I own the HDR170 Sennheisers which I use while doing yard work, reading outdoors. etc. They operate well out to about 150 feet from control. They also produce a simulated surround which might be usable for watching movies?? and bass boost. These features are switchable on/off. I use the unit plugged into a Squeezebox and have been pleased for the most part with the sonics. Battery charge life is excellent.