The Sennheiser RS 170 is by far the best wireless headphones I had been on my ears. Actually ordered as TV headphones for my now 82-year-old mother, where he proved once great, but also for my fidelity music demands far better than expected. Even in quiet passages absolutely no disturbing noise (digital wireless transmission), brilliant sound and best connection quality throughout the house, garden and on ...! The only slight suggestion of Sennheiser (because if one really wants to improve what) would be here even a small radio or infrared remote control to be accompanied by individual high / low volume or bass & surround scheme, because the push-button control on the right earpiece works only with a lot of sensitivity in the 'flying blind', which is probably in most cases means taking off the headphones for sound control - annoying eg while watching television when times must be quickly settled quietly at about loud commercials and then turning back to ask louder as the film goes on. Therefore 4 star (5 stars for the sound).
