The Sennheiser RS 180 wireless headphones deliver high-quality sound that's sure to please even the most demanding audiophiles. And the RS 180 comes with a multi-purpose transmitter\/docking station that charges the headphones.\n\tThe docking station, which is relatively bulky, has a standard 3.5mm input and a dual RCA output on the back panel that can be used to feed the input to another device. The headphones can be charged via an AC adapter. The RS 180 is surprisingly light for a pair of wireless headphones\u2013lighter, in fact, than some wired headphones I own. The headphones are "noise-cancelling" so some surrounding sounds can be heard and some music "leaks" out when played at high volumes. But the RS 180 also allows for a more immersive experience than most noise-cancelling headphones.\n\tThe earpads are made of velour. I would have preferred a material that traps less heat, since I live in Singapore, which is often hot and humid. Nevertheless, the earpads feel very comfortable, and they can be replaced by twisting them off. Removing the earpads also reveals the user-replaceable, rechargeable AA batteries\u2013one battery per side. Volume controls and balance and power buttons are located on the left headphone.\n\tThe RS 180 is powered by KLEER\u2019s lossless digital wireless audio transmission technology, which offers comparable audio to wired headphones. KLEER technology works at 2.4GHz, and Sennheiser says it will not interfere with other 2.4GHz devices. I did not explicitly test this claim, but I also didn't notice any obvious problems with my Wi-Fi network when using the headphones.\n\tSennheiser RS 180 Headphones: My Experience\n\tI connected the line input of the docking station to an Apple AirPort Express using a wired Ethernet cable. This allowed me to stream music from my iOS devices and iTunes running on a PC, as well as watch movies on my iPad, with music playback streamed via AirPlay to the RS 180, without ever leaving my couch.\n\tThe RS 180 music playback is excellent, and the headphones are great for listening to a variety of musical genres. I'm particualy impressed with the performance while watching movies.\n\tWireless range is good, though not exceptional. The RS 180 worked great in my mid-sized apartment with two walls between the headphones and the receiver. However, if I moved further away the signal broke up and playback eventually cut off.\n\tSennheiser RS 180 Headphones: Minor Gripes\n\tUnfortunately, I couldn't find any simple way to determine if the RS 180 battery was low, though the headphones start to experience dropouts when the charge drops below a certain threshold. And the device will eventually power itself off. The default NiHM batteries also lose their charge relatively quickly if the headphones are not left to charge on the docking station.\u00a0 To mitigate this issue, I used a couple of Eneloop rechargeable batteries, which hold a charge for far longer.\n\tIt's also next to impossible to adjust the volume controls without taking the earphones off, and it's very easy to mistakenly hit the power button when trying to adjust the volume. Finally, the docking station switches itself off after a certain amount of time. I wish it was possible to power it on using the RS 180 instead of having to walk to the docking station ever time you want to power it up.\n\tThe Sennheiser RS 180 headphones are pricey at $329.95. But the superior build quality means the RS 180 will likely last for years, and the ability to replace the rechargeable batteries and earpads is unique in today\u2019s culture of mostly throwaway design.\n\tBack view of the docking station and wireless transmitter unit.\n\tThe various controls are located on the left headphone.\n\tThe AAA rechargeable batteries are replaceable\n\tNotice the contacts for charging the batteries.\n\tThe detachable velour\u00a0earpads have a hard plastic back for clilpping onto the headphone.