You can take something like the HE-500 planar to try to match the K550′s technicalities, but even then the AKG K550 would still be better on many aspects. The background is still blacker on the K550, the sound cleaner, and the soundstage imaging, accuracy, depth, and coherence all being superior on the K550. Not to mention that the K550 runs fine straight out of a Fiio E10. The HE-500 is still the more musical sounding of the two, in my opinion, but given the price difference, easy to drive factor, and the K550′s mostly superior technicalities, it’s a hard battle for the Hifiman. AKG really has struck gold with the K550.

One area where the K550 deserves a spotlight is in the driver efficiency rating. 114dB/V makes it the easiest to drive full size headphone that I know. And that’s with a 50mm diameter driver.  What that means is that the K550 is almost as easy to drive as ultraportables like the PX100. Pretty amazing accomplishment from AKG in my opinion.

I think we can all agree that the K550 is one of the most handsome looking headphone in existence today. The headphone has been high on my listening list from the first moment I saw its photos. That matte black and graphite look with high quality plastic, leather earpads, and metal headband looks extremely slick. Holding the headphone in my hand, I can confirm that all the publicity photos are indeed telling the truth. The build quality is first class, and except for the faux leather pads, should be compared to the best headphones in the industry. Sennheiser HD700? Shure SRH1840? I’ll take the K550′s build any day. The fit of the K550 is also a big improvement over the K701. The pads rest very well, and the overall headphone felt a lot more comfortable than the K701 is. Not only excelling in terms of design and build, the K550 is also one of the most comfortable headphones in existence today. Combine that with the excellent sound, and if I was doing a point-based review, the K550 would’ve come out with a near perfect score.

The K550 has received my respect from the first moment I’ve listened to it. Burn in time was very brief, and in a matter of hours the bass cleared up and I was hearing the K550 in its best form. I can tell immediately that it was an improvement from the K701 as I’ve never remembered the K701 sounding so clean and with such a black background. But it was not until I went and did a direct comparison with the K701 that it really occurred to me how far the new AKG is from its predecessor.

While I’ve never been a big fan of the K701, it was mostly due to sound signature and I’ve always acknowledged it as having a very solid technicalities in the $300 price bracket. I may have described the K701 as being ambivalent and lacking musicality, but I never really associated it with words such as fuzzy and grainy. And yet, next to the K550, the K701 becomes just that: fuzzy and grainy. It was more open sounding, but the much improved instrument separation on the K550 made the K701 sounds like a vintage headphone. I think these comparisons with the K701 should give you an idea of how much of a better headphone the K550 is. I can’t even imagine the price tag being $300 as I can imagine the K550 competing with Shure’s new $700 SRH1840.

At the end I just want to congratulate AKG for bringing such a technological leap into their new headphone. The K550 should be on the list of everyone looking for a new $300 headphone. I can’t praise it enough, and indeed this review is definitely the most positive review I’ve written on an AKG.

Styling
After the rash of gaudy and ostentatious "rapper" cans I've reviewed lately, it's refreshing to see a headphone designed for an adult. These are really an elegant and understated headphone...just beautiful! Sporting a variety of sumptuous materials and textures in various and harmonious shades of gray, I find myself thinking these are among the most tastefully designed headphones I've had the pleasure to behold. Superb!

Comfort and Isolation
This is an extremely comfortable headphone, which isolates relatively well, but during measurements I found them finicky about position and clamping force in the extreme. Out of the box, it seems to fit my moderately large head very well, but placing it on my measurement head was another story altogether. People with small heads will need to adjust the headband by pressing it inward and making it curve a bit more to fit tighter and achieve a proper seal. Without doing so will net poor isolation, and a pretty severe change for the worse in sonic character. Once properly adjusted, however, the comfort and sound can be endured for hours with great pleasure.


Sound Quality
Wow. Just great ... for a sealed headphone. Many in the headphone enthusiast world are going to b**** and moan: "But the Denon AH-DX000 sound so much better!" And they already have in this thread, but I don't think they're really getting it: these are sealed headphones! I agree that the Denon AH-D2000 is a slightly better sounding headphone with a more refined and properly articulate treble, but the Denons (D2000, D5000, and D7000) are far from sealed. I love recommending the D2000 to audio professionals because they are articulate and clear, but I always have to warn that they really don't seal very well...hardly at all, in fact. So the fall-back position for a really good sealed headphone seems to be the slightly biting Audio Technica AT-M50 or somewhat woolly Shure SRH840. Lately I've been turning to the Skullcandy Mix Master as a top-end sealed can, but it's not very refined. None of them really turn the trick.

The AKG K550, on the other hand, is a very well balanced sounding headphone, and, to my ears, bests the above mentioned cans in terms of overall performance. They're nice and tight in the bass, where I find the SRH840 woolly, and the Denons a bit loose. The midrange clarity is very good and quite even for a sealed can, presenting the upper mid-range/low treble beautifully and giving voices their full throat. The best of the bunch here.


The K550 will now be my go-to recommendation for audio pros and headphone enthusiasts alike needing both good isolation and solid audio performance. These will find a place on my Wall of Fame due to very good overall performance on all fronts. Highly recommended.