The beginning of my electrostatic journey began here. I thought I’d heard it all, up until now that is.

Disclaimer:
STAX have not paid me to write this review.
Although The Audiophile Cafe is sponsored by STAX, the views and thoughts in this publication are my own unbiased opinion.
STAX, Audrey & Kay have been most gracious, kind and patient with me and I would like to personally thank them all!

The STAX SR-009 currently retails at $3,699 at the time of this article.

You can find the SR-009 here:
https://staxaudio.com/earspeaker/sr-009

Review equipment:
STAX SR-009.
STAX SRE-925S. ( Extension Cable. )
STAX SRM-700S. ( Solid State. )
STAX SRM-252S. ( Solid State. )
STAX SRM-700T. ( Tube. )
Burson Audio Conductor 3X Performance DAC & Pre.
Musician Audio Pegasus DAC.
IsoAcoustic Indigo isolation feet.
KECES Audio ePhono and ePhono Power.
Technics SL1200 MKII.
Ortofon Quintet Red.
Isonoe Isolation Feet.
Pro-Ject Debut Carbon Evo.
Ortofon 2M Red.
MacBook Pro.
iPad Pro.
Qobuz Studio Premier on both digital sources.
AFAudio & Custom Cans interconnects.
AFAudio & Audioquest NRG mains cables.
Audiowalle TP1000 mains conditioners.

Music:
Vinyl:
Jean Michel Jarre – Les Chants Magnetiques. ( Magnetic Fields )
Jean Michel Jarre – Revolutions.
Jean Michel Jarre – Equinox. ( 180 gram )
Jean Michel Jarre – The Concerts In China.
Depeche Mode – Violator. ( 180 gram )
Pink Floyd – The Wall. ( 180 gram )
Tears For Fears – Songs From The Big Chair.
Gustav Mahler – Symphony No.5.
Qobuz/Streaming:
Mikaela Davis – Delivery. ( HI-RES / 48.0 kHz )
Lissie – Thank You To The Flowers. ( Redbook 16bit / 44.1kHz )
Chris Rea – ERA 1. ( HI-RES / 96.0 kHz )
Fleetwood Mac – Audiophile Collection. ( Redbook 16bit / 44.1kHz )
Mastodon – Once More Around The Sun. ( Redbook 16bit / 44.1kHz )
Kylesa – Static Tensions ( Redbook 16bit / 44.1kHz )
The Audiophile Cafe Demo playlist:
https://open.qobuz.com/playlist/3785941 ( mixed file formats )

Please note that I have listened to other playlists since compiling this list in my initial article, so you will see me mention other artists and genres not listed above.

The Audiophile Cafe readers can receive 1 month’s free subscription to Studio, which allows you to listen to Qobuz’s entire music library in Hi-Res and CD quality. 
Please note: Existing Studio subscribers need to unsubscribe first before activating the gift. 
Please click on the following link for more:
https://try.qobuz.com/tqs_fr/?qbzs=society&qbzc=THE_AUDIOPHILE_CAFE&utm_source=society&utm_medium=partner_page&utm_campaign=THE_AUDIOPHILE_CAFE

What’s in the box:
Wood engraved presentation box with foam cushioning.
STAX SR-009 Electrostatic ear speakers.
Documentation.

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Spec:
Type: Push-Pull Open Back Circular Electrostatic Headphone.
Frequency Response: 5 – 42,000Hz.
Electrostatic Capacitance: 110pF (including cable).
Impedance: 145k Ω (including cable, at 10kHz).
Sound Pressure Sensitivity: 101dB / 100V r.m.s. 1 kHz.
Maximum Sound Pressure: 118dB / 400Hz.
Bias Voltage: 580V DC.
Left & Right Identification: “L” and “R” indicated on the arc assembly (inside head spring) Left channel cable is marked with a solid Line. Right channel is marked with a dotted Line.
Ear Pads: Genuine Lamb Leather (direct skin contact), high-quality synthetic leather (surrounding portion).
Cable: Silver-coated 6N (99.9999%) OFC parallel 6-strand, low-capacity special wide cable, 2.5m full length.
Weight: 1lb without cable / 1.3lb with cable.

Build & finish:
Within the large, well finished box we are greeted with an exquisit set of ear speakers enveloped in a perfectly cut and fitted dense foam protective layer. The cable neatly wound and kept in place by a cable tie.
The craftsmanship is elegant and classy. These ear speakers make a statement in design.
You can immediately sense the countless hours that have been spent to get the aesthetic & quality just right with a flawless finish and feel.
The cups have a beautiful mix of polished concave surround, bordered with a satin feel housing. The grills are a fine black metal mesh that feels sturdy, looks fabulous and contrasts well against the silver metal cups.
The headband is one little concern. Where the headband attaches to the adjustable sliders the connection feels delicate and I find myself being very mindful of this and always taking extra care when putting the SR-009 on my head.
STAX have made a cable that is very unique compared to anything else I have owned or reviewed. A flat ribbon style cable, It is robust in its build and doesn’t tangle. it and the extension cable both have a gold line running along one side of the cable making it difficult to plug it in the wrong way around. Saying that the 5 pin connector only connects one way. The plugs are solid and plug in firmly. I found no audible microphonics. The cable is far fatter and sturdy than the images suggest.

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Comfort:
I’ve owned and reviewed a lot of headphones from budget to high end. DJ, Studio and Audiophile alike.
The SR-009 are by far the most comfortable pair of over ears I’ve had the pleasure of wearing.
The ear pads are sumptuous and feel luxurious over my ears. They are soft and cushiony, yet they feel robust in their construction.
I experienced no heat or sweatiness, which is an issue I have had with many headphones.
My ears don’t come into contact with the “staters” as the ear pads are deep.
There is some weight to the SR-009, however it doesn’t translate directly to the wearing experience. STAX have designed these to sit comfortably on the head in a way that distributes the weight so it isn’t noticeable. I also notice almost no clamping force. In my experience I believe the weight of the SR-009 achieves a similar effect when worn. The headband is soft and forms to the top of my head perfectly.
Little positioning is required to get the required or correct sound.
I found I could wear these for long hours of listening time with no discomfort or fatigue.

Sound:
When I was first sent the SR-009 I had zero experience with electrostatic gear and at the time only had the SRM-700S driver to drive them with.
You’ll notice a lot of the above is a copy and paste from my previous article on the 700S & 009 together, however
I think it’s important to keep this review based on previous experience and honest. So it’s good to get some reflection on my initial thoughts.
Since the time of that article I’ve had the pleasure to spend a decent amount of time with the SRM-252S, SRM-700T and the SR-L300 along with a couple of very good DACs from Burson Audio and Musician Audio to bring out the very best in every electrostatic product I listened to. STAX have been more than generous in allowing me an extended period with each piece of gear. Allowing me to get a good feel for all of it.
Along with this I have been able to briefly borrow and demo a few electrostats privately so I was able to make some initial comparisons.
I now feel I am in a better position to write an actual review of these ear speakers.

Before I reviewed any of the above I spent a bit of quality time with my various planar magnetic headphones that I own in order to partially prepare me for the electrostatic experience.
Although there is a slight similarity, it really didn’t prepare me for what was to come.
I will never compare planars to electrostats again!

Straight off the bat, the soundstage is impressively spacious, with a lot of depth and heeps of headroom.
Next we have the best separation and imaging I have experienced to date, with instruments easily identified and positioned, even in noisier pieces of music. The imaging is amazing, with my eyes closed, this is the closest I’ve got to feeling like I was listening to a high end pair of speakers which were perfectly positioned. If it were not for being able to sense the SR-009 on my head, this would have been very close.

The signal from the various drivers to the 009s is silent. Even with each driver turned all the way up ( no music playing ) there was no audible noise or interference.

Toneality:
Bass was interesting. Although they don’t really deliver in the sub bass department, it is there in the background, textured, controlled and just enough to add to the overall sound.
Mid bass: “I hear a full bodied, articulate low end that performs with immediacy and a hard hitting punch.”
These were my words in my initial article on the 009s and the 700S and I’ve not changed my mind.
I may as well insert my thoughts on the mids & highs while I’m at it as my view hasn’t changed here either: “Mids are smooth and airy, capturing and reproducing vocals in a manner that puts the vocalist in the room with me. Highs are fast, detailed and shimmering with a depth that I’m not used to in the higher frequencies.”, however I’ll now add that acoustics, whether they be in the form of classical music, flamenco, unplugged performances from the likes of Eric Clapton, Nirvana and David Gilmour through to Metallica & Mastodon, or folk music like Clannad or Enya are an utter pleasure to listen to with an airy, organic toneality. Electronic music comes alive and the 009s are no slouch when it comes to delivering fast paced, complex and highly detailed tracks with authority and accuracy.
Where other headphones have more often than not, struggled with rock or metal, the 009s have no problems delivering a full bodied and agile performance. I will note here, that they are an unforgiving pair of ear speakers so they will reveal bad recordings in any genre, which I find is more of a “thing” in these particular genres. However if you present the 009s with a good to excellent recording, they are one of the better pair of “headphones” I have listened to rock and metal with. In fact they are one of my preferred pairs to listen to any heavy rock or metal albums on.

Live performances have often been hit or miss on my various headphones in the past.
The SR-009 is leagues above them all and brings any live performance alive in a way I find difficult to convey in words….
They’re astonishing, breath taking even.

Final thoughts & recommendation:
I won’t say they’re the best electrostatic ear speaker.
Because I haven’t heard every electrostatic ear speaker yet.
Yet I will say with my hand on my heart, they are the best ear speaker that I have heard yet.
Against every headphone or electrostat that I’ve heard, they annihilate every single one, in every aspect, across every genre.

Are they worth the high asking price?
I am a person who despite the gear you see in my reviews, is on a tight budget.
So $3,699 is a lot of money and a steep price tag for me.
However, I have to come at this in an unbiased manner and view this from the point of view of my readers, all of whom will be on different budgets.
When I take into consideration the other electrostats I’ve listened to in recent months, including STAXs own, more affordable SR-L300, I will say that I believe they are indeed worth their price tag.
I’m not saying this because STAX sponsor me, In fact they themselves would rather I write honestly about my thoughts here.
No, since I began this career in the hifi industry, reviewing gear from $30 right up to nearly $8,000 I’ve come to appreciate the craftsmanship, level of design and sheer time that goes into a lot of this gear…
They’re a worthwhile investment and if I had the budget to allow it, I would buy these ear speakers in a heartbeat!

I truly am sad to see them go! I hope the next reviewer enjoys them as much as I have.

Thank you to all of my readers, who make this endeavour meaningful and worthwhile.
Please remember to like, follow and share!

Sponsor:
Thank you to our partner Qobuz for supplying our account and endless high end music files.
You guys rock!