Author Topic: REVIEW: AKG K812 Reference Headphones  (Read 1182 times)

Offline capetownwatches

REVIEW: AKG K812 Reference Headphones
« on: January 01, 2018, 09:11:42 PM »

Headphone type: open-back
Max. Input Power: 300 mW
Audio frequency bandwidth: 5 - 54000 Hz
Sensitivity headphones: 110 dB SPL/V
Rated Impedance: 36 Ohms
Detachable 3m cable with locking 3-pin LEMO connector

AKG launched their flagship open headphone as successor to the K712 in 2013 to much concern on the various fora over high cost and a "tizzy" top end (as described by Innerfidelity's Tyll Hertsens).
There was speculation, based on a few early reviews, that the much-anticipated K812 was not going to live up to AKG's promise of delivering "the world's finest dynamic headphone."

Now that it has been around for a while, the dust has settled and sanity has prevailed - additionally I have had the opportunity to live with it for a while, and use it with a variety of front-ends, and I can put it out there as absolute, no correspondence will be entered into, crystal clear and unambiguous fact that the K812 is indeed the finest dynamic transducer I have had the pleasure of experiencing thus far in my pretty much lifelong hi-fi journey.

"For $1499, you could do a lot worse than the AKG K812.  Pretty much just buy any other $1499 headphone and WHAM! you’ve done worse.  Because these headphones will make you hear God."

The packaging befits the retail price, and the Sieveking Omega wood stand is a nice touch, although I'd prefer no stand and a lower price.
Build quality is quite superb with lots of metal used in place of plastic and smoothly operating gimbals that suspend the cups.
The headband is a wide, perforated leather of good quality. Adjustment via a toothed slider is finicky and well-nigh impossible to do on the head, but once successfully sized these will not move a micron.
Ear cups are cavernous affairs to accommodate the 53mm 1.5 Tesla drivers, set at an angle and a long way away from the user's ears.
The ear pads are a uniquely shaped protein leather with what AKG call "sound sealing" cutaways designed to create a better seal. It works well.

Once on the head these are exceptionally comfortable and much lighter at 370g than they look.
They are substantial headphones, the irony being that they are quite possibly the best portable headphones on the planet but they really cannot be worn outside the home or studio, unless you want to be stared at as if  you had an additional appendage

OK, formalities aside. All listening was done using my Windows 7 Pro Media PC running JRiver MC23 with files ranging from 16/44.1 FLAC to DSD128 and everything in between.
Amps used were Audio-gd NFB-11 DAC/Amp via USB, and the brilliant Woo Audio WA7 Fireflies valve driven Class A headphone amplifier to see how it would fare when fed some tubey goodness.
I did not use the Woo's own DAC, preferring rather to go with feeding it from the NFB-11 via RCA in order to keep the source consistent.

These are headphones that demand superlatives when describing a sonic signature that is at once huge and holographic with a pinpoint accuracy of instrument and air, and yet intimate and detailed enough to convey the touch of finger to piano key or the whisper to a band mate.

This is the first thing that one notices, the sheer size of the musical landscape presented to one's grateful ears.
The HD800 may throw a wider stage, but the K812 does it more organically - it sounds truer to the original recording in my opinion.
This makes it a thoroughly exciting and resolving listen - well-known recordings reveal nuances previously unnoticed, live music really does feel "live".
Driven by the NFB-11 on low gain, Michael Shrieve's bass drum on Santana's "Choo Choo" from 2016's IV smacks me upside the head like a 2 x 4.
Finally, an AKG Reference headphone that does bass!
And how does it do bass!

Pick a superlative - full, deep, precise, punchy - they all fit. The K812 goes deep. The incredible "Giorgio by Moroder" off Daft Punk's Random Access Memories  is a great track for testing bass response, and the deep electro-bass and [human] drums have never sounded better to me. Bass slam is easily equal to that of the LCD-2 in both quality and quantity, and it makes the DT990 Pro sound anaemic by comparison.

Equally adept with Power Metal, Jazz, Classical or Pop (only for purposes of this review, I assure you, dear reader), I could listen to this headphone all day - wait, I have...often...!

So it does bass properly. Let me thus cut to the chase - this is a supremely accurate headphone - it does ALL the frequencies properly, and a very wide range of them.
5-54,000Hz to be exact, with a sensitivity of 110db SPL/V according to AKG but independently tested (by Solderdude) thus: 1V will produce 105dB whilst 1mW will generate 94dB.

This makes it a very easy can to drive with basically anything, which is a bit of a rarity when it comes to flagships.
It is why I reckon it's the world's finest portable headphone. It sounds quite ludicrously good out of my LG V20.

But this raises an interesting contradiction. These are marketed as headphones for studio professionals, and they are indeed outstanding reference monitors.
But why a 36 ohm impedance? Studio cans need higher impedance since they are often plugged into gear that has a high output impedance.
I would like to substantiate this, but I don't know how well the K812 might fare when used with an amp that has a higher than 4.5 ohm output Z (using the multiple of 8 rule).

This is also not a turn on for the headphone audiophile who (generally) prefers a slightly higher impedance can, the current crop of low impedance (low sensitivity) Planars notwithstanding.

Be that as it may, using the WA7 in Low Z mode was a revelation in terms of midrange resolution.
The tubes imparted a slight warmth yes, and the K812 responded by dishing up vocals of the highest calibre from Diana Krall and Alexis Cole through Amy Lee, Floor Jansen and Simone Simons.
Mids were organic and natural, without any hint of harshness - even Norah Jones, who I can find a tad screechy sometimes with the wrong cans could not put a foot wrong.
So mids are precisely as they should be with the K812, and again, one is able to put in long sessions without any fatigue.

And so on to that troublesome treble. After Tyll described it as "brutally harsh" the interwebs lit up with speculation.
His measurements pointed to "an area of elevated distortion between 1kHz and 3kHz." This resulted in a "confusing" low to mid treble.

I have listened to many, many recordings I know well in an effort to hear what the heck he is on about, and all I have heard is an extended, highly controlled and resolved top end.

Guitars are rendered with the required crunch and attack, cymbals zing and decay precisely, highs are exciting and engaging. Properly detailed with neither grain nor glare,  I would describe it best as "natural".
The K812 is a magnificent all-rounder, a Goldilocks headphone, to borrow the phrase (which I will since it's a good one).
It simply does everything brilliantly well, with no glaring faults (sorry Tyll, don't know what you're smoking).
Equally adept with all types of music, and from any source, I found myself wanting to listen to music with it at every opportunity.
It is an exciting listen which will reveal absolutely everything in the recording, both good and bad.

AKG have shown that a headphone can be both accurate AND engaging, and that is what makes the K812 very special.
At the price it should be damn near perfect and, for me anyway,  it is.

[Big thanks to Craig for the loaner]  :mates:

« Last Edit: January 01, 2018, 09:20:44 PM by capetownwatches »

Kingrex HQ1=Audio-gd NFB11.32=Little Dot Mkll=SRM252S=Benchmark DAC1 USB=RL Concero

Offline LouisF

Re: REVIEW: AKG K812 Reference Headphones
« Reply #1 on: January 01, 2018, 09:50:15 PM »
Nice Arie, I found your review very detailed and informative - pretty much as you describe the cans! These phones are something to aspire to one day.
"No matter how educated, talented, rich or cool you believe you are,
how you treat people ultimately tells all."
David Avocado Wolfe

I have learned more from people who have differed from me than from those who have agreed with me.

Offline itscraig

Re: REVIEW: AKG K812 Reference Headphones
« Reply #2 on: January 01, 2018, 09:51:04 PM »
as always a very nicely written, and insightful review
thank you for taking the time

Offline Chingy

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Re: REVIEW: AKG K812 Reference Headphones
« Reply #3 on: January 19, 2018, 10:43:34 AM »
Great review Arie, as always, must say, they sound better each hour I spend with them  :mates:

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Offline [HpX]Nemesis

Re: REVIEW: AKG K812 Reference Headphones
« Reply #4 on: March 14, 2018, 10:27:49 AM »
Awesome review!

Sent from my SM-G955F using Tapatalk

Offline capetownwatches

Re: REVIEW: AKG K812 Reference Headphones
« Reply #5 on: March 14, 2018, 04:01:46 PM »
Awesome review!

Sent from my SM-G955F using Tapatalk

Thanks! I enjoyed writing it.

Kingrex HQ1=Audio-gd NFB11.32=Little Dot Mkll=SRM252S=Benchmark DAC1 USB=RL Concero

Offline udwadia

Re: REVIEW: AKG K812 Reference Headphones
« Reply #6 on: April 27, 2018, 12:11:18 AM »
' And so on to that troublesome treble. After Tyll described it as "brutally harsh"  '
i am listening to the K812 driven byAudio- gd R2R ii and concur with your finding ..

Offline udwadia

Re: REVIEW: AKG K812 Reference Headphones
« Reply #7 on: April 27, 2018, 11:30:49 AM »
apologies  . forgot to add that i concur with you that the AKG k812 is not harsh.