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Head-Fi.org › Head Gear › Headphones › Over-Ear › AKG K 550

AKG K 550


Pros: Open Stage, No Congestion at High Volumes, Quality Built, Reference Response Curve, Comfort

Cons: Artificial Treble (can be improved with burn in & DAC/amplifier), Earcups Maybe Too Large For Some


I got these headphones around the national holiday. These came out about 2 years after I had got my K701. I was first attracted by its classy design and colour. I thought I would never get another pair of AKG headphones since K701 has been my favorite all the time. I finally decided to purchase a pair due to the discounted price of $180 USD including shipping in my country; and most importantly, I needed a closed can(s) to enjoy music at night without disturbing others. In this review, I will skip all the con(s) about these headphones and straightly elaborate on the sound quality and cozy build structure of these headphones. The reason is that at this price point, there are really no con(s).


Design & Build Quality

The build quality and design is simple but sturdy, is black/grey but classy, is far from top notch but flawless. I believe the design is better than my K701 because K550 has more grainy metals to withstand any abuse. The headphones are consisting of 3 major parts – the ear-cups, the joint, and the headband padded with synthetic leather. The ear-cups are able to rotate from the joint (by a little), and the joint can also rotate from the headband for approximately 90 degrees. This clean and versatile design allows me to store the headphones in my hobo handbags. Nothing feels flimsy or sticking out which will cause a problem. The headband adjustment is locked by a click. The numbering system on the headband will allow you to adjust the headband length to your most desirable positions. This helps a lot because getting a good seal on this K550 may be tricky because of its size.


The leather on the ear-cups and the headband are so comfortable that I actually enjoy wearing them once in a while. Although I would prefer the alcantara material (like on the K701) for the hot summer, the seal and comfort is better with the leather or leather-like material.


To begin, I was feeling a little disappointed coming from K701 when I was listening to these cans for first few hours. After 60-100 hours of burning in, the bass opened up and the artificial treble (which seemed like plastic spark) smoothed out. As several master reviewers had mentioned, there seemed to be a very slight disjointness between the bass and sub-bass area (of course, they have heard headphones around $1K mark). However, in term of the fullness and tightness of the bass is on par with my K701. Master reviewers would obviously magnified the disadvantages of these headphones, but they should consider there are very few competitions at this price point with this kind of sound quality in a closed full-size headphones. The T5p is triple the price, the build quality on the SRH840 or 940 may not be as good, the M50X may have a smaller soundstage. Nothing is perfect in this world especially with closed headphones. It is easy to make an open headphone sounds good, but it is harder to tune closed headphones. The K550 produced a full and tight bass with good and not-too-forward mid(s), and a nice sparkle treble without any harshness. The vocals are accurate and shine on these headphones.



The overall sound quality is impressive on these closed headphones considering they were at $180 USD when I purchased them. For people who prefer a reference sound signature with price-to-value ratio in mind and an amazing soundstage in closed nicely built comfortable headphones, you will not be mistaken by this K550. Just remember to give it a little time to burn-in and find a good warm source (like my Audioquest Dragonfly) to match the lean signature of this headphone.


Pros: Looks, Build Quality, Decent tonality and fairly flat FR from midrange down to bass, no treble emphasis, decent soundstage for a closed headphone

Cons: Serious peak and resonance in one spot in the upper mids ruins an otherwise decent headphone


First Impression


When I first listened to these headphones, my initial two thoughts in this order were:

1. Wow these sound pretty fast and also fairly even

- 15 seconds later -

2. Wow something is wrong with the upper mids



who cares


Build Quality/Aesthetics

These headphones feel very well built.  I can't speak to their longevity or durability, but they are nice to hold, feel sturdy, the movements are tensioned well and feel solid, there's no creaking of cheap plastic.  The finish feels durable and well made.  One of the better headphones out there IMO for it's apparent build quality and finish. 


They look very nice when sitting on your desk, and in pictures.  A good design, but they are one of those headphones whose looks don't entirely translate to looking good when worn.  They have all the right shapes and dimensions relative to each of the parts, but the whole thing is just too big to look very good.  For their size, I'd say they don't look too bad as they are slim, so they don't stick out horizontally very much and give you the alien mind probe look that grados and many closed headphones do.  The headband is slim too since it comes together at the top of the cups, so it doesn't have that gigantic and unnatractive arc that the older AKG's have like the K240.  The headband hugs the sides of your head well.  Still, the cups are huge even on my big noggin.



Very good except that the earpads just aren't thick/deep enough.  Huge design flaw IMO because everything else was done very well for an extremely comfortable headphone.  The cups swivel in a really nice way since they have a good amount of friction in the movement, so you can place them at the right angle for your head, and they stay there.  Headband is comfy and is the right shape.  But the earpads aren't thick enough to keep the grill over the drivers from hitting your ears.  With such huge, soft earpads this is a pretty big fail IMO.  I tried putting the foam donut shaped inserts that Hifiman has in their earpads into the K550 earpads, increasing the thickness, and it had no effect on the sound and made them supremely comfortable by simply increasing pad thickness.  So as long as you don't have huge ears they should be fine.  Or if you don't mind a little pressure from the grills.  it doesn't hurt too bad on my big ears, but it just would have been so easy to avoid this situation.  I get the feeling they didn't do much real world testing on these and got carried away with computer modeling. 





They overall have a flat, balanced sound from bass to midrange with good tonality, and with a treble presence that is in balance with that part of the spectrum, which is very rare for headphones.  But there is a serious problem spot in the upper mids that ruins this headphone.  A resonant peak in a small part of the upper mids.  I would describe their overall sound as a slight rainbow shape FR, though leaning upwards towards the upper mids for enhanced sense of clarity.  They also can sound kind of fast for a closed dynamic.  Not ortho or stat fast by any means, and not Grado fast, but maybe 6/10 for speed.  Not bad. 



Good not great.  It extends down plenty low, it seems flat, there's no apparent midbass hump, bass does not bleed into the midrange or vocals in the slightest but is also well integrated with the midrange.  There's no "bass + mids"  or subwoofer effect where the midrange and bass feel separated by gaps in the spectrum.  They have a cohesive transition from bass to mids, likely from a fairly flat FR.  But bass is a bit low in quantity despite what the FR measurements suggest.  The bass is in the background on these phones, with emphasis on the midrange.  Not for bassheads at all.  Bass is not bad quality, but it sounds kind of dry and a bit soft, whereas better headphones have more definition and dynamics and detail in the bass.  Not bothersome, especially since it's in the background.  I'd describe the bass as being just enough to provide a foundation and not sound too lite, but too low to sound totally neutral- it keeps your attention on the midrange.  It gets out of the way so to speak, for better or worse.



I'd say the treble on these is very similar to the bass.  Good not great.  There's no emphasis in the cymbal range as far as I can tell.  If anything it sounds a bit recessed in the upper treble.  Nothing sticks out at you here or is glaringly bad.  But the treble is not that clean or precise sounding.  It is a bit rough/textured or papery sounding.  Like the bass, I'd say it's a backdrop for the mids.  Not a treblehead headphone either.  Yet despite this lack of apparent brightness, these phones have a strong sense of clarity about them.  I think this is what people like in this phone.  They don't sound dull or rolled off or warm at all.  Likely because of the slight lowering of bass volume, along with the emphasis in the upper midrange, the "clarity" range in the FR.



Here's the problem.  Both the bass and treble on these are both presented as a backdrop for the midrange but there's a serious problem in this area, so these phones wind up failling short for bassheads, and treble heads, and then have issues in the midrange.  First the good part.


The heart of the midrange and the lower midrange is done pretty well.  Vocals have both the proper richness for a male voice like Tom Waits or Chis Isaak, which is surprisingly rare- they don't make vocals sound thin despite the lack of bass emphasis.  They also don't sound overly rich at all.  Chris Isaak's voice sounds very good.  Vocals also give the proper air and breadth to female vocals like Emmylou Harris or the Audiophile favorite Allision Krauss.  But sometimes vocals reach up into the problem spot and sound off. 


Upper Midrange Issues
There is a spot in the upper midrange that has a pretty bothersome resonant peak.  I kept wanting to call it "glare".  The upper midrange glare isn't the most peircing or painful I've heard in a headphone but it is very bothersome and might be described as severely "jarring".  It doesn't seem to cause me to reach for the volume knob as feverishly as some phones have, but it does keep me from turning them up and leaves me in a state of fear wondering when something is going to hit this problematic range and if it is going to hurt, since it seems to be right on the threshold.  Any instrument in that range sticks out way too loud, and looses proper tonality as the sound in that range gets mangled by resonance and takes on a plastic tonality. You can clearly hear the coloration being added to what should be the original signal.  This is partly because it's such a specific problem spot.  You can sometimes hear an instrument or voice go up in the range and suddenly jab at you by suddenly increasing in volume while taking on this plasticky resonant glare.  The decency of the lower part of the spectrum gives it a "surprise attack" quality which is what generates the fear and hesitancy when listening.  If there was an instrument that existed only in this range, I am doubtful you would be able to hear what instrument it was.  Some recordings play well with this problem spot and it's not grossly apparent because of the frequencies being excited by that recording and the particular balance of the recording (if the recording has a peak in that spot too, it's clearly going to be worse).  But even on these recordings, this spot gives the whole spectrum a cheap plastic headphone feel kind of layed over the sound, as if you are listening to some very good throw away headphones.  I kept thinking of them as the best airline headphones ever.  Much better extension, tonality, more flat, but still plastick-y. 



Overall good size for a closed headpone, has a spaciousness about it, but there's something strange about it as well.  It's almost like there are 2 soundstages happening at once, the lower part of the spectrum sounds more spacious to me than the upper mids/treble, which sounds more constricted.  This gives them a lack of coherency, or a kind of bad crossover effect, where the sound is a bit disjointed.  I think this is because the resonance artifact in the upper mids destroys soundstage by getting in the way of the "trick" the headphones are playing on your perception.  Soundstage is also destroyed by a "driver dildo" that was installed on the back of the driver creating a tiny chamber behind the driver rather than the comparatively larger size of the earcup.  I'm guessing it was placed there in an ill conceived attempt to control the bass, but I have modded a pair of these by removing this dongle, and correctly damping the cups, and the soundstage becomes more coherent. 



Good looking, sturdy closed headphone that is fairly comfortable and has a mostly well balanced, even sound except for a very problematic part of the upper mids that sticks out sorely and ruins them. However, this part may not bother everyone.  If it doesn't bother you ie if you're not sensitive to resonance or FR irregularities, and you are looking for a well balanced headphone erring on the side of being a bit basslite for the sake of clarity, and you want good soundstage these may be a good choice for you.  If you are not bothered by Grados you may not be bothered by this resonant peak.  however, Grados have much more natural tonality, for example vocals sound more life like.  I recently had an MS1 here and despite their colored signature they sound better than the K550 in every way except may soundstage width.  There's no plastic tonality in the MS1's signature. 


Here is a picture of the inside of the K550's cups.  The lack of damping here contributes to the resonant peak, but after spending time with my modded pair which has damped cups, I have found that it is also being caused by the driver itself.  Damping the cups helps, but doesn't fix the problem.  The small rubber thing in the middle of the light gray circle around the driver, is the "driver condom".  This seals around the driver and makes a small enclosure size behind it.  The light gray area are vents, though they seem to be closed off with solid plastic.


AKG K550 inside the earcups- stock. The small rubber thing in the middle of the light gray area around the driver, is the "driver dildo". The light gray area are vents, though they seem to be closed off with solid plastic.


Pros: Linear, smooth bass with great extension. Manages to sound fairly neutral while still maintaining good musicality.

Cons: Multiple issues in treble region. Mids are thin and lack body or presence.

Comparison Review: ATH-A9X, ATH-A900X, AKG K550

Edition 2


I have decided to update this review, not only because I've spent some more time with both the K550 and the A900X, but because I found frequency response measurements for both of them on Golden Ears. I know not everyone likes the way they measure, but since there are no professional reviews of A900X other than on DigitalVersus, and since you shouldn't compare measurements taken by different websites/reviewers, I felt this was the best course of action to take.  I have also updated/adjusted several observations in the sound quality section, a lot of which I feel is much more quantifiable now that I have reliable graphs from the same source to look at.


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1. My Audio Preferences:


  • I listen to mostly new age and orchestral pieces, so natural/realistic instrument presentation and strong vocal performance is important to me (good timbre).
  • I like rich and lively sound presentation. So warm, pronounced mid-range; clear, sparkly, but unoffensive treble; and tight, controlled bass (that isn't overly loud).
  • I dislike over-abundance of bass. My ears are very sensitive to bass; headphones with bass-emphasis make my ears uncomfortable very quickly and gives me a headache after a while (to put things into perspective, the Superlux HD668b is considered bass-heavy by me).
  • I've been a long-time Audio-Technica owner, because their traditional sound signature is very much in-line with what I like: Rich, full-bodied, warm and engaging, with an emphasis on mids. The treble and bass presentation are typically pleasant and unoffensive on the AT's that I've tried. Aside from its narrow soundstage, my old ATH-A9X has always been my absolute favorite for music listening.


~ ~ ~ ~ ~


2. Reason for Choices & Purchases:


While I love my ATH-A9X, I have been looking for a worthy upgrade that will improve upon its main weakness - the narrow soundstage (as well as having just a bit more substance in the bass region - the A9X is pretty bass-shy). After some research, I narrowed it down to two cans: The Audio-Technica's own ATH-A900X, and the AKG K550.  Both of these are hailed as having very expansive soundstage for closed-cans, and both supposedly have a warm, "musical" presentation. They are reported to sound fairly similar to one another, according to several Head-Fi'ers.


While professional reviews of the AKG K550 are abundant in the English-speaking side of the world, reviews for the ATH-A900X were unfortunately very hard to find. The only two good reviews I found were the one on DigitalVersus (an European site) and one by our fellow Head-Fier, Mysteek.  Impressed by the sound frequency measurements posted by DigitalVersus, I ordered a pair of A900X from a Japanese merchant on Amazon.


While waiting on the A900X to arrive, I noticed a few "comparison reviews" between it and the AKG K550 here on Head-Fi, most of which favored the K550. But opinions regarding K550's sound quality varies very drastically, and since sound is such a subjective experience, I decided the best way to determine for myself whether or not the K550 truly is superior in every way to the A900X is to listen to both of them.


So, having found a good deal for an used pair of K550 on Amazon, I placed my order.


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3. Objective of This Review:


The most detailed comparison review done for the A900X and K550 was written by Katun, whose neutrality I personally found questionable (not just the kind of word choices used in the review, but the attitude toward a few people who disagreed with his assessment).


That said, there's nothing more subjective than asking someone what "sounds good" when it comes to audio equipment - not only do people's tastes differ, but I suspect people's hearing ability also vary greatly - for example, I sometimes wonder if bassheads have poor bass perception, which is why they need their bass boosted that much... tongue.gif Okay that was a bit rude, for which I apologize.  But in all seriousness, it is very possible that people who listen to bass-heavy music on bass-heavy equipments all the time suffer from hearing degradation, which affects their subjective listening assessments.  This is why when I look at professional reviews, I like ones that are accompanied by graphs of actual measurements.


While I have no measuring equipments on hand, my hearing should be fairly "undamaged" (I don't typically listen to music very loud, and I am very sensitive to both sharp treble and loud bass), so my goal is to (hopefully) provide a neutral, unbiased assessment of the aforementioned headphones - not just by my listening experience alone, but by comparing them against the various reviews of them, both on the forum and on professional sites, and see if there are any consensus (to ensure that it's not "just me" that's arriving at these conclusions).


If you have either the A900X or the K550 on hand, and have a measuring equipment that can confirm my analysis, that would be great!  For now, I will be attaching the frequency response graphs from Golden Ears in my comparison.


~ ~ ~ ~ ~


4. Burn-in Status:


Both cans are fully burnt-in for this review (100+ hours); I now own both cans for over a month now.


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5. The Scoring System:


I will be using a scoring scheme to assign points to the "winner" in each category (between the A900X and K550).  The score listed at the end of each category is the number of points assigned for that category only - the total number of points will be tallied at the end of the review. The old ATH-A9X will also be mentioned for comparison, but it will not be participating in the "match" since it's an old model that nobody likely owns in the U.S. and Europe anyway.


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6. The Review:


I. Packaging & Presentation:


Audio-Technica ATH-A900X: The A900X comes in a fairly subtle and classy paper box. The kind of cardboard used on the packaging isn't as thick and sturdy as those used on the AKG packaging, but it doesn't really hurt the presentation. What does hurt the presentation of the A900X a little is the plastic piece that held the headphone in place and kept the cups separated - it's made of thin and cheap plastic and looks a bit tacky in context of the otherwise excellent packaging.

AKG K550: The K550 has a stronger, more aesthetically-pleasing presentation in my opinion. The box is made of very heavy duty, thick cardboard that is surprisingly hefty. The plastic holder is covered by a layer of velvet finish, which lends a strong sense of elegance and class. While the packaging of the A900X is not shabby in any way, it lacks the same kind of presence K550's packaging has. Opening the K550 is akin to unwrapping a piece of expensive jewelry. This round goes to AKG.


Score: A900X - 0, K550 - 1

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II. Design, Aesthetics, Materials, & Craftsmanship:


Audio-Technica ATH-A900X:

  • The A900X is not a pair of bad-looking cans by any means, but it also doesn't look extraordinary. It just doesn't stand out as something classy or luxurious. I don't love it, I don't hate it. It's better-looking than its predecessor, the ATH-A900, at least.
  • I don't have any complaints about the craftsmanship of A900X - it's well-designed and constructed, and though I wished for a bit more metal than plastic on the frames, the plastic doesn't look or feel cheap. These looks like sturdy and durable cans.
  • One particular thing that Katun complained about repeatedly was the "poor quality" of the wings on A900X. I took extra effort to look into this issue, and did not personally find his claims to be true. Below are my observations:
  1. On the old, old model like the A9X, the wings only pivot in one direction (let's call it the Y-axis), which is up and down.
  2. On the A900, AT implemented the "3D Wings" which pivot in two directions (X- and Y-). The way they achieved this is by making the wings themselves into a 2-piece design - there's an "outer ring" that pivots around the Y-axis (like the old wings), and an "inner piece" that pivots back and forth (X-axis).  This is actually a fairly intricate design and I imagine, harder to manufacture.
  3. On the A900X, AT simplified the "3D Wings" to ease manufacturing process while still retain pivots in both directions. The wings themselves are now back to a 1-piece design and pivots up and down (like the old wings on A9X), but the T-shaped joint where the wings are clipped onto the arms now pivots back and forth (in the older models, the joint is fixed). This new system is slightly looser, giving the appearance of flimsily-build wings, but I personally don't find the design or construction to be lacking in quality.
  • That said, materials used on the A900X could have been better. I read in a Head-Fi post saying that A900X's stock earpads are the same as the A1000/A900Ti, but that is not true (because I just replaced my A9X pads with the A1000 pads, and I am 100% certain they are better quality than the A900X). The pleather used on the A900X earpads are of a cheaper, stiffer material - similar to the kind used on the Superlux HD668b. The headband's wings still use fabric padding, while my old ATH-A9X has pleather padding (which feels more classy). I feel like in the materials department, the A900X sits squarely between the A900 and the A9X - definitely a step up from A900, but not quite back to the glory days of A9X.
  • One design nitpick - the audio plug used on the A900X is the exact same one used by the A9X; while it isn't bad-looking, it is a bit outdated in style, lacks elegance, and doesn't blend with the design of the A900X. Audio-Technica really needs to update this on their next product cycle for the Art Monitor series.


Audio-Technica ATH-A9X:

  • In comparison to the A900X, the A9X is a lot more eye-catching. It's a bit "out there" in terms of design, but imagine seeing these cans back in the mid-90's - they must have looked sharp.
  • In terms of craftsmanship, the A9X is on the same level as A900X. It's very sturdy, though to be fair, it has less moving parts (the cups don't pivot vertically, and the wings don't tilt in both directions)
  • The materials used on the A9X is superior to the A900X. The stock earpads used the same kind of soft, supple pleather as the A1000/A900Ti pads. The padded wings are enclosed in thick, durable pleather as well (mine hasn't cracked after 10 years), which just looks better and blend in with the earpads when the headphones aren't in use.
  • The fabric used on the audio cable is the same as on the A900X, but it's colored a deep brown to match the color of A9X's frame. It looks gorgeous, and more classy than A900X's black cord (which can easily be mistaken for a typical plastic cable if not examined closely)


AKG K550:

  • Oh my goodness... where to even start. I am sure I am not the only one who was blown away by the design and aesthetic value of these cans. The K550 is hands-down one of the most beautiful set of headphones I've ever laid my eyes on (right up there with my favorite AT woodies).  All the lines just melt into one another... a true work of art. AKG wins out by a huge margin here.
  • Craftsmanship on the K550 is good - that is, as far as I can tell (there are complaints about the swivel mechanism snapping easily because it's simply glued-on, and the headband seems to be very loose in general and lacks clamping force. This I observed as well). One thing I did immediately notice was that the swivel mechanisms are fairly stiff, and therefore the position of the cups tend to "stick", and often don't conform to the contours of the wearer's head automatically when worn. The headband is fairly loose and does not provide a lot of clamping force, which doesn't help the problem.  This, I suspect, is the reason a lot of people have trouble achieving good seal on the K550. What the user needs to do is center the cups before putting them on, or at least adjust them after you put them on so they are flat against the sides of your head. Otherwise, I can find no issues with the craftsmanship here... I'll call this a tie between AKG and Audio-Technica.
  • When it comes to materials, I cannot be happier with the K550. The cups and frames are almost entirely metal, so is the headband. The type of pleather used on the earcups and the headband are top-notch, and the type of padding used for them also feels very good - they feel like high-quality memory foam rather than the regular type of "cheap" foam used by most headphone earpads. Lastly, the audio plugs on the K550 are simply gorgeous - AKG spared no expense at making the K550 look and feel luxurious. AKG easily scores a victory here again.
  • One material nitpick - the plastic used for the signal cord, while fairly high-quality, is still more prone to tangle and deform in comparison to Audio-Technica's fabric-wrapped cords, which retain their shape very well. Not going to discount AKG here though.


Score: A900X - 0, K550 - 2

(Two points awarded to AKG for winning "Aesthetics" and "Materials"; no points awarded to "Craftsmanship" due to a tie)

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III. Comfort & Isolation:


Audio-Technica ATH-A900X:

  • While a lot of people have reported comfort issues concerning the A900X (specifically due to the wings system), I personally found it to be the more comfortable of the two. The wings do not put pressure on the top of my head at all - to the point I often forget that I am wearing anything. The headband also provides a very strong clamping force - these cans do not slide around on my head at all. Audio-Technica scores a win in this one (for me).
  • Isolation is pretty good; these cans seal very easily and very well (thanks to strong clamping force).


Audio-Technica ATH-A9X:

  • The A9X is actually more comfortable than the A900X in my opinion - it has less clamping force than the A900X, and is therefore more comfortable for prolonged use. The downforce provided by the wings are a bit stronger than that of A900X.
  • Isolation is the same as A900X.


AKG K550:

  • The headband on the K550 does not provide much clamping force at all - and that's coming from someone with a big head (the headband settings are at 11 on both sides). While this makes the cups very comfortable around the ears, it also means most of the weight press down on the top of my head.  While the headband is very well-padded on the K550, it does still exert enough pressure for me to constantly realize that I am wearing something on my head. The lack of clamping force actually allows the K550 to slide around slightly when I lower my head. Considering how many complaints regarding this the K550 has received in its own Appreciation Thread, I think it's safe to let Audio-Technica win this one.
  • Due to aforementioned issue with the cup joints being too stiff (as well as lack of clamping force), isolation can be an issue if you don't be careful about achieving proper seal.  Once fully sealed, however, the AKG seems to provide slightly better isolation. The difference isn't big, but I'll let AKG walk away with this one.


Score: A900X - 1, K550 - 1

(AT wins comfort, AKG wins isolation)

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IV. Sound Quality:


While most comparison reviews regard the A900X and K550 as similar-sounding (with K550 being better overall), I have to strongly disagree with these reviews. These two cans, to me, sound significantly different from one another - to the point where it's no longer apple-to-apple. It's most definitely apple-to-orange to my ears. This was actually rather shocking to me, because I expected very similar presentation with minute differences.


Audio-Technica ATH-A900X:

  • Treble: Personally, I think the A900X easily wins the treble presentation. There are a lot more details in the treble compared to K550 - I think the main reason is because the treble is significantly rolled-off above 15KHz on the K550, while the A900X doesn't roll-off until close to 20KHz. I know human hearing isn't very sensitive above 16KHz or so, but the difference is definitely there. Another reason may be the K550's upper-mids/lower treble is way too bright and energetic, thus burying the details in the upper registers. A lot of subtle instrument textures come out easily on the A900X but are barely audible on the K550. But do not mistake A900X's treble as sharp or sibilant - because it's not. I actually hear a lot more sibilance on the K550 (details discussed under K550's section) - a good test track is Phil Collins' Two Worlds: hardly sibilant on A900X, very sharp and unpleasant on the K550. The overall treble presentation on the A900X is lively, sparkly, without being sharp or sibilant. Just the perfect balance for me - beautiful, beautiful treble.
  • Mid-Range: It was interesting to see how many other comparison reviews claim that K550 has a warmer, more lively presentation, because the moment I tried out both cans I experienced the exact opposite. The mids on A900X are significantly more pronounced and warmer than those of the K550, especially in the lower-mids, where the K550 has a recess. This results in the A900X's sound having a lot more body (the perceived difference for me is bigger than the frequency response graphs may show). According to the frequency response graphs, while A900X's mids response is fairly linear (except for the down slope in the upper-mids), K550 has a dimple around 500Hz, and its overall mid-range response is more jagged / not as linear. The down slope in the upper-mids also helps A900X's lower- and mid-registers sound much more hefty and robust. Vocals sound more intimate, full, rich, and lively on the A900X. Orchestral instruments have both intimacy and presence. Personally, I prefer the mids on A900X; it sounds a lot more natural to me. Another point to Audio-Technica.
  • Bass: The bass is my only issue with A900X's sound presentation. The extension in the sub-bass, while present, isn't pronounced like on the K550 (the one thing about K550 that I really really like). Also, there's a fairly wide peak between 50-250Hz, which makes music drony/boomy to my ears. Instruments that have a lot of both bass as well as lower-mids (such as cello) tends to have their mids drowned out by the bass, which is very unfortunate. I have tried EQing out the peak on the A900X and indeed, all the details in the lower-mids immediately came back. I'll admit that I am a bit of a purist in this regard and would prefer headphones to sound good without EQing or modding. Within the context of a review especially, I don't feel EQing is appropriate; these headphones simply are too bassy for my taste (without EQ), which is a shame because it has an otherwise perfectly balanced presentation in my opinion. It is possible to reduce the bass with different earpads though (see section at end of review).
  • Soundstage: The soundstage on the A900X is very wide - especially for me, coming from the (in)famously narrow A9X. Sound positioning also feels better on the A900X than the K550 - sounds are more "focused" and easier to pinpoint (I had my wife test both cans and she actually pointed this out as one of her first observations, without any prior inputs from me). Additionally, the soundstage on the A900X feels more "layered" / has more depth (more details explained under K550 soundstage section). I think the point goes to Audio-Technica here.
  • Instrument Separation: In my opinion, instrument separation is better on the A900X due to two reasons - more detailed upper-treble, and better sound positioning. Don't get me wrong, the K550 is a very clean-sounding headphone (I would argue quite a bit cleaner than the A900X), but I think its fuzzier sound stage and overly aggressive upper-mids/lower-treble hurt separation in busier tracks.


Frequency Response Graph of Audio-Technica ATH-A900X


Audio-Technica ATH-A9X:

  • Treble: The A9X is actually more similar in this regard to the K550 than the A900X. It is very soft on the treble, especially in the upper region - the details are present, but you have to listen for them. Extension isn't naturally as good as on the K550 - though the A9X's drivers are capable (need EQ boost).
  • Mid-Range: The mids on the A9X are some of the most beautiful I've heard (in my limited experience). It has that very old school Audio-Technica warmth and intimacy. I actually still like the mid-range on the A9X better than the A900X; it is fuller and more engaging, even though it doesn't have quite as much clarity - but nothing's perfect in every way. tongue.gif
  • Bass: The A9X is fairly bass-shy, but that in itself is a pleasant quality for me since I get annoyed with bass-heavy cans very easily.  The amount of bass present is more than sufficient to give orchestral instruments proper presence and impact. The quality of bass is also good - it is fast, tight, and clean. Once again, the drivers are capable - and can be EQ'd to provide appropriate bass for heavier genres like trance or techno.
  • Soundstage: The A9X has one of the narrowest sound stage you'll ever hear, I promise you! I have no idea why it was made this way, but on these cans, vocalists often sound like they are singing right next to your ears; and orchestral pieces usually sound like it was performed in a small room with you standing right in the middle, amongst all the musicians. This makes certain pieces sound very intimate, but it's also a disservice for some music. That aside, sound has good focus and positioning is good.
  • Instrument Separation: The A9X doesn't do particularly well here compared to either of the other two cans; partially due to the rolled-off treble & smooth mids. It's also possible that the older drivers on the A9X just don't offer the same kind of resolution as newer generation stuffs. That said, it doesn't really do all that bad.


AKG K550:

  • Ear Cups Placement: Okay... there's a lot of complaints in K550's appreciation thread regarding the clamping force and achieving proper seal affecting sound quality. While the K550 seals fine on my head without me having to hold the cups to my face, the K550's sound changes VERY drastically with cup positioning (as opposed to the A900X, which sounds pretty much the same regardless of whether you have the cups slightly forward, slightly back, or press them closer to your head).  The K550 sounds very thin and distant if you don't press the cups to your head after you put them on; it becomes much warmer and more full-bodied if you press the cups in.  If you move the cups forward, the mid-range is recessed but the bass comes out. If you wear the cups dead-center over your ears, the mids are more pronounced but the upper-mids get way too bright, and the bass gets buried. If you wear the cups back... well, forget it, you get the idea.  It's very hard to gauge what these headphones are supposed to sound like, as per manufacturer intended - so I am going to go with what I think is the most pleasant-sounding wearing position, which is having the cups slightly forward (the rear of the cups rest gently against the outer edges of my ears).
  • Treble: - Personally, I feel the treble is K550's weakest point. There are three issues with K550's treble presentation - the first of which is the significantly rolled-off upper-treble, which takes away quite a bit of subtle textures from instruments and vocals. The second is the overly bright upper-mids/lower-treble. As you can see in the frequency response graph, the area between 5.5-8KHz are significantly boosted on the K550, while on the A900X this region is deeply recessed. I think this is what's primarily responsible for the slightly unnatural, "plasticky" treble signature of K550 (several Head-Fi'ers attested to the unnatural treble; Tyll on InnerFidelity also mentioned it). While it might not be considered a sharp headphone in the grand scope of things, the K550 is a lot pickier with recordings than the A900X, and the excessive brightness can get fautiguing after a while, depending on what you are listening to (a lot of my J-Pop and trance collections are almost unlistenable on the K550; just way too busy in the upper-mids/lower-treble, but not enough bass and lower-mids to offset it).  The last issue with K550 is that I actually find it fairly sibilance-prone - at least, much more so than on the A900X.  And no, I don't believe the aforementioned peak in the upper-treble/lower-mids is to blame. I suspect the actual culprit for K550's sibilant tendencies lie in the small - but rather pronounced - peak at 12KHz, where the A900X already pushed its treble back down. Overall I find K550's treble a bit disappointing; even though it's not an issue in most music I listen to, when the problems do come out, it isn't very pleasant.
  • Mid-Range: The mids on the K550 is interesting. Let's start by saying the K550 is relatively thin-sounding. Yes, the K550 is a thin-sounding headphone - this opinion has been voiced several times in various Head-Fi threads as well as professional reviews (Headfonia, Sound & Vision, just to name a few). It's not thin to the point of being unenjoyable, but compared to the A900X, the lack of upper-bass/lower-mids body is very apparent.  As you can see in the frequency response graph, there is a dimple around 500Hz. While this is what, I think, lends the K550 its clean, near-black acoustic background, I really do feel it could use a bit more lower-mids presence. Percussive instruments and male vocals often have trouble achieving their full weight on the K550 (female vocals usually sound great, however). The second issue is of course, the aforementioned upper-mids/lower-treble peak, which makes a lot of orchestral instruments sound way too bright (the best example would be trumpets). I seem to remember Tyll on InnerFidelity mentioning that a downward slope between 1-5KHz is desirable - and the K550 indeed showed this downward slope in his measurements. However, the K550 displayed no such slope in Golden Ears' measurements - with the exception of a small dimple at 4KHz, the entire mid-range is fairly flat. The A900X on the other hand displays such a downward slope in the upper-mids. Not sure what's "better" in this case - but personally I find the A900X more natural-sounding and has better timbre.
  • Bass: The bass presentation is definitely in K550's favor. I find K550's bass a lot cleaner-sounding, with much more audible extension. Looking at the frequency response graphs you can easily see why - the sub-bass region is significantly boosted whereas it is rolled off on the A900X. Since human hearing is less sensitive to sub-bass, this was probably a good tuning choice on AKG's part. I was surprised to see that K550 also has a mid-bass bump between 60-200Hz, because these cans sound a LOT less boomy than the A900X - which is a huge plus for me. The aforementioned dimple around 500Hz is probably the reason for the cleaner-sounding bass, though I am not sure.  In any case, I like K550's bass presentation a lot more than that of A900X's.
  • Soundstage: This is where I found things interesting. In terms of sheer sound stage size, I feel the K550 actually isn't quite as wide as the A900X. However, the K550 has a very interesting "spatial" quality to its sound stage. While sounds on the A900X seem to stretch out onto a 2-dimensional plane, the K550's sound stage sounds sort of airy and 3-dimensional. I suspect this has to do with whatever this "Real Image Engineering" AKG used to simulate the soundstage of open-backed headphones on these closed cans.  Personally, I like this effect - however, sounds also feel a less focused compared to A900X, and positioning takes a hit as the result. Furthermore, the K550 seems to push sounds "back" within its soundstage - for example, a vocalist who sounds like she is singing only 1 meter away on the A900X will sound like she's 5 meters away when listened to on the K550. The effect is similar to listening to sounds through speakers (which, to my understanding, is one of the qualities of open-headphones?)  Again, I do like this effect; it makes the presentation less claustrophobic and more relaxing. But it also means the K550 has trouble achieving intimacy or make things sound nearby. This issue is most apparent In movies: when objects fly past the viewer, on the A900X the proximity effect is very convincing, but not so much on the K550. This is what I meant by the A900X sounding more "layered" and has more depth - for example, listening to African vocals on the soundtrack for The Last Lions, both my wife and I can easily tell which vocalist is standing closer, and which is standing farther away. On the K550, this "depth positioning" is more difficult, because everything sounds farther away.
  • Instrument Separation: As I mentioned in the A900X section, I feel the K550 actually doesn't do as good a job at separation, despite it being cleaner-sounding and having a blacker background (paradox!). The missing details in the upper registers and its tendency to get too bright and busy in the upper-mids/lower treble are the primary culprits - and the fuzzier sound stage contributes to it.


Frequency Response Graph of AKG K550


Score: A900X - 4, K550 - 1

(AT wins treble, mids, sound stage, separation. AKG wins bass)

~ ~ ~ ~ ~


V. Total Scores & Final Verdict:


The Audio-Technica ATH-A900X and K550 both finished with 5 points - and believe me when I say this was not the intended result. I went into this review expecting two very similar-sounding pairs of cans, with K550 consistently out-classing the A900X in every way - and this was not the case at all. As you can see, the K550 won most of its points in aesthetics and materials, while A900X won most of its points in sound quality. This would indicate that A900X has superior sound quality overall.


However, this is not necessarily the case - because this is where the listener's subjectivity as well as needs come into play. Do I prefer listening to music on the A900X over the K550? Absolutely.  But would I entrust the A900X with video-editing or audio-mixing work? Probably less so. The A900X does beautify the recording a bit more, in my opinion - and the K550's cleaner sound/black background are good qualities for sound mixing.  One also needs to take overall sound balance into account - the A900X's heavy bass gives me a headache after a while; the K550, while being overly bright on occassions, doesn't have this issue. If I keep the volume down, the K550 is the less fautiguing of the two for long-term sessions.


In summary: If you like a rich, lively musical presentation that isn't overly exaggerated and sounds natural, the Audio-Technica ATH-A900X is the choice to go with. If you want a clean-sounding headphone with a fairly black background and fairly relaxed presentation (either for sound mixing or listening to slow music), then the K550 is for you. Personally I can't really recommend the K550 for general music/multimedia usage, especially not for the average user. It is simply too picky with recordings and genre.


Like I said before, apples and oranges. rolleyes.gif

~ ~ ~ ~ ~


Usage in Video Games & Movie-Watching:


Since a lot of people were wondering how these two cans compare for usages outside of music, I did some testing with both cans. And to put it simply: The A900X is much, much better for entertainment usage.


ATH-A900X: My observations in music listening tests are confirmed once more - the A900X has much better sound focus, and therefore much better sound positioning in games & movies. The perceived difference is not small, either - one particular film I love to use for testing surround effects is the anime Sky Crawlers; it has one of the best surround sound mix I've heard in any film. The aerial battle sequences sound nothing short of spectacular, and listening to it on the A900X is like having an eargasm.  The sound stage is very wide, and like I said the sound positioning is superb; you can hear all the planes circling around you and accurately pinpoint each of their individual location within the soundscape. Another movie that had very audible difference in sound positioning for me is Summer Wars, in a scene when a bunch of books were falling down from the shelves - you can hear the books land all around you on the A900X, but on the K550 the positioning just sound kind of fuzzy and indistinct  Lastly, the boosted bass on the A900X, while an annoyance in some music, serves movies & games very well here. Car engines and airplanes have that proper weight and roar; gunshots and explosions have tremendous impact.


K550: The K550 is simply not that ideal for movies and video game usage. I am not saying they are bad for such purposes - I just watched Jurassic Park on them and they sounded fabulous. But the aforementioned "airy" and "3-dimensional' soundstage creates some issues with sound positioning/focus, and the "thin" mids on the K550 make things like car engines and machine gun fire sound overly bright and "hollow" (since there's no meaty bass or lower-mids to give these sound effects weight and presence, and the aggressive upper-mids/lower-treble contributes to this issue). To help you understand what a big difference this makes: A machine gun that goes "tuk-tuk-tuk-tuk-tuk" on the A900X sounds like "tak-tak-tak-tak-tak" on the K550.


So if you are looking for closed-back headphones for games & movies, the A900X is simply the far more ideal choice.

~ ~ ~ ~ ~


ATH-A900X Earpads Replacement


I ended up doing a little tweak to the ATH-A900X since I wanted them to be less bassy, and it turned out the solution was staring me in the face. :)


I was looking at my ATH-A9X and the ATH-A900X side-by-side.  My A9X has the A1000 pads installed (which is similar in shape and material to its stock pads; it has better pleather than the A900X pads). The A1000 pads has oval opening, while the A900X pads have round opening (which makes the holes a lot bigger).


Bigger holes = more trapped air = more bass.


Since the A9X is bass-shy, and the A900X is too bassy, I came to the sudden realization: Why didn't I think of swapping their pads???


The ATH-A9X with ATH-A900X earpads installed.




The ATH-A900X with ATH-A1000 earpads installed.


The result? Fantastic! :)  The A900X is no longer droning whenever there's even the slightest bass present; the bass no longer bleeds into the mids and I can actually hear the sub-bass extension now. xD The A9X on the other hand received a bass boost - still far from as bassy as the A900X, but since the A9X doesn't even have D.A.D.S., to expect otherwise would be silly.


The A900X is very clearly superior in every way to the A9X - much better treble, much better bass, and much much better sound stage and positioning.  Aside from the subpar stock earpads, I really can't complain.


So, A1000 pads on A900X - simple and highly recommended mod!  Not only does it clean up the bass, but the pleather is a lot softer, more supple, and hugs the face better (which helps reduce sliding - especially if you have issues with the wings). So it's both a comfort & sound quality mod. :)


Pros: Sound, Overall quality, Comfort, Closed-back but they don't sound like it, Bang for the buck

Cons: Non-removable cable, Cable is very long (3m), Can be hard to drive from small devices, not recommended for small heads because of sealing issues

This a review, as well as bit of a comparison to the Focal Spirit One, as those are the last headphones I owned and I absolutely loved them. 

Man, where to start with these; right off the bat let me tell you that I absolutely love them. They are totally different from the Spirit One, and in a very positive way. When I first got the 550's, I was surprised at how heavy the box is. Now to anyone who thinks you get a lot of accessories with the K550's, I have to disappoint you. All you get are the headphones and a quarter inch adapter, the latter of which is gold plated and screws on top of your cable. Everything about the headphones exudes quality, which couldn't be said about my Spirit Ones, as their headband and joints are made only of plastic, and thus cracked under my big head. The 550's cable is not removable and it is 3 meters long. That's definetly something to keep in mind. Alternatively, you could go with K551, which have a detachable cable. Me, I just couldn't justify the hefty price difference between the two.


When you put the K550's on your head, there are two things you immediately notice (coming from Spirit Ones): Man, there things are huge! And; Man these things are comfortable! Seriously, comfort is insanely good, which once again can't be said for the S1.
I don't know if I would take these out in the public though, as they are quite big and the cable is looooooong for mobile use. 


Enough of the chatter now, and let's get to the sound :)

I listen to music through the following setup: 
-HP Envy 17 Laptop with FLAC's or Spotify- FiiO E07-K Andes USB DAC/amp (To bypass the HORRID beats audio on the laptop, that RUINS anything connected to it)- AKG K550

When I first started listening, I noticed that you absolutely need a good seal with these headphones, in order to enjoy them. For me, that's easy. But for anyone with small heads, and/or women, this might be a real issue. Try not to buy them blind like I did, and try them in a store to see if they fit. Once I found the perfect seal, I was amazed at how much bass there was. Compared to the Focal, which are said to have a lot of bass, I was really surprised because the AKG have more of it. The bass is deep and very well extended into the sub-bass range. It also never sounds boomy or muffled, nor is there too much of it. 
Next, I wanna mention the soundstage: WOW, do they sound different than anything I've owned before, even though they are closed as well. They sound very similar to the K701, which I had the pleasure of testing. Instrument separation is excellent, and there is no "overlapping" of treble sounds, like I've noticed in the Focal. Mids are not as warm as the Focals' and overall, the K550 sound more detailed and technical, while the Spirit One are very warm and love vocals. Not to say that the AKG's don't, it's just a different kind of love :) . (The upper mids can sound a little (too) prominent at times)
Now for the highs, as they were the most notable change for me in comparison to the Focal; they are a lot more prominent and not rolled off, especially in the lower to mid-highs. They provide a nice amount of sparkle and excitement in my opinion, but sometimes at a cost: The 550's are kind of "unforgiving" when it comes to older recordings and lower bitrates. They will bring out every imperfection in the sound and can thus produce hissing and siblances. This was notable on older rock/metal recordings or such that weren't perfectly mastered, which is most of them. (Dream Theaters older albums are an example here).

Overall, I'd call the sound open, pleasent and enjoyable. 


Should you buy these headphones? -Absolutely. That is, if you can find a good seal, and you don't plan taking these on your commute every morning. The great sound, quality and comfort, as well as the the awesome bang-for-buck ratio are reason enough to buy them. But for small heads, and a closed portable, I'd still favor the Spirit One.


Pros: Sound, Fit, Style

Cons: Ears Can Get Sore

I've constantly said I wanted to try these.

I've seen the price tag stay at $200, and it's appropriate.

It's big, but has elements.

It's sound is stand out, Class A, $200 Sound.


The AKG K550

I've been wanting to try these since I seen the price tag, after searching for an upgrade, looking at the MDR-7506, and seeing these side by side, the MDR-7506 is OK, but has a purpose. It's a Studio Monitor, that's it's justice.

The AKG K550 is an important piece in it's price range, and it reminds us as the why the M50 lost it's reputation.


I finally got a chance to borrow these.


Let's discuss.

Build Quality:

- To one who can appreciate, is to one who's more likely to fall more in love.

Those are definitely words to live by when looking at this as a beginner headphone. 

It's a big headphone.

- She's built like a brick house.

Not to be confused with the song, but the headphone is heavily proportioned, and has a beautiful slick look, also durable... more durable than most.


Easily put, it's a headphone that for it's price, though not a Studio Monitor, it's built to take a beating like one.



We aren't going to get into Highs, Mids, & Lows, but we'll discuss this sound signature widely.


My impression of the sound at first was that it had an artificial sound to it.


Be It This Is A Sub-Open Back Design by sound.

The Soundstage is a bit awkward though. I'd compare if to being in a square shaped room, and telling everyone to face their corner and begin to play.


This created a mere echo in the vocal signature, quite disturbing, but after some burn in the sound smoothed out, but remained to sound in that pitch.

The Bass is VERY FULL, TIGHT, & COLORFUL, it's full of character. I can't say that there's even a true sound for the Bass. 


That said, this headphone will kindly fit any genre, and is polite to Hip Hop, & Rap for a change.

I think after seeing that this didn't budge much with Rap based genres I found my disappointment.

Techno, House, & other Electric genres lacked clear detailing, they weren't as vibrant, and you didn't feel like you were getting to experience the vibrations and clicking that some people find in these genres.



On my last bit of information, I think with the things this can has to offer, it's the best in it's range if you aren't looking for a Studio Monitor.

It's unique, and I would also argue, if you're not used to Warm, or Cold Sounding signatures, and don't wanna jump into a random experience, this is perfect for the job.

I didn't find a genuine sound fit to this, it never had a too Bright sound, it wasn't ever truthfully relaxed, and the Bass notes, undertones, and playbacks weren't Warm sounding.

It's mixed, almost giving you a hollow type of sound.


Pros: Comfort, Isolation, Balance, Detail

Cons: Nothing at this price.

Been a while since I bought some new headphones. The HD800's put an end to that for the last couple of years... But I wanted some closed back for certain times and so snapped these up. 


The balance of these is very good indeed, as is the tone. The AKG sound in a closed back pretty much. More midcentric than the KXXX with a closer image - slightly warmer but still with plenty of bite at the top. I'm impressed with the isolation as well- wasn't expecting too much - I wear glasses and I still get a very good seal. The comfort of the pads is another plus- very soft. 


The mid frequencies are much better on these than the KXXX and this is most welcome. (no nasty peak at 4k)


I wouldn't normally recommend any closed back hp for classical music but these sound great. Obviously not as airy as their older open back brothers, but the imaging is very focused and certainly open enough for large scale orchestral works. The detail retrieval is on par with the KXXX imo, only a little more more smeared at the lower end. 


I would describe the sound sig as typically AKG - 'dry' apart from the warm bottom end. I've read a few reviews that describe these as sounding more like an open headphone. They do have an ample soundstage for closed but they still sound like a closed headphone.  


Yup, an absolute bargain for what they are going for these days!   


Pros: Clear high band, acceptable mid tone

Cons: Absolute lack of bass

Well, the infamous K550 was there. Big, comfort at an incredible price. I had to wait for one week before I got mine so I put it on.

Absolutely better than K701 I had a while ago. However, the overall quality is killed by zero presence of the bass. Where have they gone?


Pros: Spacious - for closed back. Non-fatiguing, easy going sound. Work surprisingly well with iPhone.

Cons: No better than a reasonable £30 pair of open back 'phones.

I tried these with a Benchmark DAC1, a Fiio X3, a Fiio X1+E17 and various lesser devices including an iPhone. They seem pretty easy to drive. Music was a mixture of classical and Jazz - both CD quality and HiRes. 


My value rating is based on the £107 I actually paid from Amazon. I am having to keep reminding myself how cheap they now are in order to give them much praise though. I guess the heavy discounting of these should have told me that they were not that special.I would certainly have been pretty pis**d if I had paid full price.


Their best attribute is a surprisingly spacious presentation - about as good as a cheapish pair of open 'phones. To me they didn't sound any better than my £30 Jays-vJAYS except, for some reason with an iPhone. There seems to be some sort of synergy going on with the iPhone and they made it sound better than I have ever heard it. IF the iPhone was my sound source I would have been very pleased with the K550's but it isn't, so I'm not. They have a pretty laid-back relaxed presentation without any intrusive exaggeration but also without clearly presenting the fine nuances that you can always hear in real life (musicians breathing, fingers sliding on strings, valves clacking, scores being tuned, chairs squeaking etc). IF you can get them comfortable, they would probably be OK for long-term, relaxing listening but if you are trying to listen carefully, they just don't deliver.


Although huge, they don't actually look too silly when on your head. It is difficult not to think of Dr Who and the Cyber-men though.  They feel fairly robust and appear well made but I don't find them comfortable. I have no problem with head-squeezing or seal - that's all works just fine for my head. My problem is that the padding on the top of my head just doesn't protect me. After a few minutes I am uncomfortably aware of the weight pressing  down on the top of my skull. Easily cured with a bit of foam padding but do you really want to do that..........


For £107 they are pretty good value for CLOSED 'phones but in no way exceptional - unless you use an iPhone.


Pros: Non-overwhelming bass, detailed vocals, great soundstage

Cons: Can't find yet

Excelllent headphones, coming after ss 9h headset, senn's 429 558 598 and i love these most, i differentiate details better in vocals now, i can say if vocalist is blowing into microphone while singing, there are more details in vocals which i cannot explain in english,  coz i'm not good at this section in english. Bass is not overwhelming, it is what i like most, not muffled, also if you EQ the bass it will sound much better as it did on my nokia with eq presets. Priority is for home use, but it's perfect using outside with phone, cable thickness is not the problem, as you can roll it around the phone, and put everything in the pocket without all stuff sticking out too ugly.


So much better in games with hearing steps detailed, soundstage is right as i wanted, with 9H i wanted to hear games world better/wider than i heard, akg550 fills this hunger, love it. Orientation in fps games maps is very good right now for me.


Pros: imaging, clean sound

Cons: no carrying case included

I have been using AKG K550 for past few weeks and enjoying them pretty well. This is my first foray into mid fi and I think its a solid contender for getting into mid fi sound especially as it has very low barrier for entry (whole setup). I am driving it with Audinst hud mini, entry level dac/amp and it drives it with authority and good clarity.


I have been using Sennheiser HD518 extensively, and have auditioned HD595 as well as HD650 before this. So thats my reference point here as HD5XX series is rather popular and what you can expect to get if you go for K550.


First some sound signature differences between sennheiser and akg. k550 requires you to be engaged to music instead of being half asleep to enjoy. k550 has this comparatively thin sound that changes very fast according to notes being played, thus conveys note level information with much more clarity. this clarity improves dramatically in hd650 but still k550 is clearer. For me, I need to actively listen to music and be engaged to enjoy k550.


So is one inherently better than other? I don't think so. both sounds are usable according to mood. (its not that I am feeling sleepy all the time, so why Sennheiser only collection?)


So now about K550. First some observations about K550 that are striking:


Great isolation without any clamping pressure whatsoever. No seal issue for me. I would attribute this to ear pad material. Its most certainly is something special that blocks sound very well. It must be in contact with your skin to achieve seal.


Very forgiving for low bit rate material. my much lower hd518 is almost un listenable out of phone with lower bit rate tracks as I could see some holes in music. k550 polishes it and makes it listenable, I think. It might have something to do k550 being easy to drive, not sure why it does that.


Very clean sound. no grain whatsoever. hud mini is inherently grainy and with grainy old recordings of the old like led zeppelin, it was almost un listenable on hd518. (all three recording, dac/amp, headphone are grainy making too much of it). on k550 its pristine.


Now I would describe frequency response a bit:


Bass: awesome. Goes very deep, is tight and reasonably textured. Exactly what I wanted.


Mids: Rich, detailed, not upfront. very enjoyable.


Treble: Now I am terrified of sibilance or bright sound. But k550 sounds exactly like I wanted it to. I don't think its dark sounding, but its got this peculiar way of doing treble. Treble extension is good but detail is very less thus to my ears sounds perfect. (better safe than sorry. won't cut any points here cause of my preference. I am looking for enjoyable headphones than perfect ones).


A word on soundstage:


Good sized. Its a closed headphone and has good width and depth with that limitation. Most impressive part has to be imaging. Pin point imaging if its present in recording, even if two same instruments are playing, it places them very well in sound stage.


Comfort is very good as it exerts very little pressure on head, but as its a sealed design, it gets sweaty. Ear pads don't allow a lot of breathing.


Build quality is good mixture of metal and plastic. not built like tanks and I intend to take good care of them. especially i don't want to change alignment of cups and thus affecting seal.


All these things make them a worth can but what makes them 5/5 special is, well they are very enjoyable. Even with their relatively thin sound, they have this deep and satisfying bass thus make for a very convincing presentation. Their sound stage is wide but they don't have diffused presentation like my HD518 that renders each component of music completely separate. Instead it presents a good mix of music, instruments often inter lapping but still sounding separate with note level detail, harmonious with each other. If you think about it, that is how you hear music when in a hall with musicians. Not completely separate from each other.

AKG K 550

With the K 550s, AKG engineers have struck a masterful balance between the noise-isolating qualities of closed-back headphones and the spacious, dimensional sound of an open-back design – creating reference-class headphones ideal for private listening both at home and on the go. 50mm drivers, the largest in our product line, deliver great AKG sound from your hi-fi system or virtually any portable device. The large ear cups and new headband design ensure an amazingly comfortable fit, and the 2D-axis mechanism folds flat to stow or go. Acoustic Seal: Closed Driver Type: Dynamic Ear Coupler Type: Full-Size Coupler Size: Large Cord Type: Straight Left-Side Cord Length: 9.5ft Detachable Cable: No Impedance @ 1kHz: 32 Ohms Isolation: -12dB ~ -18dB Weight: 305 grams w/o cord Connector Type: 1/8 Headphone Type: Full Size Manufacturer Warranty: 2 years Sensitivity: 114 dB

Model Name/TypeMPNEAN/UPC
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