Most wireless headphones use Bluetooth as their streaming tech of choice, but the Sennheiser RS 220 use a 2.4GHz digital system instead. Sound is transmitted uncompressed to the headset and the range is fantastic - Sennheiser claims it's up to 100m, and while that's cut down hugely inside, it's enough for any house we're ever likely to own.
The signal is transmitted over the same bandwidth as Wi-Fi, but we found only very occasional interference occurred, and then only for a fraction of a second. Wireless performance in these headphones is excellent.
Long range is made all the more useful by the on-can controls of the RS 220. A trio of plastic silvery buttons sit on the underside of each ear cup, which is where your thumb naturally rests when you bring your arm up to your ear. The right buttons control volume and balance, the left input and power on/off. They are very quick to respond too - although the action of them could be a little crisper.
Using a proprietary wireless system, the Sennheiser RS 220 are deliciously simple to setup and get started. There's a pairing button on the back of the dock, and holding down the power button of the headset puts it into pairing mode too. Once paired, you only need to make sure both the dock and headset are switched on to get streaming working.
The sonic personality of the Sennheiser RS 220 is comparable to the middle players in the HD range - like the Sennheiser HD 650 and HD 600. Their open design provides a very open, wide sound signature that makes music and movies sound expansive and lush. Although the sound doesn't have the analytic clarity of something like the AKG Q701, top-end detail is good - and has the pleasant smoothness of the HD 598. The Sennheiser RS 220 sound is warm and relaxing, and adept at relaying the subtleties of lighter music.
Bass is generous, silky smooth and fairly tight, letting them cope well with the demands of beat-based electronic music. However, they can't quite muster the attack and power of closed back alternatives - like the Sennheiser HD 25 - or less laid-back open headphones. This becomes most evident in rock music.
Plenty of accessories are included, including international adapters
Given Queens of the Stone Age's Songs for the Deaf, the wide and warm style starts to work against these headphones, stopping them from creating that level of excitement the album's capable of. It's a return of the boxy mid-range we noticed in the RS 170 - and it's a Sennheiser trademark. That said, they make Homme's sound fantastic, and show up the times the music plays with the stereo make-up like few others. And just as the sound doesn't encourage excitement in aggressive music, that warmth can help give explosions in movies all the more impact.
If you prefer a sound that's lush and expansive rather than forward and aggressive, you'll find the Sennheiser RS 220 very easy to get on with. Their use of wireless is excellent, with a versatile dock and impressive range. With so few high-end wireless headphones available in the UK, they're simply one of the best wireless pairs money can buy right now.
A great implementation of uncompressed wireless music streaming makes the Sennheiser RS 220 the best wireless headphones we've tried in a long time. The relative wealth of selectable inputs and outputs mean they'll fit perfectly into most people's setups too. Sound is wide and open, though a little too warm and laid-back for some tastes. But overall they are another win for Sennheiser.