AKG K812 Reference
AKG K812 Headphones (36 Ω, 14.135 oz./400.7 g without cord, about $1,500). bigger. I got mine at B&H; Adorama and Amazon also carry them. My biggest source of support for this free website is when you use those or any of these links to approved sources when you get anything, regardless of the country in which you live. It helps me keep adding to this free website when you get your things through these links — but I receive nothing for my efforts if you buy elsewhere. Thanks for your support! Ken.
November 2014 AKG reviews Headphone Reviews Audio Reviews All Reviews
The AKG K812 are smooth, clean and clear open-back headphones with the best bass I've heard yet from AKG. Bass is solid, and not weak as it usually is from AKG who aim more for studio accuracy than home enjoyment.
These AKG K812 are possibly the most enjoyable big, open-back headphones I've ever heard. With its low impedance, the K812 is especially good for use with iPads, iPhones and iPods. The K812 is this enjoyable because it has a better combination of warmth, smoothness and better bass than other German open-back headphones.
These are for solo listening either in your studio or your easy chair, not for commuting, a cubicle or use around other people. As open headphones, they leak a lot of sound so everyone else near you is going to have to listen to them, too.
These are big and clumsy, but light weight. They have low ear pressure and they are comfortable for unlimited hours, but you can't move or walk around while wearing these because they'll fall off.
Their sound varies as moved around my head, showing us that they will sound different on different people's heads.
On my head, the K812 sound fantastic, but when compared with other headphones I find the K812 a little bit rougher. This is mostly due to a slight rise in the lower presence range around 2 kHz, at least on my head. My other favorite headphones sound smoother to me since they lack this rise, but if I'm not wasting my time comparing, the K812 sound terrific.
The AKG K812 are good for mixing and mastering because what you hear is what you've got. When you get it to sound great in the K812, it should sound great everywhere.
Unlike once-great speaker makers and everyone else who are jumping on the bandwagon and suddenly selling Chinese-made headphones with their brand stamped on them, AKG has been the real thing in studios ever since their founding right after World War II. These K812 are made in Austria. Austria has no kangaroos; Austria is just south of Germany and the birthplace of Mozart, Haydn, Schubert, Mahler, Strauss, and many more.
Anyone who's worked in radio or recording knows AKG microphones and headphones. The AKG C414 mic was seen in front of Johhny Carson and Jay Leno on NBC's Tonight Show for decades. I've been using them since the 1970s, and they've been on the scene since the 1940s.
The K812 are a very inexpensive way to get fantastic sound for a very long time to come. You'd have to spend tens or hundreds of thousands of dollars on loudspeakers and acoustic room treatments and refitments to get sound as smooth, clean, natural and revealing as these headphones give you for a tiny fraction of the price.
Oddly these are low impedance, meaning they are optimized for portable use. They really ought to be called 'iPhone Reference" headphones, which is what they are, since studio headphones should be 600 Ω to optimize the performance of studio headphone amplifiers. (Lower impedance headphones cause more amplifier distortion, and lead to more bass distortion when amplifiers have non-zero output source impedance.)
The K812 are not as sensitive as most other low-impedance headphones. With their 36 Ω impedance they go plenty loud on my iPod and iPad, but not as loud as others like the Ultrasone Edition 8, Beyer T51i or Sony MDR-V6.
AKG K812 on included stand.
Back of AKG K812 box. bigger.
Around-the-ear open-back dynamic headphones.
Two-layer voice coil.
1.5 Tesla magnet system.
Driver, AKG K812 Headphones. Bigger.
The lighter dots are actually my background shining through the transparent (presumably mylar) diaphragm.
The cushions are soft and leather-like. Their funny shape is intentional.
They go around your ear, and their insides oddly bend away from the center as they get closer to the driver.
Cables and Connectors
3 meter (10 foot) straight plastic cord.
3.5mm plug with 1/4" screw-in adapter.
Tiny LEMO connector connects to headphones.
Cable, AKG K812. bigger.
LEMO Plug, AKG K812. bigger.
5 Hz ~ 54 kHz, unqualified.
110 dB SPL at 1 V.
AKG K812 measured Impedance magnitude (Ω=V/Vr), and phase angle versus frequency. (R&S UPL; +90º is capacitive, -90º is inductive.)
Rated 36 Ω.
Measured 44 Ω, almost entirely resistive.
300 mW, which is 3.3 volts into the rated 36 Ω.
14.135 oz. (400.7 g) actual measured, without cord.
AKG specifies 13.8 oz. (390 g).
Detail, AKG K812 included stand. Bigger.
Headphones with cord.
1/4" screw-in adapter in gold.
Real fancy box, but no carry case.
Cloth-covered box inside.
November 2014: $1,500.
I don't believe in break-in, but since some people do, I ran-in my K812 with loud pink noise for a day. There was no change in sound.
The K812 are neutral, with deep natural bass and only a slight boost around 2 kHz.
The sound changes as I move it around on my head. This means these will sound genuinely different to different people, and the differences will be more than just personal preference.
I heard about the same soundstage as most other headphones. It's all in your head or an inch out — not 50 feet away.
The K812 have completely neutral bass. It's not boosted or bumped-up as in many other headphones. Headphones that boost the deep bass like the Audio-Technica ATH-M50, Velodyne vPulse or Sony MDR-V6 will have more entertaining, but less accurate, bass.
The bass of the K812 is as you want it for creating music. You can hear everything, tight and natural, and not boosted.
Everything has more bass when played louder because our ears' sensitivity to low frequencies is reduced at low levels, so, yes, played louder with a bigger amplifier you will hear more bass. That's nature, not anything unique to these headphones.
Bass is good. It's smooth, deep and natural. Recordings dripping with bass sound that way, and thin recordings sound thin.
The K812 is low-impedance (rated 36 Ω) optimized for portable use, not for professional use. This isn't the way to make a studio reference headphone; these are iPod reference headphones.
The rated 36 Ω (or measured 44 Ω) impedance helps work great plugged into an iPhone, but sadly isn't best for getting the best sound.
Higher impedance (300 Ω or 600 Ω) headphones let all headphone amplifiers work with less distortion, and also nullify any sonic defects added when the real impedance of real headphones starts to interact with non-zero output impedances of ordinary headphone amplifiers and headphone outputs.
While top-notch amplifiers like the Apple devices and the the Benchmark DAC1 HDR have zero or near zero output source impedances and won't really care, many home amplifiers have output source impedances ranging from about 50 Ω to 150 Ω, and will introduce both harmonic distortion in the bass as well as add frequency response errors.
While further discussion is beyond the scope of this review, low headphone impedance doesn't affect the headphone's performance, but it often does affect the performance of source source equipment. From a system standpoint, higher impedance headphones are best if you have the luxury of an external headphone amplifier.
These are ideal for use with Apple portables which have superb low-source-impedance output amplifiers, but I can't vouch for other brands.
For studio use and use with plug-in-the-wall headphone amplifiers and stereo receivers, these really should be 600 Ω.
The K812 work great with an iPhone, iPad, iPod, CD or SACD player.
There is plenty of sensitivity for use with any of Apple's devices with no need for an external amplifier.
I found I only had the level about halfway up with Apple's devices. I can blow my brains out from any iPod. Bravo!
These are open headphones with only a slight muffling of high-frequency sounds from outside.
As open headphones, everyone else will hear your music, too.
The big drivers mean loads of leakage.
You won't be using these on a train, bus or in your office — unless you can lock your door. Likewise, you can't use these in bed and expect anyone else to sleep.
Just like electrostatic headphones, the diaphragms are light enough that the sound changes drastically as I bring my hands near the outside of the drivers.
This is because the sound that comes out the back of the headphones bounces off my hands back into the headphones, and the overall headphone and its diaphragm are light enough that the sound goes back in and interferes with the sound.
This is good; it means the K812 is open and sonically transparent.
These are very comfortable, but fall off. They use little pressure on your head.
These are lightweight, but big, floppy and clumsy. Look up or down, and they fall off your head.
The adaptable 3.5mm plug has the usual screw threads for the 1/4" adapter. It may or may not push-in to iPods and iPhones in cases.
I'd prefer a coiled cord; the K812 has a long straight cord.
The harp has to be adjusted manually. Once adjusted, it does not move; it takes some force to adjust the clicks. You are adjusting where the floppy pad attaches to the harp.
The big headband is plastic.
The earpieces and little gimbals are metal.
It feels plasticy, since you're usually grabbing the headband.
The straight plastic cord feels the same as most $15 headphones, while the LEMO connector is very nice.
I use these with my Benchmark DAC1 HDR and my Apple devices.
You don't need an external amplifier unless you want one. Apple's devices have great output sections. I can't vouch for other brands, which probably don't have the quality of Apple. Generic MP3 players can vary all over the map, while Apple makes great stuff.
I wouldn't waste money on any different cables. If you want better sound, man-up and get better headphones like the Stax instead.
These were all driven by the Benchmark DAC1 HDR:
Compared to the Stax SR-007 Omega Mk II
This squawk from the AKG make it sound rougher than the Stax. I prefer the Stax, which sound much smoother, cleaner and more natural.
Compared to the Ultrasone Edition 8
The Ultrasone Edition 8 are smoother and less harsh.
The overall balance is similar, with the Edition 8 having more boosted bass and the K812 sounding slightly rougher.
I prefer the sound and ergonomics of the Edition 8.
Compared to the Beyerdynamic T51i
The Beyerdynamic T51i is much more sensitive and smoother. Overall balance is very similar, but the AKG are harsher and less smooth.
The T51i sound the same as they're moved around my head, while the K812 sound very different with on-head position.
The Beyerdynamics bring me directly into the concert hall, while the AKG sound more like just a recording. The T51i are warmer than the slightly brighter AKG. The AKG are brighter and clearer which some might prefer, but with these Beyer T 51i, I'm actually at the concert instead of just listening to it over headphones.
The Beyers are smoother, while the AKG are brighter and a bit more forward. I enjoy the sound from the Beyers more than these AKGs which cost five times as much.
The K812 have no remote control, no built-in mic and no travel case as do the T51i.
The all-metal T51i feel much better made, while the K812 makes do with a plastic harp.
The T51i is made in Germany, the K812 in Austria.
The T51i are much more comfortable to use and wear while moving around, isolate from external noise, and and have no sound leakage to annoy others.
The K812 are strictly for use by yourself while not moving around, while I love using the T51i anywhere and everywhere. While the K812 are more accurate for mixing, mastering and quality control, I enjoy the sound of the T51i more. The T51i brings me into the concert hall in a way that the drier K812 do not.
The AKG K812 are the most enjoyable-sounding full-sized open-back headphones I've used. Since they have an unusually low impedance for full-sized headphones, they are especially good for portable players. Oddly while they play extremely well with portables, the K812 themselves are big and clumsy and not very portable themselves.
The AKG K812 are great headphones, but I prefer my Stax or Beyer T51i better. To each their own; these AKG excel at clean, clear sound with great unemphasized bass, but are just a little harsher than the other headphones I prefer.
When you buy the best today, you'll be enjoying it for decades to come. Unlike wasting even more money on an HDTV/4k/UDTV or whatever electronics that you'll be sending to the dump in a few years when the next great thing comes out, these headphones may very well outlast you. They aren't junk from China and they won't go obsolete. These are completely passive transducers; they are electric but there is nothing electronic about them. They are about as electronic as an extension cord; these are passive devices like any other fine European handmade musical instrument.
A great advantage of the K812's low impedance is that they work and sound great with no need for any external amplifiers. I can't vouch for any off-brand MP3 players like LG, HTC or Samsung, but I do know that if you're using an Apple iPod, iPad or iPhone, they all have great low-source-impedance headphone amplifiers and sound fantastic with the K812.
Since you won't need to buy an amplifier to enjoy these, the K812 just became much less expensive.
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13 November 2014