light Is : Live In Los Angeles and Battle Studies, Josh Groban – Closer, Kings of Convenience – Declaration of Dependence, Leona Lewis – Spirit, Mannheim Steamroller – Christmas Extraordinaire, Yanni – Tribute, VA – Transformers: The Rise Of The Fallen OST. All music are ripped to 320kbps MP3 from the original CDs.
Source: 2nd-generation iPod touch, Mac Pro with iTunes
DAC: Lavry DA11
Amplifier: SPL Phonitor
Frequency response: 10 – 30,000Hz
Acoustic design: semi-open
Driver: 50 mm, 38µ double dome, neodynium magnet
Voice coil (at 1,000Hz open circuit voltage): 56 Ohms, copper coated aluminum wire
Sensitivity: 98dB SPL, 1mW
Total harmonic distortion: <0.3% at 1KHz/1V
Maximum power: 300mW
Headband pressure: Approx. 3,5N
Net weight: 222 grams (7.95 oz)