AKG K550 Closed-Back Reference Class Headphones - Black

I think AKG are onto a winner with these headphones. The sound quality is excellent and the isolation is first class. I use public transport a lot as I don't have a car and for this the K550s are very well suited. I listen to classical music, often quite quiet music and so the isolation is very important.

I have two other pairs of AKG headphones, my much loved AKG K702s and my K271 MkIIs. I use the K271s mostly for monitoring sound when I am recording video. I used to use them on public transport as they are closed back. The K550s are the preferred choice for this now.

The K550s do not sound like my other AKG headphones. They have a forward and full midband and the treble is softer. The treble is not as detailed as my K702s. I think that the K550s will have a wider appeal that the K702s because they will, probably, sound better with pop/rock. However they do sound excellent with classical. I've been listening a lot to Debussy: Preludes (2CD), Claude Debussy, Alexei Lubimov. I bought this at Amazon actually. The piano sounds really beautiful with the K550s, the notes are full and with lots of expression.

Although these are closed back headphones it is remarkable how open sounding they are. They will present orchestral works with a surprisingly large soundstage.

I do use them with a small portable amplifier plugged into my iPod Touch. However they will play absolutely fine plugged straight into the iPod Touch. These are very sensitive headphones. I use my small amp because it produces a better sound quality than the amp in the iPod Touch. I think that for quality purposes it is a good idea to get a good portable amplifier to add to your portable source. The downside is that the more you have the less portable it is :)

I have one criticism of the K550s which is that the cable is not detachable. I would really like to be able to use a shorter cable when I am using the headphones on public transport. The cable with them is far too long for this and it is a nuisance. I do like the longer cable when I am listening at home, so for me the ideal is to have a detachable cable so I can attach a shorter cable or a longer one depending on situation. This is what I do with my K702s and my K271s.

I will add that there is no sonic disadvantage imho to the captive cable. I do not recommend people spending money on the absurd after-market cables for headphones. The advocates of these claim all kinds of benefits but when they demonstrate this in blind listening tests it will be of interest.

The K550s have an entirely new headband design. Unlike my K702s and my K271s this one does not self-adjust for different head sizes. You have to adjust it yourself. Fortunately this is very simple and the advantage with this headband is that it is much neater and closer to the head all round, so you look less like a cyberman. Another advantage with the K550 design is that the headphones will fold flat-ish. This is very useful for putting them in a briefcase (which is what I do), along with your laptop or what-have-you. However these are pretty large headphones so even flat they are quite a big object, but much easier to deal with in their flattened state.

Background: I need to used closed back headphones to avoid sound leakage in both directions and so they are "family" friendly.

I won't repeat what has been said about comfort, suffice it to say that they are big, but comfortable.

The sound is what I will focus on. I'm comparing to the closed back Sennheiser HD215 which is 1/3rd the price, but a favourite of mine. Whilst the Senns will provide competent sound, these AKG units allow the music to have much more space, more like open backed headphones. The result is you can discern more, resolve more layers and hear the start & end of say, a snare drum or brush on a drum more clearly.

Listening to complex jazz like Tomasz Stanko, you can really tell the difference and these are like the difference between a slightly dirty window and a crystal clear one. They project more, but without being fatiguing. Trebles sparkle, but do not irritate. The bass is laid back, maybe more than I would like, but it feels quite natural, without annoying thump.

Switching to say, Angel or Teardrop by Massive Attack shows the ability to hold a decent bassline, without it muddying the mids and treble. The angelic voice of Liz Frazer comes through beautifully on Teardrop, not drowned out by what is an absolutely monsterous bassline.

Next, Jethro Tull - Skating away. This is a complex track, with various instruments coming in and out of the mix. The AKG's managed to resolve the different instruments cleanly from the vocal. You can actually tell that the vocal is slightly compressed in the recording, which shows how well these headphones reveal.. The Indian Tabla sounded rich but not overly aggressive. The percussion and accordian were clearly discernable from the electric guitar chord.

Next, Love & Affection by Joan Armatrading. This shows these 'phones at their best. Her vocals absolutely sparkle and the double tracking of her voice is separable. The strings are lush, with the sax fluttering over with a sense of space. They really sound like high quality open backed units.

Moving onto a popular one in Classics, Vivaldi's Four Seasons - Winter. You cannot easily get orchestral placement with headphones, but this begins to. As classical has a high dynamic range, it needs to be able to resolve highs, lows and sudden sound well. This does that admirably.

For spoken word, you can make out the studio acoustics reasonably well and the sound from decent BBC stations is rich and suitably plummy. Vocals in plays are superb, with an intimate feel.

My only criticism is that they can sound a little bright & splashy at times. I hope a little breaking in will mellow them out. UPDATE Feb 2013: They have mellowed out nicely. I can wear them for extended periods without discomfort.

The sound has a neutral balance, whilst allowing sonic layers to have their own identity, like a puff pastry, it unravels in layers. I'm pleased, even at this price, which is more than I thought I would ever spend on headphones.

I switch back to the Senns just to see if the K550s are really that much better and they are.

I received these, by request, as a gift this Christmas, bought from Amazon as they are probably the most competitive price on these headphones in the UK. Over the moon at getting what I asked for I immediately opened the classy box to try them on. Greeted by a fowl stench of artificial leather, please note there is no way the ear pads are real leather after that smell! The headphones feel heavy in a solid way to pick up, they look stunning and feel well built, and I am convinced they are. The whole design is a work of art.

First impressions plugged directly into my laptop playing apple lossless files, with the EQ disabled (flat). They sounded so good that I almost started to well up at rehearing my old favourites in all their well deserved detail, they really blew me away that much!

After having 3 days of use out of them I felt I was ready to give my full opinion. I guess they have had less than 10 hours use so far, so are not fully 'broken in' or 'burnt in', regardless of whether you believe in that. However my ears have had time to adjust and get used to them, and I have noticed their traits, and what they are good at / what they are not so good at. So, onto how they sound...

Bass:
The sound is INCREDIBLY balanced, as in there is very little volume difference between different frequencies, with one slight exception in the high end. Starting at the bottom, the bass is the most well controlled bass I have ever heard! On a frequency sweep from 100Hz - 20Hz there is very little volume change at all, apart from the natural roll off towards the sub bass frequencies. However these headphones do reproduce with ease frequencies right down to 10Hz. This gives an amazingly tight bass that is never out of control and never boomy. However this has a downside, and that is no frequencies in the low end jump out at you, so the bass is smoother and flatter, but much less engaging. There is no large spike around 60Hz that so many speakers tend to suffer from, instead it is completely smooth, so if you are an absolute bass freak then I suggest you go and buy some Monster Beats as they have tons of uncontrolled and unrefined boomy bass. This means there is next to no EQ'ing required for the K550's to achieve a balanced sound. But this does give the effect of a 'calmer' and dare I say it 'quieter' low end. But a studio engineers dream for mixing bass instruments with! By giving all the low frequencies room to be heard bass instruments sound much more detailed then you could ever imagine, as they are not being masked by dominance in one particular area.

Mid range:
The mis are very smooth throughout with little difference in level from 200Hz - 3.5KHz. It is incredibly detailed and has a brilliant wide sound stage, allowing instruments room to 'breath' within the song. It really allows vocals to shine through, and lead guitar work sounds more detailed and fluid than ever.

Treble:
The downside of the K550's is the presence boost at around 6-9KHz. It is noticeable, and at high volumes can come across as a tad 'harsh' and 'grating' on the ears. However at low-normal listening levels it is much less accentuated and adds to the tremendous level of detail in the sound. From 10KHz onwards the treble is much flatter and smoother, and maintains incredible levels of detail without sound harsh to the ears. Due to this peak in the high mids and low treble ranges it generates the effect of there being a slight lack of low mids. I also particularly favour a healthy amount of low mids in my sound, so it is something I would want to boost slightly on an EQ. Although it is not a necessity for most music.

Summary:
Listening to "Sultans of Swing" by Dire Straits the guitar instantly sounds very smooth but also very detailed throughout the song. The slight boost of high mids favours this style of guitar sound, mainly clean, with a hint of break up. The hi-hat and ride cymbal sound crisp and detailed with the slightest bit of decay being audible ringing on throughout the song. The bass guitar and kick drum are also present from the beginning of the track and are perfectly in balance with both them selves, and the rest of the instruments. The kick is really really deep and tight, with little dominance of the high bass. This is where the bass guitar shines, it is very flat in response, so ever note is equally loud, the way it should be heard, with no quiet or boomy spots. This style of music sounds absolutely brilliant on these headphones, and only increase with detail as you turn it up. I also find acoustic guitar sounds really very impressive on the K550's.

Contemporary metal doesn't fare quiet so well. Killswitch Engage's - "My Curse" holds the same high level of detail and wide spatial stereo image, however the detuned heavily distorted guitar thrives of tons of low mids. I felt the K550's let too much of the high mid range to shine through losing some of the 'dark' and 'thick' quality this style of metal is meant to sound like. The bass was still as tight as ever throughout the song, however on the hole could be more dominant.

"Dreaming of You" by indie rock band The Coral starts with a 'raw' uncompressed sounding bass guitar. However despite this it is very smooth and flat throughout the track. No matter what you through at these headphones the bass they deliver is tight and smooth and true down to the last detail. The headphones accentuate the stereo imaging and panning from the main guitar, and other instruments such as sax and keys are much more noticeable than I ever remembered. The drum kit is mixed very quiet and that is where it stays. These headphones produce the sound as the studio engineer intended you to hear it, not how Dr. Dre wants you to hear everything.

Listen to "When We Stand Together" off Nickelbacks latest album at 75% volume, the song starts with a heavily processed but absolutely THUNDERING rumbling bass, you can hear every last rumble the strings would be producing whilst it still being very tight and powerful. This is followed by an nice contrast of an acoustic guitar which is given tremendous detail due to the presence push these headphones seem to have. This leaves a nice hole in the mid range to be filled out by a perfectly smooth vocals. This was the first song I listened to when I tried on these headphones and it still blows me away how good it makes it sound.

Comfort / fit:
These headphones are huge, and I have a very small head. I wear them on the shortest setting, number 1, but they still fit me fine. People say the struggle to get a good seal from the cups which can result in reduced bass response, but they seal perfectly for me and the pads are lovely and soft! In fact, if I push gently on the outside of the cups I can feel the pressure being exerted on my ear drum, not leaking out.

The headband has a very thin layer of padding, I would have thought they could have made it slightly thicker, but saying that it is not uncomfortable at all. In fact I find these headphones incredibly comfy to wear, and after 30 minutes of sitting listening I actually forget they are on my head until I go to move! That is how nicely they sit. Plus the huge cups keep your ears nice and warm!

Practicality:
Well the 3m long cable isn't ideal, I would have much preferred a detachable one but you can't have everything. I braided my cable to shorten its length and it did the job fine. They fold flat to put in a case, however there is particular case designed for them so you will have to find a generic one which fits which isn't ideal either. Despite them being large cans they grip my small head firmly and I can't see them being any issue wearing them out and about, and being closed back they leak very little sound even at high volumes.

I enclose a link to some frequency response graphs and sound test graphs of these headphones if you care to know more about the technical stuff: [...]

Overall I am very pleased with these headphones for the price, and I'm sure I will grow to like them more and more, and they will break in more with time and smooth out a bit more of the presence boost. I highly recommend these headphones to anyone wanting a very balanced and detailed sound, wanting to hear the music how it is meant to be heard, not how you want to hear it (an EQ does that bit!).