Sennheiser RS 185 Mobile homers

Wander your home free from the worry of trailing cables decapitating the cat. Sennheiser’s wireless ’phones are a real home helper.

Regular readers may remember us lavishing praise on the predecessors of the RS 185 — we have long been fans of Sennheiser’s wireless headphones for the home. These are not Bluetooth models designed to free you up on the daily commute; they are strictly for the home, and use a superior transmission method that doesn’t involve data compression during the process. And for once the words on the box speak true — the RS 185 do deliver genuine “hi-fi digital wireless uncompressed sound”.

The new range replaces a trio of models that were showered with awards following their release few years back — the RS 160, 170 and 180. The new range follows up with the RS 165, 175 and 185, plus an RS 195 model which was originally intended to be released only as a specialist model for audiologists (it enables specific corrections for hearing deficiences), although this model is now listed on Sennheiser’s website with the rest of the range.

There are a great many differences in these next-generation wireless models compared with the originals. This time all the models come with a headphone stand which has the inputs and transmitter built in (previously the entry-level RS 160 model had only a small separate puck unit for this purpose, which many may have found a little inconvenient). The transmitters can now also service two pairs of headphones each, making his and hers headsets an easier proposition where previously re-pairing would have been necessary.

But the most fundamental difference, perhaps, is a change in the wireless technology itself, moving from the third-party Kleer transmission to Sennheiser’s own proprietary wireless system. This promises reception up to 100 metres given line of sight — domestic inconveniences such as walls will reduce this, but as we’ll see, transmission appears just as strong as the Kleer previously used.

For this review we lived with the top of the main range, the RS 185. As with the former RS 180, this is the only open headphone in the group, as opposed to closed. Not so long ago nearly all home headphones were this way — open headshells allow a more airy open sound. But the trend these days is firmly closed, especially with headphones that double up for duties outside the home, where the spill of sound from open designs is just downright antisocial. The choice of open design at home will depend on whether you intend listening in the same room as others — we were barely through our first song before the missus, focused on some CSI murder, banished us from the sitting room couch and sent us up to the music room to spill our audio in peace.

Sennheiser RS 185 The control layout on the headphones themselves has evolved — still all on the right headshell, but no longer is the power button situated dangerously between the volume controls; it has been moved to the outer headshell, while on the RS 185s a circle of controls offers volume up and down at the bottom, left and right balance adjustments above that, and a ‘Level’ button between those. We are delighted by the ‘Level’ button, as it addresses our main (almost only) criticism of the first generation, which used automatic gain control to achieve the optimum transmission level between base and headset. While this made sense in some ways, it also caused the audio to ‘pump’ as it transitioned between quiet and loud passages; this was especially noticeable and undesirable with classical music. Now you have the choice — fix the level manually, or let the auto gain to do its thing. We couldn’t ask for more.  

Sennheiser RS 185 Set-up requires nothing much more than loading the supplied AAA battery into each headshell via an easily twisted earcushion removal, and then plugging in your cables to the transmitter base. No ‘pairing’ operation is required, since the headphones come pre-paired with the transmitter, and in the new generation the base is activated automatically when you power up the headphones, another timesaving bonus.

Connectivity is improved over the first generation as well. The RS 185 transmitter base has both analogue and optical inputs, with a switch between the two on the rear. The optical input is very useful for TV audio — all modern TVs offer an optical output at fixed level (indeed some no longer offer an analogue headphone or line output) and the wireless Sennheisers are ideal for cranking up those action movie soundtracks when everyone else is asleep.

Sennheiser RS 185 But for music use also, the optical input allows a direct digital input. Given that the transmission between base and headset is digital, we had previously commented that the analogue-only input of the previous generation meant that digital sources had first to be made analogue, then converted back to digital for transmission — not ideal. Now you can give the Sennheisers the PCM original and, while we’re not sure exactly what goes on prior to the wireless transmission stage, there’s a high probability that the first digital-to-analogue conversion will take place only at the final stage, in the headphones themselves.

The analogue input uses proper RCA phono sockets, and as mentioned gives the choice of automatic gain control or manual level control, limited first by an input gain control on the transmitter, ideally set as high as possible without audible distortion, after which the volume controls on the headset itself provide your local adjustment. Being finicky, we much preferred the manual method (a red light usefully indicates overload), but the automatic system worked well and is a handy fallback. Be a little careful switching from auto to manual via the headset — it could raise the level dramatically (though Sennheiser incorporates a friendly fade out and in as this happens). Switching between analogue and digital inputs can, of course, cause a sudden jump; Sennheiser correctly warns against this in the full manual (supplied on CD or online), and sensibly doesn’t allow this switch to be made from the headphones themselves.

We started our listening with TV-based optical input, and the RS 185s proved very impressive performers with soundtrack material — rich and powerful, crystal clear for dialogue, and notable for a slightly unusual quality, a wide spread of wraparound sound. The main delivery seemed to project from slightly behind our ears — it would still centre effectively, but the result was an almost wraparound quality from the back of our ears to a forehead centre position. We could see no obvious reason for this — with the earcushions removed, the diaphragms are precisely centred; it might possibly be an effect of the cushions themselves, which curve behind the ear but are straight at the front, relatively restricting audio entry from that direction. Results will likely vary according to your particular head. Though slightly distracting at first, this directionality does nothing to detract from longterm listening, nor from the wonderfully musical performance of the RS 185s — as with their predecessors, there is zero penalty in sound quality for your decision to go wireless compared with Sennheiser’s highly regarded wired headphones. Indeed if you find the company’s mainstream Urbanite and Momentum models slightly soft or emphasised in the bass, you will prefer the balance here — bass is solid but entirely without bloom, and treble vibrant and open; we so rarely spend time with open headphones these days that it was a reminder how much they free the ears from any sense of enclosure. On and on we listened with no hint of tiring our ears, nor was the ultimate level limit of Bluetooth designs apparent here — with the manual level set right on the red clipping light, there was plenty of headroom for special moments or ramping over time.

Range was exceptional too. We still have the previous generation RS 170 in residence, and range here was slightly improved. Don’t expect 100 metres in the real world, but certainly one or two rooms or floors distant is possible. As for battery life, Sennheiser claims 18 hours, but if you always store them on their stand, it’s highly unlikely you’ll ever drain them.

We never once needed the left-right balance adjustments; they might be useful for someone a little deaf in one ear but there’s really no need for these on the earpiece — they are more likely to be used in error than in earnest. The switch between auto and manual (usefully given a raised dot to make finger location easy) was much used, mainly for comparison to decide if there was the lightest of treble drops when switching to auto gain.

Speaking of which, for those preferring a closed-back design, we note that the RS 175 doesn’t include the manual/auto option, nor the left-right balance control (no great loss, this), instead offering bass boost and virtual surround modes. The RS 165s have no digital input and also significantly lower range, according to the spec sheets.

Sennheiser maintains its lead in wireless headphones with the marvellous RS 185. The open design limits their use to environments where you will be alone — they spill too much audio to use them in the same room as someone else (if you prefer closed, consider the RS 175 model instead). They combine comfort with excellent sound quality, while offering improved connectivity, range and operation over the previous generation. Unbridled recommendation. 

Sennheiser RS 185
Price: $599

+ Great headphones; No sonic penalty for going wireless; Control & inputs improved over previous generation
- Open design spills sound

Type: over-ear open-back wireless headphones with base station

Base station inputs: 1 x optical, 1 x RCA analogue

Quoted battery life: 18 hours

Weight: 310 g (incl. batteries)

Warranty: One year

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