I recently had the opportunity to spend 42 minutes with a Stax SR-X9000 and SRM-T8000 brought to the Toronto Audiofest by Headfoneshop.
Indeed beautiful and huge in person. I believe the outer diameter is comparable to the Susvara and Shangri-La Jr., likewise the Audio-Technica ATH-ADX5000 which I shortly heard at the show and can only describe as having sounded properly neutral and hence agreeable as suggested by its measured frequency response.
Pleasingly large earpad apertures for someone coming from the HiFiMan Arya Stealth and Meze Elite Tungsten. For context, my documented audio journey starts in
https://www.head-fi.org/threads/mez...eadphone-official-thread.959445/post-17509345 (post #4,541) and the chain of posts its links to,
post #4,665 of that thread covering my approach to EQ, then
post #5,152 showing my latest EQ results as aided by in-ear microphones (includes comparison to the Sennheiser HE-1), my finally combining my outdoor in-ear microphone HRTF measurements with the Reaper DAW and SPARTA's Binauraliser NF, AmbiRoomSim, and AmbiBIN plug-ins, the latter two finally presenting a nigh convincing head-tracked imaging of an orchestra positioned 14 meters away.
Given this, my main reason for interest in the X9000 other than its looks was the desire for an ultra-low distortion (confirmed by ASR's measurements of the 009S) electrostatic headphone with exquisitely sharp and clean transients (which I've found is one thing you can't really EQ), and a frequency response (which you can find in
post #1,346 of this thread) that is easy to EQ to diffuse field. Per
post #1,346, it indeed looks quite neutral, perhaps with a boosted midrange, then impressively no major treble nulls until around 1.6 kHz which could be beneficial for allowing binaural head-tracking to EQ in the natural treble nulls that move depending on the direction of the sound source.
If someone could listen to a treble and top octave sine sweep through their X9000 and confirm whether they can hear any sharp/deep dips between 6 kHz and 15 kHz, that would be great. Otherwise, the shallow high-Q jaggedness of that treble gives me some concerns regarding the driver quality or its control of resonances. Otherwise, the hype did have me working on first saving up for a Mjolnir Audio Carbon CC as a high-power, low-distortion, solid-state driver, after my seeing measurements showing that the Topping EHA5 doesn't cut it.
Comfort:
Finally, unto my subjective impressions, the first thing is that despite my hopes of pleasant earpad spaciousness,
the comfort just somehow didn't cut it for me. I was apparently the first person there to complain about a concentration of pressure on the upper and lower parts of the pads, there not being enough pressure around my temples and at the back of the pads. Positioning the pads higher didn't help much and approached the unacceptable case of my lower ear lobes being touched. The HiFiMan Serenity pads on the other hand fit my head perfectly, the Meze Elite despite its flat profile still being very comfortable and managing a full seal with great sub-bass extension, its main flaw being the pads' flexibility having the cups moving around a lot more (else the weight and smaller contact area moving the skin around my ears more) when I rotate my head toward the extremes.
I was
really hoping the X9000 pads would fit snugly and be more stable for use in endgame binaural head-tracking, but with this inability to get a good seal, it feels like a deal-breaker. I don't know if third-party pads are or will ever be offered (so long as the bass extension is good, I'm going to EQ it anyways). Maybe I could do a mod that inserts a spacer to shape the pads to better conform at the front and back. At least there was no driver crinkle. I had inside the Headfoneshop shortly tried the Audeze CRBN which was unfortunately driven by the Stax SRM-D10 which could barely get it loud enough (I likewise couldn't properly assess the sharpness of single-sample transients), this being surprisingly the first time I had heard a quite noticeably reduced soundstage or shrunken imaging; the pads though soft were too claustrophobic or unwieldy for me, my finding that pad size and feel can have subjective effects on image size; the driver crinkle was also horrid. I did shortly during the audio show just try on the 009S whose pads were quite more comfortable, having just a bit of driver crinkle, but its measured frequency response doesn't meet my standards. Otherwise, this and my relative satisfaction with the Meze Elite Tungsten may be the deal-breaker saving me $20k CAD.
Sound:
Expectedly from the frequency response, it simply sounded "agreeable" as I had found all other headphones at the audio show that were some form of neutral with sufficient ear gain. There were some points of noise or conversation nearby, but I'd say it wasn't too noisy or busy during my session. At best, the tonal presentation sounded comparable to my final Meze Elite EQ shown in
post #4,665, dynamics and bigness (e.g. with
Boulez' recording of Mahler 5) likewise being comparable. My Meze Elite EQ was already having excellent recordings like
Gardiner's Beethoven 4 sound exquisitely rich and detailed, whereby at best, the stock X9000 sounded similar. Transients in Rodrigo y Gabriela's "Oblivion" sounded clean and sharp. Track after track, it simply sounded "good" or "comparable", my already having a quite excellent sound at home, though I know that in isolation, the main limitation of the Meze Elite is that single-sample transients like in
http://pcfarina.eng.unipr.it/Acustica-samples/Dirac.wav don't sound as freakishly sharp and incisive as through the HiFiMan Arya Stealth with its sub-micron diaphragm (though you have to crank them up pretty loud for these differences to be noticeable, the T8000 having not been able to get this transient loud enough for me to tell whether the X9000's single-sample transients did sound sharper or comparably sharp; the same went for the Sennheiser HE-1). Yosi Horikawa simply sounded good, nothing special. Likewise, the panning of the distant sound sources in
didn't blow my mind like the Meze Elite did when I first auditioned it (that effect wore off on all subsequent listens). Regardless, there was always the constant nagging of this discomfort with the pads.
Conclusion:
So it's a bummer that comfort has seemed like the big deal-breaker in my selecting the X9000 as an end-game EQing and binaural head-tracking platform, but at least that may save me a lot of money to spend on other hobbies. Meanwhile, the HE1000se which I did try at the audio show with third-party sheepskin memory foam pads was exquisitely comfortable, its simply sounding "good" by my standards, its otherwise having no magical properties for classical music at least when driven with a Chord Mojo 2 isolated with fancy AudioWise RF Stop gear.
If the HE1000se or whatever HiFiMan comes up with next manages to have competitive distortion performance to the Meze Elite, then it may be worth it for the faster transients.
