I could see someone using "ethereal" to describe the HD800's massive soundstage and airy presentation which reminds me quite a bit of the Lambdas, but the similarities stop there. With the Lambdas, sound seems to just materialize out of thin air and is lacking in a sense of weight and attack. At this point e-stat peeps get angry and tell me I'm being cliche or something. ...Sorry!

The HD800's main advantage to the K812 for me is its ability to sound authoritative with an even bigger sense of space. The K812 has a very open sound, but everything just seems a little too distant at times. The biggest indicator of this for me is catching myself turning the volume up often times --- in that sense I don't think the K812 is a particularly good low volume listen, though unlike some headphones it doesn't fall apart at lower volumes necessarily. Really, I find the K812 is one of those headphones that is deceptively easy to listen to at volumes that can damage your hearing over time. I have to watch myself closely because of it.

The K812 simply doesn't have the authority or slam I've grown a little addicted to thanks to the Abyss. Perhaps I'm being a little too hard on it, as a few people chimed in after I said this on Head-Fi and said I was mistaken and that it had a great sense of impact. Or maybe they just haven't really heard what headphones can really do in that regard.

These days I'm more sensitive to edgy treble. Upper mid hardness is also something I tend to notice more readily, but I find it's less bothersome all in all. The K812 is just really agreeable for me, and I don't hear anything too problematic with regard to audible distortion or hardness.

For my listening habits these days, the K812 is something I find myself listening to more than the Abyss or HD800 anyway because it has friendly synergy with a variety of gear, and I can enjoy it out of a DAP or some other all-in-one sitting on my desk.

well, at least it sounds like it doesn't sound like the HD800, and maybe even better than the K701.

I'm an AKG fanboi but I'm "concerned" by the 3.5kHz + 7kHz humps, and the IR looks effed up. I suspect it suffers from modal breakup on the driver plate. I think if AKG just makes a few improvements that we'd see something worth the money. I'm thinking of things like stiffening up the driver's edge/perimeter, strategic damping with quality materials, angled drivers, and giving up on diffuse field modeling. The general look can stay 'cause it's shmexy.

I'd strongly advise folks to actually listen to these headphones before dismissing them as not worth the money based on some isolated measurement parameters.

If I were going to chose one pair of open headphones to live way day-to-day, these would definitely be on my short list. I think AKG knew what they were doing.

@ ship: Hey now, I said they were lacking, not completely devoid of attack.