Airy sound from stinking material - * Addendum: Poor Support

To equal "stink" to respond to the popular topic: Yes, the K550 stinks and indeed toxic. Even more on the second day of this poisonous plastic odor leads to a slight headache and dry airways. And that's no exaggeration. Here a very unfavorable formulation was used. AKG should act as quickly as possible. For this reason I will namely the headphones send back. And that is why I have withdrawn him two star and confronted the AKG support with this problem. An answer will hopefully follow in the next few days.

The sound, however, is worth all five stars.
The K550 is a, for a closed headphone, very three-dimensional and airy sound again, with wide stereo stage. He is tuned neutral and very transparent. Often come concerns a reading from "neutral" and "transparent", the headphones could play too little bass. However, this is not the case with the K550. His bass response seems linear hinabzureichen to 20Hz without prematurely to experience a setback. Linearly as it goes to the middle to the lower heights on. It was not until the mid-levels, he makes a little bend and can thus the frequency response very pleasant and can still sound fresh. From the upper heights he rises up again something that you can recognize the good auszumachenen high frequency details.
The K550 never sounds hard, never too lax and never to oversized bass. With beautiful portioned pressure in the deep bass and snapping drum beats he sounds nice rousing. However, it does not spoil his listeners with showmanship. He always sounds clean and contoured. In treble but a Beyerdynamic DT990 on the other hand sounds glistening, somewhat more detailed and naughty. The AKG provides in this area a bit cleaner, more pleasant presentation.
The center resolution is exemplary and can purely miss nothing. Singing voices sound undiscolored, flourishing without excessive sibilance. Of course, the overall sound is overall somewhat denser than the open Beyerdynamic DT990, however, the K550 has the minimally precise and more powerful bass without the low-mid to superimpose it.

The comfort is very good. The pressure is quite gentle, about Beyerdynamic level. Even the strap is not oppressive. Music penetrates only minimal outward into the environment through. The foreclosure of the outside world, however, is very good. You get at medium volume virtually no acoustic stimuli in its environment. The volume of a portable music player (such as Galaxy S3) is perfectly adequate and very satisfactory to my mind.

The processing is really fair and succeeded. Here massive plastics and steel were used for the headband and soft leatherette earpads and headband cushions. The cable has almost an ideal length to use the handset mobile, which he clearly is conspicuously large and you act with him more like a cyborg from the 80s.

The only drawback: The sickening stench!

Pro:
+ Transparent sound with punchy draft
+ Comfort
+ Good efficiency for mobile players
+ Effective Soundproofing

Cons:
Cable permanently installed
-Starker Chemical material smell, even after days
-Schlechter Support

* Addendum: The AKG support answered about a month after my request and would it actually can remain. I should like to address the dealer for this odor problem. That was all! This is the thing well for AKG off the table. I wish I could therefore deduct even one star, for this really bad service .... and I'm probably :-)