McGary Audio

Thursday, September 24, 2015

Hi-Fi/Pro Headphone Review!
AKG K812 Dynamic Open Back HP
Scores Points In the Living Room or The Studio



Brevis...
Price: $1,995
Likes: Accurate bass, impressive imaging
Dislikes: I would be nitpicking....
Wow Factor: one of best open-back HPs
More info: AKG-K812

 by John Gatski
  I have always appreciated AKG’s dedication to building the better headphone. Sampling numerous models over the last 25 years from the popular studio K240 to my reference K702 Anniversary, AKG strives for that accurate, detailed on-ear tone that golden ear professionals and audiophiles are always searching for. In fact, the AKG K702 is one of my reference headphones I use for testing.
  I had high expectations for the company’s new, made-in-Europe studio flagship open ‘phone: the $1,499 (street price) AKG K812, and it did not disappoint. In fact, the headphone is exceedingly impressive in its ability to deliver wide, deep instrumental layering, making it one of the most detailed headphones I have ever heard. The fact that it is marketed as a “pro” headphone should not diminish its potential for audiophile use as well.
  With its tight bass, pin-point transient response, the AKG K812 is the perfect headphone for professionals in their work with ultra-detailed, hi-res music. And I am betting that picky audiophile headphone listeners will seek them out as well. Good, accurate sound transcends the pro and the audiophile/hi-fi world.

  I did extensive listening sessions in my home recording studio rig with the K812, but they were so good that I also plugged them into numerous audiophile HP amps, such as the Benchmark DAC2 DX and Mytek Digital Manhattan, as well as my Bryston BHA-1 discrete headphone amp. I also played the K812 with several hi-res portables, such as the superb (and now discontinued) IBasso DX-90 and Astell-Kern AK-100 Mark II. Results were equally as impressive.
  Although billed as a ”professional” headphone, the AKG K812 can easily be purchased from professional/consumer Internet order sites, such as Amazon, B and H, Musician’s Friend, Sweetwater and many others.

Features
  The AKG K812 drivers feature 1.5-inch Tesla magnet structure with dual-layer voice coil. The 53-mm transducers (the largest ever for an AKG headphone) are housed in an open-back, circumaural design. The K812 was designed for low listener ear fatigue and on-ear comfort during long mixing or listening sessions: An open mesh headband and 3D-shaped, slow-retention ear pads enhance comfort. Unlike the K702’s soft foam pad, the K812 foam is housed in a synthetic covering. I found the K812 comfortable, though not quite as cushy on my ears as the K702, a reference headphones that I use on a daily basis.
AKG K812 Pro Audio Editing Compputer
AKG K812: premium pro monitor and hi-fi HP

  You can adjust the headphone to your head by pushing a button on each side to move the ear cups, which expands the circumference of the overall fit. I got them to be snug, but not too tight over my glasses ear pieces. As an open phone, you can hear everything around you.
  Spec wise, the K812 numbers are impressive: The dynamic magnetic driver headphone is spec’d at 110 dB SPL/V sensitivity, 5 Hz - 54 kHz frequency response (no tolerance listed; real-world frequency response likely 40 Hz to 25 kHz), 36 Ohms impedance and 300-mW maximum power handling. The K812 comes with a 9.85 ft, oxygen-free cable (pro LEMO termination on HP end) with 3.5 mm (1/8-inch) connector. The package also include a 1/4-inch converter. The headphone weighs in at 13.8 ounces. For your $1,500 bucks you also get a nice wooden mount stand for the headphone. All in all, a nice package for a premium headphone that is more expensive than many Asian-manufactured premium headphones, but not out of line for a European or high-end American HP.

The audition
  Since the professional division of HARMAN bills this as a mixing/editing/mastering quality headphone, I put the AKG K812 into the recording studio. I played a number of freshly recorded 24 bit/192 acoustic guitar tracks from the Mac workstation into a Benchmark DAC2-DX DAC/HP amp. The first sonic attribute that I noticed was the spacious soundstage. The K812 has the ability to not only reveal the air between the instruments, but does it in a more up-close fashion — making it easier to hear the subtle musical nuances. The bite of a pick across phosphor bronze guitar strings, for example, emerges a bit bigger with the K812 vs. the K702.
  On several piano recordings of a Yamaha U1 upright recorded in stereo, the K812’s up-close focus relayed more sonic information; that key plink attack decay sounds utterly lifelike. The K702 delivered the attack in a slightly more gentle fashion and the sound did not seem as “close” as the ‘812.
  On Jazz recordings, I found the K812’s uncanny ability to resolve the instrument track layers to be a useful tool in listening to mix placement. You can better hear what you are doing as far as panning, level settings and other mix functions to get the right balance of each track. The K702 still does the job, but I just hear a little more into the mix with the ‘812. And it is not a phasey, false stereo impression. It is just wider and deeper.
AKG K812 and portable hi-res photo
K812 matches up well with hi-res portables

  The K812 really excels in the bass department — in that it is very flat for a headphone — and without mid-bass emphasis that I hear in numerous other headphones. Unlike bass-heavy studio headphones, such as the Sony MDR-7520, the K812 bottom end is clean, tight and fast with the energy of a really good speaker. It is part of the reason you can hear so clearly into the midrange and treble. No diverting bass boominess to mask the subtle, upper-frequency sounds.
  On drum cymbals, I did notice the 812 renders them with a touch more metallic sheen than the ‘702, but I would not call it exaggerated. Those engineers and musicians end users who know what real music sounds like will appreciate the balance of the AKG K812’s audio delivery. Comfort-wise, the 812 is very light on the ear. In mix and mastering sessions I could wear them for hours without them hurting my ears, though the direct foam-to-ear of the K702 seemed a tad softer.

A double-duty headphone
  Overall, as a pro studio headphone, the K812 has to be one of the top HP’s I have heard for mixing and mastering. The level of detail, space and dynamic delivery is top-tier, but how does that translate into the hi-fi world? Well, it should be the same. A quality, accurate pro headphone should be just as useful for an audiophile. And that, indeed, is the case with the class-leading AKG K812.
  Via my audiophile HP amps and DAC/HP amps, the K812’s well-projected stereo image and dynamic, clean bass were perfect for hi-res music. When I plugged the K812‘s into the Oppo HA-1 DAC/preamp/HP amp to do some LP listening (Clearaudio turntable, Benz cartridge), the records never sounded better. My Wes Montgomery — Full House, the half-speed mastered edition LP, showcased the tight, jazz guitar ensemble, with its dynamic finesse perfectly in place through AKG K812; the cut’s lean, yet muscular bass drum sounded about as good as I have ever heard it with a headphone.
  On Classical music, the K812’s dynamic precision and deep soundstage flattered every kind of instrument I put through them. My Heifetz Living Stereo violin-performance SACDs sounded gorgeous through the K812, driving them with the Bryston BHA-1 discrete headphone amp.

  Switching to a hi-res portable, the IBasso DX-90, the AKG again revealed that welcome accuracy tone. Although the AKG is low impedance, the IBasso drove the ‘phones to high volume levels without clipping. On the 24/96 hi-res version of Jason Mraz’s hit, “I Won’t Give Up,” the AKG HP reproduced the opening bass line, with acoustic guitar accompaniment, not projecting any boominess. Many headphones with punched-up midbass response sound muddy on this track. The K812 allows the energetic bass line to emerge, but does not smear the intricate acoustic and vocal tracks. Very nice indeed.

New classic HP for Classical
  On Classical music, the K812’s dynamic precision and deep soundstage flattered every kind of instrument I put through them. My Heifetz Living Stereo violin performance SACDs sounded gorgeous through the K812, driving them with the Bryston BHA-1 discrete headphone amp. All those analog-recorded, Stradivarius string/bow harmonics emerged from the HP without additions or deletions in the tone.
  With such accuracy, no genre of music sounded bad via the K812. My early 1980s Placido Domingo CDs relayed all the power of the tenor’s range without sounding hard or sibilant. With the same precision, the AKG also relayed the SACD edition of Gene Bertoncini - Body and Soul nylon string guitar album. The finger-picking nuances flourish on this album and the AKG reproduces each track with speaker-like textures. The track “Greensleeves” sounded so good, I listened to it five times in a row through the K812!
Headband and frame are lightweight and comfy

  As I previously mentioned, the only negative I found with the K812 was an initial, slight metallic, sonic edge on drum cymbals, stick or brushes, but that character dissipated a bit as the drivers broke in. Of course, these open phones do not isolate well from outside noises, but such is the nature of open designs. The trade off is a more accurate bass.
  The AKG-812’s fit and finish are excellent. There is little mechanical noise when you move your head, and they stay put. Although AKG headphones are not always easy to drive with some amps, all my HP amp sources including an old Panasonic CD player from 1999, could drive it to loud enough levels. And kudos to AKG for keeping the cord straight. I do not like coiled cables that come with many headphones today. They don’t let you move as far from the source as the straight cord.

The verdict
  The European-manufactured, AKG K812 has the widest and deepest soundstage I have ever heard from a mass-produced stereo headphone. With its tight bass, pin-point transient response, it is a perfect headphone for professionals in their work with ultra-detailed, hi-res music. And I am betting that picky audiophile headphone listeners will seek them out as well. Good, accurate sound transcends the pro and the audiophile/hi-fi world. As an added bonus, the K812 is quite comfortable and the low weight makes them easy to wear for long periods of listening. Definitely worthy of our Everything Audio Network Stellar Sound Award.



  John Gatski has been evaluating consumer, audiophile, home cinema and professional audio gear since 1988. In 1995, he created Pro Audio Review, and he has written for Audio, Laserviews, Enjoy The Music, The Audiophile Voice, High Performance Review Radio World and TV Technology. Everything Audio Network is based in Kensington, Md. Articles on this site are the copyright of the ©Everything Audio Network. Any unauthorized use, via print or Internet, without written permission is prohibited. John Gatski can be reached via everything.audio@verizon.net 



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