(Image credit: Future)

Stax has been in business since 1938, and has been in the business of electrostatic headphones (or ‘earspeakers’, as it has always insisted) since 1960.

Its acquisition by Chinese enormo-brand Edifier in 2011 doesn’t seem to have shifted its attitude or priorities in the slightest – which is why this SRS-X1000 ‘earspeaker’ system is getting the once-over.

Is the SRS-X1000 better than some boring old ‘headphones’ at the same sort of money? That's what this review is here to help you with.

Price & Availability

The Stax SRS-X1000 – which combines the SR-X1 and SRM-270S – is on sale now, and in the United Kingdom it’s priced at £1095. It’s a slightly less punishing $980 in the United States. While in Australia it goes for AU$1895.

Obviously the configuration of this system makes it rather unusual – but if it’s high-performing wired headphones at this sort of money you’re after, you’re not short of choice. Audeze, Focal, Grado and Meze Audio all spring to mind as having deeply impressive alternatives to tempt you with.

Features & What's New?

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The SR-X1 ‘earspeaker’ uses what its manufacturer describes as a ‘medium-sized’ (which translates to ‘30mm’) push/pull electrostatic circular sounding body with a high-precision fixed electrodes – two parallel fixed electrodes, in fact, sandwich a high-polymer film diaphragm suspended between them.

As regards the overall weight of these components, Stax simply isn’t saying. It will give an estimate of the frequency response this arrangement is capable of, though – 7Hz - 41kHz. Both numbers indicate the SR-X1 can operate well beyond the two extremes of human hearing.

As regards ‘features’, well, that’s about it. It does one thing, and it’s designed without apparent compromise to do it as effectively as possible.

(Image credit: Future)

The SRM-270S that’s supplying the electrical impetus to the SR-X1, meanwhile, is just as focused and purposeful. It uses a low-noise FET in the first-stage amplifier, and this is paired with a refined (or ‘white’) emitter follower circuit in the output stage.

Absolute clarity of sound is the intention, and certainly when it comes to measurements the SRM-270S seems ready to do the business – frequency response to 35kHz and measurable harmonic distortion of less than 0.01% are both very encouraging figures.

Performance

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This is a ‘system’, of course, so is a little more involved than regular headphones. Connect the SRM-270S to mains power using the supplied adapter, then connect a source of music to the stereo RCA inputs. Plug the SR-X1 into the front using the ‘Pro’ five-pin connection and dial in the appropriate amount of volume. Position the SR-X1 comfortably (a process that’s made just slightly tricky by the uncooperatively wide cable they connect to the SRM-270S with) and only now are you good to go.

It’s worth the relative amount of faffing about, though. The SR-X1, as driven by the SRM-270S, are an extremely enjoyable and very adaptable listen – it doesn’t seem to matter to these ‘earspeakers’ the sort of music you like to listen to. They can make numerous pertinent observations about it at the same time as serving it up in a thoroughly engaging and musical fashion.

At every stage, the Stax system is an entertaining and insightful listen. Detail levels are extremely high across the board, so not even the minutiae of harmonic variation can escape them.

Low frequencies are deep and textured, punch with solid determination, and are so carefully controlled at the onset of individual sounds that rhythm expression is confident and naturalistic.

The top of the frequency range is bright and shining, but there’s plenty of substance to counterbalance the brilliance – and, again, an attention to detail that means even the most transient event in a recording is given its appropriate weighting.

It’s the midrange, though, that’s the real star here. The Stax communicates a singer’s character and intentions with absolute positivity – they’re so direct and articulate when it comes to voices that you’re never in any doubt as to emotional state or motivation, let alone in the dark as to a vocalist’s technical proficiency.

(Image credit: Future)

The frequency range is integrated smoothly from top to bottom. The tonal balance is quite carefully neutral, so it falls to the recording you’re enjoying to inject any sense of heat or coolness.

The soundstage the Stax can generate is extremely wide, lavishly spacious and absolutely controlled – even in a dense or busy mix, each element of a recording can easily be individualised. There’s elbow-room for everyone, but this is not at the expense of integration or unity. Each and every recording is presented as a singularity rather than as an assembly of discrete occurrences.

And when it comes to dynamic impetus, the SRS-X1000 needs no excuses making for it – it tracks the shifts in volume or intensity during a recording with something approaching relish.

In fact, shortcomings are very few, have next-to-nothing to do with the sound the system makes, and are (in one case, at least) quite predictable and easy to live with.

This predictable one concerns the amount of sound that leaks backwards from the rear of the slatted earcups. All open-backed designs are leaky, of course – but the Stax is almost wilfully so. If you weren’t intending to use this system for solo listening then it won’t take long for anyone within earshot to suggest you do so.

What’s altogether more unexpected, though, is the effect touching the earcups can have. Put your hands on them to adjust their position (or for any reason) and you’ll provoke a disconcerting little squeak or two - and this happens whether or not you’re listening and, in fact, whether or not the SRM-270S is powered up or not (although it’s far more pronounced when the power is on). ‘Unusual’ is a polite way of describing it, as is ‘unexpected’.

Design & Usability

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For something racily called an ‘earspeaker’, the Stax SR-X1 looks an awful lot like a pair of headphones. A quite old-school pair of headphones, what’s more, one that’s light (234g without the cable) and rather plasticky.

There’s only some artificial leather comprising the wafer-thin headband and some genuine leather (so long, vegetarians, it was nice knowing you) covering the memory foam of the earpads as relief – otherwise, from the hard plastic that makes up the slatted outside of the earcups to the cover of the rudimentary ‘friction pole’ headband adjustment mechanism, it’s plastic all the way.

The SR-X1 use metal for the frame structure. It offers a rigid assembly, and the arc, yoke, headband adjustment mechanism and headband itself are all integrated. This method, according to Stax, offers superior resonance suppression. It also allows the weight to be kept to a minimum – this, along with some well-judged clamping force, means the SR-X1 are comfortable in situ. They’re certainly easy to wear for longer than it takes that sheepskin to heat your ears.

(Image credit: Future)

The SR-X1 are supplied with a 2.5m length of broad, flat low-capacity cable with six parallel cores. It splits at one end – each earcup must be wired and has a click-to-fit connection in order to make it happen. At the other end, the cable connects to the SRM-270S using a proprietary ‘Pro’ five-pin connection.

That’s on the left of the little (38 x 132 x 153mm, HxWxD) SRM-270S’s 3mm thick aluminium fascia. In the centre there’s a small LED confirming the unit is powered up, and on the right a small rotary dial that takes care of ‘power on’ and also functions as a gain control.

The aluminium case of the SRM-270S is basically all aluminium extrusion, which means the entire thing is a heat-sink. The rear of the box features unbalanced stereo RCA inputs and outputs (weirdly, they’re grouped together as ‘L’ and ‘R’ rather than ‘in’ and ‘out’) and a socket for connection to mains power.

Stax SRS-X1000 review: Verdict

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The reasons to consider the Stax SRS-X1000 are pretty compelling, thanks to some interesting technical highlights and profoundly competitive sonic performance.

But then the reasons to give them no consideration whatsoever are equally compelling, given this sort of money on ‘normal’ headphones would deliver far higher perceived value and well as being less, um, touchy about being touched.

Also consider

The Audio-Technica ATH-WP900 are not as expensive as the SRS-X1000 (although they’re still pretty pricey) and in their own way they’re just as much of a throwback. But if you like the looks you’ll fall even harder when you hear them in action.

Or you could go the whole hog, budget-wise, and throw in a bit of wireless connectivity too, by checking out the Focal Bathys MG – exquisite sound and perceived value that’s off the scale compared to the Stax system is just the start of it…