[REVIEW] AKG K612 - the underpriced underdog
Aug 9, 2014 at 11:30 AM Thread Starter Post #1 of 2


Dec 28, 2010
I myself haven’t been extremely well-versed in writing reviews - but this is an attempt to provide the community with a review on a less well-known headphone, the AKG K612. I settled on this decision since I was looking to experiment more with the open-back sound (most of my cans have been closed-back purely because I need the isolation when doing studio recording)
I have been in this ‘audiophile’ business for 6 years now. Most frequently I rely on the community here on Head-Fi to make my purchase decisions; across the years I have accumulated an array of equipment.
I will be basing this review on the K612 output from 3 sources - straight out from an AK100, using a Audio-Technica AT-HA26D amplifier, and from a Denon micro CD receiver, the RCD-M39.
Headphones that I will be comparing the K612 with:
  • AKG K550
  • Beyerdynamic DT770 32 ohm Anniversary Edition
  • AKG K712
  • Shure SRH940
  • Shure SE425
Sales Package/Build Quality
The AKG K612 comes in a relatively spartan packaging. The box is wrapped in a cardboard sleeve with the usual technical specifications and special features emblazoned across the front and sides. Inside the box you find the headphone, and a 3.5mm to 6.35mm adapter (⅛” to ¼”).
The sales package speaks nothing much - but I would definitely have wished for more accessories to come with the headphone, most notably a pair of spare earpads (AKG earpads are notoriously hard to order here where I live)
The headphones are typical of a auto-headband adjusting design. The body doesn’t show much flex that I’m uncomfortable with. However, I’d say that the build quality is definitely a notch below Beyerdynamic’s. Some users may have issues with the polycarbonate finish that looks cheap. I would knock some points off this if not for the price (I got mine at 179 USD, which is a steal considering what this headphone is capable of). The cable is somewhat thin and not removable. I have my reservations on the durability of the cable even though AKG covers the headphone with a 2 year warranty.
Typical AKG comfort: cushy pads! The velour is surprisingly breathable, superior to the ones you see on the Shure SRH940. Clamp is medium (I have a relatively small head) and the self-adjusting headband is good for long sessions, unlike the K702. However, positioning on the head seems to have a slight effect on the sound and detail retrieval. Do experiment because your mileage may vary.
Initial Impressions
Fresh out of the box, the K612 sounds a bit loose on the high-end. However, bass seems well-controlled and is tight for an initial impression. To some extent it sounds like a tamed down K702 (which I did not purchase due to the extremely hot treble). Afterward, I left the headphone to burn in for a few hours. The headphones seem to not like high volume levels - the drivers distort at higher volumes.
Sound Quality
Bass: AKG headphones aren’t known for bass. Many consider them bass deficient. There is enough bass for trance (that I listen to quite frequently), but certainly this headphone will not satisfy bassheads.
K550: The K550 is noticeably more bass deficient. The K612 has better sub-bass and mid-bass texture.
SRH940: Has the more sonically accurate bass. The bass extension is not as deep as the K612.
DT770 AE: This is a basshead can that sometimes sounds like there is a subwoofer next to your ear. The K612 has the edge here in terms of realism rather than bass impact. If not well controlled the AE can sound quite boomy thought impact and rumble is present.
K712: The bigger brother of the K712 has more detail in the bass registers, though impact level is similar.
SE425: BA earphones don’t bode well for bass. The K612 wins on all accounts here, though the SE425 may have a debatable edge in terms of detail retrieval.
Mids: Vocals have a little airy feeling over here, especially female vocals. This headphone allows vocals to rise to the top of the mix (though not the same degree as Shure IEMs). Guitars and strings are rendered with clarity and precision. Nothing special here, though.
K712: Again, more realistic mids.
DT770 AE: The Beyer has a touch more air to vocals.
SE425: Fluid, liquid mids - the K612 can’t touch them here.
SRH940: Surprisingly the AKG performs quite closely to the 940 here.
Treble: The K612 has enough sparkle for most music. Nonetheless it still cannot be described as a bright headphone. Sibilance isn’t an issue unlike the K550/SRH940, but when present in recordings it will present itself.
DT770 AE: Has more sparkle, but that seems to affect cup resonance and give it a closed feeling.
K712: Has more air and detail about it. Treble is also a lot less congested.
Soundstaging and General Comments
The K612 is a remarkably detailed pair of cans for the money. In some ways they can rival the K701/K702 in terms of detail retrieval and balance. However, the K712 performs better across the board (but is double the $$$).
Amp and DAC pairing are very important for this headphone. With an impedance load of 120 ohms, an AK100 is not very adequate to power it. In fact, it is more suited for desktop applications. Being a very neutral phone, it seems to acquire different characters when paired with different equipment. The slight warm signature may be an acquired taste: some people have recommended using tube amps though I have not tried it yet.
Imaging is accurate and wide, though this seems to be quite dependent on the position of the earcups around the ears. I have not tried swapping the earpads to see whether it has an effect of the sound though I suspect it may do so.
The K612 represents a great value for money at their price (which in some, if not all ways outperform the K701/2). However, its build quality can cause some concern. If you’re looking for a neutral open-back headphone and are cash strapped, this is your best bet. It can outperform many headphones, both closed and open at higher price levels. Even if this headphone were to be priced 100 USD more, I might still consider it worth the money.
[edit: pictures to come when I have the time!]

Users who are viewing this thread