Even before I listened to the AKG K812 headphones I knew they were pretty special. First, they're so incredibly comfortable that after a few minutes it was easy to forget I was wearing a world-class headphone. One reason for that is with the K812, you never feel like you're cut off from the outside world -- you can hear everything around you. Once I started listening to tunes, that spacious quality remained and stereo imaging was wider and more outside my head than what I get from other headphones. Closed-back designs are always 100 percent closed, but open-backs are not all equally open. The K812's uber-spacious quality is addicting, and once you get used to it, other headphones sound closed-in and claustrophobic.
The K812s have more powerful magnets than any other dynamic headphone on the market. The magnetic flux density is rated at 1.5 Tesla -- the next most powerful headphone, Beyerdynamic's remarkable T1, is 1.2 Tesla. The K812's mega magnets are credited with producing the headphone's unusually high sensitivity, so it can be used with phones and iPods, a feat rarely shared with other flagship headphones. Of course, it sounded best at home, plugged into a proper headphone amplifier.
A newly developed 53mm driver was designed just for the K812s. The headphones weigh 13.7 ounces -- a little heavier than average, but they feel lighter than that. Impedance is rated at 36 ohms. The ear pads and cable are user-replaceable. This made-in-Austria design's fit and finish are exemplary; plastic Beats look like toys by comparison.
The Audeze LCD X headphones have a warmer and richer tonal balance than the K812s; the LCD-X's sound has more weight to it. The K812s' sound is livelier, so subtle dynamic shadings and every cymbal shimmer sounds a little different from the next. The vocals on Robert Plant & Alison Krauss' "Raising Sand" CD sound more natural on the K812s, and I was more aware of their breathing and vocal phrasing. The LCD X was less immediate and present. It's a close contest, and I'm sure some listeners will prefer the LCD X for its fuller tone, but I love the K812's clarity and wide-open sound.
During the course of writing this review, I brought the K812s to a recording studio. It was a real treat to listen at a jazz session where I could quickly compare the actual sound of live musicians with their sound over the K812s. It was shocking to hear how close the headphones' sound was to the real thing. When the engineers and musicians checked out the K812s, they were blown away by the sound. I've brought other headphones to sessions, but never had that sort of reaction from the engineers before. The K812s are that good.
The AKG K812s sell for $1,499.