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[Comparison Review] AKG K550 & Audio Technical ATH-A900X

A Review On: AKG K 550

AKG K 550

Rated # 31 in Over-Ear
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Price paid: $230.00
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Pros: Excellent bass extension & mid-range clarity. Smooth & grain-free treble. Spacious soundstage.

Cons: Treble rolls off a bit early. Lower-treble a bit too forward. Mid-range and bass could both use some additional body. Sound imaging a bit indistinct.

Comparison Review: ATH-A900X, AKG K550 


This is the third major update to this review. I have now spent two years with these headphones and am intimately familiar with their sonic qualities (no more "I think/I feel" in my conclusions). I cleaned up the review significantly and trimmed off the fat. The review now focuses on just the ATH-A900X and the K550, and refers to the A9X and K553 in brief comparisons only (I have written separate reviews for those cans).


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Packaging & Presentation 


Audio-Technica ATH-A900X: The A900X comes packed in a simple cardboard box with a plastic holder. It's not distasteful but not particularly elegant either. I personally find it a bit cheap-feeling. One might argue that packaging is the least important aspect, but considering $200+ is significantly more than how much the average consumer would spend on headphones, I feel a bit more of a luxurious treatment could really help.

AKG K550: The K550 is packaged in a very hefty and sturdy cardboard box. The holder, though plastic, is covered in soft black velvet. The whole package feels like a expensive piece of jewelry or a work of art - and given the K550's design direction, one shouldn't be surprised: This headphone is an artistic statement. I personally think AKG did a much better job here.


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Materials & Craftsmanship 


Audio-Technica ATH-A900X

  • The A900X is a good-looking pair of headphones. It doesn't have the "flash" of the A9X, but it definitely looks classier than the A900 that preceded it. Comfort level is very good and I in fact prefer it over the K550 in this department - the angled drivers on the AT do not press against my ears, unlike on the K550, and clamping force is more adequate in my opinion.
  • Construction appears to be solid and durable. Nothing felt loose or flimsy, and the plastic bits seem to be high quality with no rough seams.
  • One particular thing another reviewer complained about was the "poor quality" of the wings on the A900X. I looked into this issue, and did not personally find this to be true (relative to previous models). Below are my observations:
    • On the old model A9X/7X/5X, the wings only pivot in one direction (let's call it the Y-axis), which is up and down.
    • 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 rim" 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.
    • 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, this joint is fixed). The joint on the new system makes the wings feel loose, giving the appearance of flimsiness, but having owned this headphone for two years I can attest that the construction quality on the wings are solid.
  • Material quality on the A900X is decent but not great. It's a step up from the A900 (which had the cheapest pleather possible and several plastic bits just look like sub-$100 headphones), but it's not at the same level as its older cousin, the A9X (which had supple protein leather earpads and wings). The earpads on the A900X is a durable-looking pleather that feels a bit on the hard side, and the wings remain fabric-covered like on thd A900.
  • One nitpick: The stereo plug on the A900X is the exact same one AT has been using since the mid-90's (starting with the old ATH-AX series). It might have looked ok in the 90's, but looks a bit gaudy by today's more understated aesthetics.





AKG K550

  • I consider the K550 one of the most beautiful and tastefully designed product (not just headphones) I've seen. The construction, materials, and appearance are all superb. The earpads and headband are of very high-quality and supple protein leather. The headband markings are beautifully etched on rather than painted. Even the stereo plus is meticulously designed to look like a luxury item.
  • Comfort level is good but there are some nitpicks here... The earpads could be a bit deeper. The top of my ears do press against the drivers because the foam used in the earpads are extremely soft. The earcups are a bit stiff when it comes to pivoting, so they may not conform to the shape of your head without manual adjustment. The clamping force of the headband feels a bit loose, especially if you have small heads (and this is a headphobe that already has sealing issues)
  • 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 better. I personally prefer AT's implementation.
  • One material nitpick... The headband padding is pasted onto the headband using basically a double-sided tape. Unfortunately the adhesive becomes a black goop as it ages and, in my case, actually started oozing out from the headband and making a mess on whatever surface I leave the headphone on. I ended up tearing out the padding, cleaned off all the adhesive, then glued it back using a glue gun.


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Sound Quality 


Several Head-Fiers have claimed that the A900X and K550 are tonally similar. This can't be further from the truth, heh. These are very different-sounding cans.


Audio-Technica ATH-A900X

  • Treble: The A900X has a fairly clear and resolving treble. It's quite sparkly and lively without being offensive or sibilant (the lower treble is recessed on these cans to reduce sibilance). Extension is absolutely brilliant, going fully up to 20KHz. The only complaint I have is that it's very noticeably grainy-sounding compared to the K550, whose treble is absolutely silky-smooth.
  • Mid-Range: The A900X has a sweet, thick mid-range supplemented by full upper bass/lower-mids. It's warmer than neutral, but I wouldn't say it sounds too colored. In comparison the K550 sounds rather thin and less musical. All that said, mid-range clarity is not nearly as good as the K550, which has a near-black background and is significantly cleaner-sounding.
  • Bass: The bass is my biggest gripe with the A900X - there's quite a bit of mid-bass bloat and the control isn't particularly tight. Bass extension isn't very good either - the rolloff starts at 50Hz, which means there's not much sub-bass compared to the excellent extension of the K550.
  • Soundstage: The A900X has a very wide sound stage, likely owing to its excellently-resolving treble. Imaging is likewise excellent - I feel this is one area where it has a definite upper hand against the K550, whose soundstage - while large - feels a bit indistinct.



AKG K550

  • Treble: The treble is a bit of a problem area for the K550. Many users have complained about it being "peaky" or "sibilant". I don't find it offensive overall, though the lower-treble is a bit too forward, causing the slightly unnatural treble presentation noted by many reviewers (a problem compounded by the thin-sounding mid-range. Both issues were addressed in the K553). I also wish there were less roll-off in the higher octaves, as the K550 could benefit from a better extension (it's rolled off from 1.5KHz onward). Complaints aside, treble clarity is decent and I do like how amazingly smooth the treble texture is. There is absolutely no grain on the K550.
  • Mid-Range: The mid-range on the K550 has excellent clarity, which I really love. However it is sometimes dominated by the lower-treble, which as I mentioned, is too forward. Additionally it could use some additional body - the upper-bass/lower-mids region feels a bit recessed.
  • Bass: The bass on K550 has excellent tightness and extension, however it could likewise benefit from some additional body. A 2-3dB boost in the mid-bass would provide a more balanced bass presentation (exactly what the K553 did).
  • Soundstage: The K550 is well-known for its spacious soundstage, and I do agree it feels very wide and airy. However, I feel the imaging is a bit fuzzy and indistinct. Watching movies and playing games, it's much easier to tell where a sound is coming from on the A900X.



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Final Thoughts 

The A900X and K550 are both good headphones with distinct personalities. Neither are perfect, though. The A900X is definitely the more musical of the two thanks to its overall fuller and warmer tonality, and its accentuated mid-bass makes it more ideal for games and movies.


The K550 is much cleaner and analytical-sounding, and with the exception of the lower-treble issue, is the more ideal of the two for professional applications.


very great review :D
Just got the a900x last week and have had K551 for about a month. One thing I noticed immediately is the sound stage on the a900x is much better than the 551. The a900x also has a lot more resolution than the K551. a900x sound stage is deeper, more three dimensional but not fuzzy or blurry at all compared to the K551. Positioning of instruments is easier to hear for me. On busy passages of music the a900x manages to maintain separation and detail in instruments where the K551 misses things all together. The K551 is not bad by any means and in this price range I'm very surprised to find something (a900x) that I consider an upgrade and not a side grade.
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