Summary: I have been using the K66 model for about six months now for various sound production purposes. They are semi-open, as some reviewers have already pointed out, so they are really best suited for home studio setups. These are not really meant to be used to plug into your mp3 player on the train. It is not a design fault that other people can hear what you are listening to - it's how they are made. Hence - 'open backed'.
Now that is out of the way...
Summary: I bought a set of these after reading many dubious reviews of all sorts of headphones in this price range. First of all, they are very light and comfortable, and you can wear them for hours with no problems. Secondly, they sound good to me: they have a nice full sound that is a lot better than anything I have listened to in a long time. Thirdly, they seem well constructed for the price.
For the price of these things, they are really good in my opinion.
Summary: The AKG K66 headphones are probably the best open-backed headphones you can get for such a low price. They are open-backed, so don't plan on using them to listen to Iron Maiden at full volume in some public place and expect to get away with it. Very comfortable and fairly durable, these headphones are good investment if you don't have the cash to get those ridiculously high-priced Bose headphones you've been dreaming about.
Summary: They don't swivel, so they can be incredibly uncomfortable. Everyone else can hear perfectly what you are listening too (that's bad.) They are pretty distorted, and the bass is about as powerful as a metronome.
Excerpt: The price indicates that it is not an animal! it looks like he flate to death in the media, but I think it may be useful as listening to so and so when mixing. and as one of his little brother if you put it to record a voice, he fled and shot many takes the microphone that would be good if it stays in the headphone! but hey it should not be done for recording ... but for the price ...
Summary: Lange Zeit war ich auf der Suche nach einem geeigneten Kopfhörer für meinen Mp3-Player, der alle musikalische Spektren (Rock, House, Dance, Jazz, Klassik, Hörbuch etc.) gleichermaßen abdeckt. Der AKG K66 scheint nun diese eierlegende Wollmilchsau zu sein. Im direkten Hörvergleich mit Sennheiser HD437; Sennheiser HD202; Sennheiser PX100; AKG K530; Beyerdynamic DT231 geht der AKG K66 klar als Sieger hervor.
Summary: Hallo, besitze die k66 seit einigen Monaten. Anfangs etwas skeptisch, dachte ich muss wieder zurückgeben oder wieder so ein "china"produkt, denkste! Bin mit der Zeit voll überzeugt was den Klang angeht. Bei Klassik Musik lassen sich sehr gut die Instrumente erkennen, was eigentlich für diese Preisklasse nicht selbstverständlich ist.