When I compare the soundstage performance to the RS180 to the HD650 driven from the Grace m902 amp (The m902 has one of the widest soundstage performance among many amps that I have tried), the RS180 soundstage feels quite noticeably narrower. However, it makes up the loss in width in the depth and overall soundstage performance that is better than the HD650’s. While the HD650’s soundstage sounds fairly flat and two dimensional, the RS180 has a real depth in the sound and a fairly coherent spherical soundstage. Not bad, considering the RS180 does its own digital to analog and amplifier job within the enclosure of the headphone.
The RS180 wears very comfortably, with the D-shaped housing that mimics the HD800’s frame. The pads are made from very high quality verlour, and the RS180 is more comfortable than the HD558/HD598/HD650 wired models, both due to the better verlour material as well as a softer headband clamping force. I also noticed interesting differences between the RS180 to the conventional wired models. The headband portion of the RS180 is noticeably longer, and somehow that long headband design makes it easier for the RS180 to maintain a comfortable yet firm grip on the head. Also, while the D-shaped housing mimics that of the HD800 (though in smaller diameter), the RS180’s orientation is totally the opposite to that of the HD800.
What about the wireless performance? If you’ve bought a wireless router before, then you’ll know that the claimed wireless range is almost never the actual range. Likewise with the RS180’s claimed 100m range. It may be possible if you live in a totally open space with no walls or any sort of physical obstructions. The RS180, however, gives quite a nice range of wireless coverage, roughly 15 to 20 meters depending on the construction of the building. The good thing about the Kleer transmission is that audio quality doesn’t suffer as the distance is enlarged. Rather, you get dropouts on the signal if you get too far from the transmitter. The Kleer transmission is able to transmit pure uncompressed audio signal over the 2.4GHz digital link, and the signal is indeed very clean and CD-like. Although the fidelity cannot rival a high end set up such as the Zana – HD800 combo, but no one really expects the wireless RS180 to go that far either. The Kleer technology also allows up to 4 headphones to be used at the same time from one transmitter source, although I didn’t really had the headphones to test out this feature.
The RS180 headphone requires batteries for operational. One AAA battery per side. But unlike the Beats Studio headphones, the RS180 comes with a recharging mechanism through the transmitter that also works as a stand for the headphones. Very smart design, and I never find myself running out of juice with the RS180. The battery life is claimed to be 24 hours, with charging time to be around 8 hours. The transmitter requires an external 5V DC supply, and Sennheiser supplied a universal voltage wallwart with removable AC plugs (UK, US, EU, and AU). What I find to be objectionable is the fact that the transmitter comes with a 3.5mm jack input. Not the best for audio connection, especially because it’s hard to find a good RCA to mini jack cable off the shelves. The transmitter stand, however, comes with an RCA out. A design decision that is quite puzzling to me. But still, I’m using the cheap RCA to mini jack cable that Sennheiser supplied with the RS180 to connect the transmitter to the Grace m902’s DAC output for this review, and I don’t really have any major complaints of the audio performance. The RS180 headphone itself comes with a volume control and L&R balance control, in addition to the on/off switch. The transmitter stand comes with an on/off button, as well as an ALC button that is designed to help to enhance speech performance (audio books, perhaps?).
Wearing a wireless headphone is truly a remarkable experience. I set the transmitter station on my workdesk, and I’m free to go outside to sit on the porch with a book in my hand, enjoying the fresh outdoor air. Yes, you can do the same thing with a transportable set up, but you still have the clutter of portable DAPs and portable amps to carry around. The RS180 is a totally different experience. Without the constraints of wires, the RS180 truly brings out new ways for me to enjoy my music.
Gears used for review:
Headphones: Sennheiser HD650, HD558, RS180
Amplifiers: Grace m902 (for the HD650 and HD558)
Source: HRT Music Streamer II+ (to the analog input of the RS180 and the analog input of the Grace m902)