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.
It does benefit from an amp, however, as the K550 is very resolving to the quality of the amplification and the source. But even more, that bass impact I was complaining about, does get better with a good strong amp. I enjoy the K550 with almost anything I use it with. From the Fiio E10/E17, the CLAS/ALO Rx Mk3-B combo (single ended), the Bottlehead Crack, to the RSA Dark Star. The Dark Star’s high gain level does lead to some hiss in the sound, but otherwise it gives the grandest sound that’s hard to beat with the smaller amps.
Build Quality and Ergonomics
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.
Gear Used for Review
Source: Ipod Classic, Cypher Labs AlgoRhythm Solo, Fiio E10, Fiio E17, KingRex UD384, Altman Tera Player, HRT HeadStreamer, HRT iStreamer. Amplifier: ALO Rx Mk3-B, RSA Dark Star, Bottlehead Crack, JDSLabs C421 Headphones: AKG K550, K701, Sennheiser HD650, HD580, Hifiman HE-500