The AKG K812 Professional Reference Headphone

This story originally appeared at

AKG K812 Professional Reference Headphones ($1499)
In 2005 AKG introduced the K701 to much acclaim, and joined the Sennheiser HD600 and Beyerdynamic DT 880 250 Ohm to form the triumvirate of world class dynamic headphones at the time. I prefer the HD600 with its warmer tone, but all three were, and remain, excellent headphones.

In 2009, Sennheiser introduced the HD 800 at $1500 and pushed the price and performance ceiling of dynamic headphones to a new high. In the years since, many new $1000+ headphone have entered the rarified air of ultra-high-end headphones, including: Beyerdynamic T1 ($1399); Audeze LCD2 ($1145), LCD-3 ($1945), and LCD-X ($1699); HiFiMAN HE6 ($1299); and a number of others.

The problem is, none of them are without flaw. To quote Head-Fi member Beagle from this thread:

I have not heard a +$1000 headphone that wasn't a waste of money in the long run. Or put another way, I haven't heard a +$1000 headphone that didn't have a sound that I could pretty much get for way under $1000.

Put another way, SanjiWatuski produced a document looking at measured performance of flagship cans and came to the conclusion the most don't cut the mustard, and headphones like the HiFiMAN HE-5 ($500) represent performance exceeding that of most $1000+ headphones. The title of his document: "The State of Flagships: An Under-engineered Mess"

As the curfuffle at the top raged on, AKG continued to produce a seemingly endless string of K701 variants in the K702, Q701, K702 65th Anniversary Edition, and K712. Personally, I don't have much of a problem with this—the K701 was a competitive headphone and subsequent variants did show incremental improvement. I don't think manufacturers should abandon a good product without good reason. On the other hand, lots of manufacturers were scrambling to place a product in the four-figure price bracket and it seemed AKG wasn't playing along. Lots of AKG fans in the enthusiast world clamored for a new AKG statement headphone. This last November, they got it.


Physical Characteristics
There is a lot to like about the build quality of the AKG K812 headphone.

The K812 is a full-size, open acoustic, circumaural headphone. The overall color scheme is gun-metal gray, black, and satin-finished metal. The main headband arch is two metal bands covered in a somewhat soft synthetic covering, which appear to be very durable. The headband pad is suspended under the two arches, and is leather with a breathable mesh pad. Head size adjustment is accomplished by detented adjustment slides on either side of the headband pad. The adjustments are quite firm and it's not easy to make the size adjustment while the headphones are on your head, but once in place they remain firmly so. Generally I found the headband and pad very comfortable and prefer it to the "rubber band" auto-adjusting of the K701 series.


The earpads of the AKG K812 are protein leather over memory foam and are quite unique in shape. The opening of the earpad is actually narrower than the inside of the earcup, which is very spacious—people with large ears will have no problems whatsoever with these headphones. The part of the earpad low and behind the ear has an extra large lip with the words "Sound Sealing" imprinted upon, which intends to provide a better than normal seal in the troublesome spot where skull, neck, and jawline come together in a somewhat unpredictable manner. I found this structure to work very well, and applaud AKG for this novel and practical design.


The rear of the ear capsules are acoustically open using a perforated plastic mesh on the exterior and a fabric mesh attached inside. These headphones definitely do not isolate you at all from outside noise, but that's by design so no problem there. The driver housing is a short cylinder at the rear of the ear capsules, which is attached to the headband by a gimbal assembly. AKG calls this a "cardanic hinge." Not sure I buy that, Wikipedia defines cardanic hinge essentially as a universal joint; I think the assembly on the K812 is more like a gimbal, but they're quite similar so I won't make a big stink of it. Either way, this design does work very well, properly lining up the earpads with the side of your head effortlessly.

One thing I noticed that I, very surprisingly, didn't see in any of the threads about the K812 was that it appears to use a flexible printed wire assembly (FPWA) to get the signal from the headband conductors to the earpiece and driver. If you look in the photo below you'll see a shiny thing within the red oval, that's the flat printed wire part.


I'm not a big believer in swapping cables; I think that as long as there isn't any blatant problem with a cable not much is to be gained with cable swaps. On the other hand, I do think cables can make modest differences, so have no problem with the idea of using quality cable and connections. This little bit of FPWA has me a bit worried though. Is it soldered to its end connections or just pressure fit? Is the cable through the headband normal or FPWA as well?

Since we're on the topic of cables, one thing I find to be a real bummer is that the connector on the left ear piece is only three conductor. This means that it would be very difficult to upgrade the K812 to balanced operation. I know this headphone is meant for professional applications in which this is likely not a problem, but it seems to me the enthusiast market is just as likely to have a desire for this type of headphone and, for them, this is a big problem.

I did do a little looking around and it does seem that there is a way to convert the connectors to four-pin. My best guess is that the Lemo connector on the cable is a FGG.00.303.CLAD35, and what you need is a FGG.00.304.CLAD35. Fortunately, you don't need to change the whole connector, it appears that you can just change the insert for the plug and jack. If you go to this Lemo .pdf catalog, and do a search for "FGG.00.304.YL" you'll find the listing for the insert with the female part right next to it. This is just to get you started if you want to attempt the cable change, I would need to physically check the parts to be certain I've found the right ones.

Also included in the box is a very nice "Omega" style headphone stand. Sadly no carry case is included.

In sum, I found this a very comfortable headphone; styling though somewhat utilitarian remains appealing to my geek eyes. Build quality appears very good, though there have been a few reports of failures, notably three instances of distortion developing in one ear—I'm curious if these failures have been related to the printed wire assemble connections at the earpiece—and one instance of a cracked earpiece. Physically, I like these headphones very much—sonically, it's another story all together, which I'll tell you on the next page.