Heya chief. very nice find! Not much review.
Here's one though - German thru Google Translate:
AreaDVD.deConclusion: AKG K 840 is connected to the KL one indeed quite expensive, but managed to sound convincing wireless headphones. Tonally neutral, very precise and with dry, powerful bass, he plays in test his talent could. The finish is good, the headphones are a quality image of what you would expect in this price too. For distances of up to 7 meters can enjoy crystal clear playback Mandie and without interference or interruption. In the test operation, we have 2 x 5 hours run listening sessions without having to recharge the battery must also not take for granted.
Tonal + neutral
+ Prima Detailing
+ Good space
+ Send Optics
- Quite expensive