I searched but have a good wireless headset ...

Except for the usual sources with sufficient output voltage - listen for loud - should also contact the headset Chorübungen to my headphone output slightly weak Olympus LS5 recorder (which I otherwise can only recommend) are used.

After several hours of research on the internet following candidates came to me as a possible candidate in question:

- Philips SHD8600
- Sennheiser RS ​​180
- Sennheiser RS ​​170
- AKG K 840

My criteria were:
1. Sound
2. Sensitivity (-> volume to silent sources)
3. comfort
4. Range
5. Processing

As everyone knows who has ever engaged in pit or headphone purchase, it is very important to have a comparison device as a sound reference available, because you can hear the strengths and weaknesses of each device is best in a direct comparison. These served my best DT 990, which I very much appreciate very much as before!
This is important to note in my review of the chapter "sound" - someone with other listening habits is perhaps (except for objective criteria such as clinking and clanking) reach different conclusions ...

First, I ordered only the Philips SHD8600 because I had identified him as the winner "with a very good sound" and it was the cheapest in the selection (what is one you go wrong).

Result:
1. Sound
Intrusive, hardly middle, highly exaggerated bass and treble.
With greater volume very quickly strong distortions: Bass only booming and rattling - the membrane apparently the stop.

2. Sensitivity
Weak. In addition, in quiet passages repeatedly misfiring!

3. comfort
Default: I wear glasses: the ear cushions creaked at the temples.

4. Range
Not tested further.

5. Processing
Ok.

Point 1 (sound) was the KO criterion, which is why I have the Philips SHD8600 returned immediately.

In the remaining three candidates, I then the Sennheiser RS ​​170 does not even moved on because the described in other reviews sounds with glasses into consideration and instead both the Sennheiser RS ​​180, as well as the AKG K 840 ordered.

First, I have been testing the RS 180:

1. Sound
Compared with my DT 990 more highs and more bass - for example, as if there is something "Loudness".
The bass is nice and dry and clean.
Even at higher volumes no distortion and no rattling or clanking.
After hours probehören really enjoyable. Good space and a clear, airy sound. Not so neutral as the DT 990, but for me acceptable.

2. Sensitivity
All sensitive enough, especially when the "ALC" automatic volume control activated.

3. comfort
The listener is secure very good and firm, but just not yet. So you can move well clear, without the need to have concern that he might fall down.
But he does not sit firmly, so wears comfortably even after hours.
In particular, the soft velor material contributes to this, that even with me as eyeglass wearers no noises and that it fits properly in spite of the temple.

4. Range
Definitely not 100 m, as advertised, but for my purposes sufficient even in adjacent rooms completely interference-free reception - even on the move!

5. Processing
Earcups very pleasant with its beautiful suede, all the rest in plastic that is now ok, but not super valent (such as when called later AKG). Overall, for me even at the price ok - in the hope that the material also remains and unscratched quickly or ausleiert.

After that the AKG K 840 came to the series:

Here initially having to unpack most joy made: only the packaging is a real treasure (jewelry) box.
Then the protective case comes with all the really high-quality acting accessory cables and parts to days. This really makes you want more.
Even the headphones are really processed best by far. Of the whole look and feel of a clear ++ until here.

1. Sound
Bass and particularly very present midrange, treble: yes, where are they?
I liked it at first did not admit it and have been testing various pieces of music and each compared with my DT 990 and the Sennheiser RS ​​180.
Both of these triggered each very nice the room and recorded, each in his characteristic, a very nice sound.
The AKG K 840 acts in direct comparison just flat and dull.
Very unfortunate.

2. Sensitivity
Loud enough he is all.

3. comfort
Since the AKG K 840 is not the earcups encloses special due to the smaller "ear pieces" just resting, he is less tight and secure as the Sennheiser RS ​​180, but safe enough and definitely, also because of its low weight very comfortable.

4. Range
So of reach in the true sense of the word one can not speak, unfortunately. The AKG K 840 works in principle only in the same room by there is also the station, outside is immediately closing.
But what a lot of serious weighs, is the fact that I often found himself at a distance of less than two meters audio dropouts - and that should not happen now. Maybe it's my wireless AP, which was located in the immediate vicinity, but the Sennheiser could be impressed by it at all.

My personal favorite would have been, despite the by far the highest price of the AKG K 840. Haptics, perceived value, the complete accessories, the opportunities that arise through the small, battery-powered transmitter, ... all very good arguments that the AKG K 840 tasty gave me.
Unfortunately (I must say) are for me the 1st player to skip in the immediate vicinity and 2. the disappointing sound absolute knockout criteria, which is why I returned the AKG K 840 heavy heart again.

As I explained input, the sound was the single most important criterion for me.
There has been given in the form of the Sennheiser RS ​​180 a clear winner for me - although my old DT 990 still like better.
The Sennheiser makes but by its "Kabellosigkeit" simply fun and also still sounds good. I will definitely keep.
One point deduction, because I now but the freedom of movement with cordless transmitter like the AKG and its very good haptics / perceived value a little miss ...