Stax SR-X9000

I couldn't find a thread, so I thought I'd create one, mods pls move if I've missed it.



Stax's new flagship. I've been listening for about 4 days so far. These are legit, but I'll report back with longer thoughts once I've done my full review.

Short impressions

Overall I'm very impressed. Based off of others impressions, I thought that in terms of overall character they might be a laid back warmer listen, but they aren't coming across as that, at all really. I don't really feel like they are an improved 007, or an improved 009(S.) They are doing their own thing. More treble than I was expecting, or maybe it's just a spike somewhere in the treble rather than an overall elevation of the highs. They are the "biggest" sounding stax I've heard but not as big as the Shangri-La Sr sounds. When I say "big" I mean in terms of the overall sound, not necessarily soundstage width etc. Its hard to explain, but to me there is a difference between soundstage, and how "big" the overall sonic picture is.

Soundstage width is wider than the SR007 and SR009. Imaging seems to be a very strong point for these. The space between instruments within the soundstage is very impressive, and there is real depth going on. Also they are most detailed stax I've heard, but they seem to lack the last 5% of micro detail and "delicate" sound the Shangri-La Sr have. I have not heard the original omega from Stax so can't comment there.

Also,

Positive - The bass. Honestly surprising. I'm running a modest low shelve from 100hz on down as I do with most headphones to some degree, and the bass is very satisfying. It takes the light low shelve like a champ, no distortion, or other problems. Could happily live with this bass and I'm not a fan of the 009's bass at all really. Even if you boost it there is just no slam or impact at all.

The negative? 3khz. There was something I couldn't put my finger on. It wasn't "brightness" in an overall sense from the treble. It was just anything above a medium volume level, especially with vocal stuff, was annoying the heck out of me and ultimately ruining the listening experience. Doing a 3.5db reduction at 3khz fixed it entirely and now they are very much in my favourite headphones group for their overall experience. I know some people will blame it on my cables, or my amp (though I'll hopefully have my new amp by august but I digress,) or DAC, or whatever. I've never experienced anything like that making enough of a difference at a specific frequency to fix something to that extent, but hey maybe they would be right.

Its 3khz peak isn't as bad as the CRBN, and when I say "bad" I mean for me personally. Some people love the CRBNs stock tuning, and it is even more forward than the X9000, so YMMV.

Build quality impresses, and the leather for the earpads is probably the nicest I've felt thus far.

 

Hi Guys,

Today we are talking about Stax Headphones new flagship model, the SR-X9000. For the rest of this review, I’ll just refer to it as the X9000.

The X9000 is the very long anticipated replacement for the SR009 and SR009S, the previous flagships from Stax. With such a long history and such a dedicated cult following, a new flagship from Stax is a big deal, at least in terms of the headphone hobby. I remember people speculating what would be next ,even back in 2014/2015, and now today, in 2022 we have the X9000. The X9000 was released back in September of 2021, but I think Stax has been a bit overwhelmed with orders, and is struggling to fulfill the demand from the community. Wait times as of right now are very long, and there are still people who ordered back in October/November 2021 (currently July 2022) waiting for their headphones to arrive. With that being said, there does seem to have been a few more shipments arriving lately, so if you are reading this and still waiting for your pair, I hope you will have them soon.

The X9000 builds upon the “omega” legacy, which started with the original SR-Omega, back in 1993. Then there was the SR007, the SR007mk2, the SR009, and the SR009S. I have not heard the original Omega from 1993, which does have a cult following of its own, but I have heard all the others. The X9000, to me, is not really an upgrade of any one particular Stax Flagship, nor is it a mix of SR007 and SR009. It is sort of doing its own thing. I have done a lot of comparative listening, and the X9000 is absolutely my favourite Stax headphone I have heard thus far, minus one caveat I will mention a bit later.


The bass of the X9000 has been surprising. Not so much in its overall level, though it does have more bass than the SR009. It has a bit less in terms of quantity than the SR007, with the Sr007 sounding fuller and warmer, with a bit more mid bass. The X9000 has the best quality of bass I have heard from Stax. It’s very fast, with more impact than is usually associated with something like the SR009. Admittedly, it does not have the impact or slam that the Abyss 1266TC has, but not much does to be honest. In terms of level, I could certainly enjoy the X9000 in its stock tuning, but did find a +3db low shelve brought it more in line with my personal preferences. I never found myself wanting more from the low end performance of the X9000, and its sub bass was also quite impressive for an electrostatic design.

With regards to the X9000’s midrange, Stax seems to have err’d on the side of slight warmth, and a forgiving nature in the low mids, much less so than the SR007, but more so than the SR009. Now, this brings me to the caveat I mentioned earlier. In the first couple days of listening with the X9000, there was something that just wasn’t sitting right with my ears, and was annoying me at anything above a medium listening level. It was the peak at 3khz. I just couldn’t get on with it, and ended up lowering it by 3.5db via EQ, and the X9000 went from being frustrating to listen to (because I could tell it was a very accomplished headphone) to being one of the best I have heard, period. Now, to make a quick comparison, the Audeze CRBN has an even bigger peak at 3khz, and I found I was not able to rectify them with EQ to be in line with my preferences. There are a lot of people out there who enjoy the stock tuning of Audeze’s CRBN, so you may hear the X9000 and be totally ok with its peak at 3khz. Perhaps I am just sensitive to this area, and you may not be.


The treble of the X9000 is not dark, nor is it bright. It seems to me to be leaning towards a relaxed presentation, neutral-ish, but leaning towards dark rather than bright. Given peoples issues with the somewhat bright treble of the SR009, this tuning decision makes sense. I wouldn’t say the X9000 itself is actually a very laid back headphone, its still relatively forward sounding, and it doesn’t strike me that it is masking detail by being overly dark. The treble and leading edges or notes are fairly incisive sounding and I never founding myself wincing at cymbals hits or shrill vocals when listening at spirited volumes.

Now, for me personally, what made the X9000 really standout was its technical performance. I have seen some impressions that felt it didn’t really improve over the SR009 in this area, and I have to be honest, I feel completely the opposite. I have listened extensively back to back with the SR009, and the X9000 really has taken a big step forward. Pretty much every single metric has been improved over the previous flagship. The sonic image is much bigger, and the soundstage is wider. The overall detail levels are again improved in comparison to the SR009. Imaging is also improved over the SR009, which is surprising as I always felt that was one of the SR009’s strong points. I have a suspicion the ear pad design of the X9000 may be contributing to the overall larger sonic picture, as well as the larger driver. Stax really does seem to have managed to improve the drivers performance compared to their previous flagship models, so in that sense, the ten year wait between the SR009 and X9000 was worth it.

In terms of build quality, the materials used, and overall feel, the X9000 is on par with the best I have come across. It is a lightweight and extremely comfortable headphone, and also feels more premium than the other Stax headphones. The leather of the ear pads feels very nice and “high quality.” This is one area I felt Stax could improve upon previously, and I have to admit that for the MSRP, the X9000 certainly feel as if they are made to that standard. In comparison, something like the Hifiman Shangri-La lacks in this area, but the X9000 has really delivered on its promises of being a high end flagship in terms of build quality. The X9000 also comes in a nicely done pawlonia wood box, and the overall package feels well put together, and again, of a “premium” nature.


One comparison that makes a lot of sense is to compare the X9000 to the Hifiman Shangri-La Sr. Both are flagship electrostatic models, though as I mentioned previously the build of the X9000 is certainly superior between the two. However, sonically speaking, its a much closer battle. The X9000 has a similar “large” sonic image to the Shangri-La, with the Shangri-La having a taller soundstage,but the width between the two being similar. The overall detail levels are very similar but I would give the edge to the Shangri-La by about 5’ish %. The Shangri-la is a slightly brighter, and also more forward sounding overall, with a sharper leading edge to notes. There is a sense of delicacy and air that the Shangri-La has that the X9000 doesn’t. With that being said, the X9000’s tonal balance works very well for some music, more so than the Shangri-La. If you are concerned with budget, the X9000 is the obvious choice ($6200MSRP vs $18,0000MSRP) because it comes incredibly close to the SR in over technical performance whilst also performing better with some forms of music.

In comparison to the Abyss 1266TC, these are actually two very complimentary headphones. The Abyss has this raw energy, slam, visceral quality that I have still yet to hear a headphone match. It is also a very detailed headphone with a highly capable technical performance, though I do think the X9000 may slightly beat it on the detail front, but the difference is incredibly small. I could honestly see someone deciding upon these two headphones as a pair of complementary flagships to own.


Overall? The Stax SR-X9000 has taken a long time to arrive, but I do believe it’s been worth the wait. It’s the most complete and competent Stax headphone I have personally heard (keeping in mind I have not heard the original omega.) Stax seems to have listened to customers complaints about their previous headphones and done their best to address them. The somewhat lean and bright sounding SR009 has been fixed, and the somewhat overly warm and lacklustre build quality of the SR007 has also been addressed. That’s not to say the SR-X9000 is without fault, as I do find it has too much energy in the 3khz range, which is thankfully easily fixed by a tiny tweak with EQ. Once that has been done, the SR-X9000 has comfortably made it into my top 3 personal favourite headphones. The Abyss 1266TC, The Hifiman Shangri-La SR, and the SR-X9000. I look forward to seeing what Stax comes up with for the next flagship, see you in a decade or so

 

Always love to see your reviews of less talked about gear. There's a fantastic amount of technical information in what is relatively a compact read.

Your description reminds me a lot of the ES-1 alpha. I'm sure these sound more similar than most the other stats you've listed, although IMO, the ES-1 doesn't come to the technical level of the SR009. Have you heard that one yet?

 

Hey dude I have! Hope its ok to link to my blog. I really like the ES-1a, but I would say in terms of technical performance its more similar to the 007 than the X9000. The value proposition is wayyyyyyyyyy better with the ES-1a though. Thanks for the kind words too.

https://headphonesnstuff.blog/2022/06/01/es-lab-es1a-full-review/

 

I love reading your reviews of esoteric gear that not many people have too. I'd love it if you wrote some more of them or added comparisons, it's great stuff!

 

While I agree that X9000 is the best Stax headphones by far in terms of technicalities, its awkward tonality and imaging was a dealbreaker for me. I would take the original SR-Omega over it, and preferred my 007MK2 to it.

 

Funny how we all enjoy different things. I thought the tonality was a stronger point vs my SR007mk2 (minus the 3khz peak though tbh) when I owned them, and that the imaging was better than the 009.

 

Thanks man that's kind of you to say. I mostly just share the review/thoughts about stuff I spend time with, so I'll make sure to post them as I encounter them. I try to keep things fairly brief as I don't want my reviews to be so long people get bored or find them too long, but I'll try to include a few more comparisons and also if you ever have questions about specific stuff just ask away here, happy to try and share my thoughts if i have heard the headphones in question.

 

I heard the X9000 a few weeks ago at TSAV with the BHSE + Dave setup. Agree with what's being said.

Finally, improved build quality without all the utterly crappy plastic parts. Stax build quality should never have sucked as much as it has for the obscene price tags.

Best bass on a Stax.

Agree warmer and maybe a little thicker than the 009S. I am not sold on this, that headphone had tremendous detail and sparkling clarity, maybe the best in this area, certainly reference. The X9000 seems slightly less concise, and kinda felt less engaging, even though the improved bass was there. There was cohesion, but the cohesion on the 009S seemed perfect. The X9000 treble was I agree also more relaxed, which contributes a bit to the effect.

Overall, it seems like a shift toward users preferences rather than the classic Stax sound.

 

This aligns pretty well with my impressions too, particularly comments on the voicing and bass.

I'm not sure what amps you were using, and I don't know these headphones as well as you, but I'll be that guy and say the amp might have something to do with it.

I had the opportunity to spend an evening alongside an SR007 mk2 (possibly 2.5?) on an SR-X style amp without global negative feedback, and on a transformer coupled SS amp with lots of feedback, in a home setting. My experience is that if the 007 is picky about amps, the X9000 is doubly so. I didn't pick up on the 3kHz thing, but it sounds like the sort of thing one wouldn't necessarily hear in just a short session.

That said, this makes me think of the "Lambda etch" that was common in the thinner 1um membrane Lambdas. It would be a big leap to single out one parameter when comparing two very different products made decades apart, but maybe these thinner membrane drivers are pickier about what's pushing them? Looking forward to hearing your thoughts when your new amps lands.

For what it's worth, I didn't hear the 3kHz issue in the CRBN at all. I also didn't like the CRBN at all.

 

Going from the blog I think either a BHSE and/or KGSSHV Carbon are involved with a iFi Pro iDSD, but +1 @ufospls2 if I could make just one suggestion of your future evaluations it'd be just citing the chain that is being used front-and-center. It's just as relevant for electrostatics as it might be with electrodynamics or planars and helps contextualize the impressions.

 

KGSSHV Carbon with iFi Pro iDSD Signature mostly. I'll circle back to the DIYT2 with the X9000 in the future once the X9000 is more readily available as they are still pretty hard to get a hold of and my T2 is built.

Sure, no probs. I use a bunch of different stuff for conventional headphones and it changes sometimes so I'll try to mention what I've been using in each review going forward. With that being said I do also try to use various supporting gear (at least what I have available at home so its limited) and see how the headphones sound in general across a few different pieces of gear, as well as if one pairing happens to work really well. I find reviews more helpful when they talk about how a headphone in general sounds, rather than with one specific WOW pairing, as then you can kind of get an idea if its going to work for you at home regardless of the supporting gear you are using, whilst still also keeping in mind that specific pairings can always bring about better synergy and special sound as you figure out you personally prefer.

 

I finally could hear the newest Stax SR-X9000 (x9k) and SR-Omega (o1) in a local micro meet a week ago. Off BHSE and 717/CCS, both estats were highly impressive in various ways.

Shortly speaking, X9k aligned very well with modern hifi sounding. I almost felt like I commissioned Stax to build a personalized pair tailored to my desire for analytic nirvana. I’ll probably save up for x9k and keep watching its price trend in the classifieds.

On the other hand, I'd say O1 was more like a re-interpretation of old Senn sounding: namely, super HD600 on steroids in a classic Stax technology. Possibly more sbaf-oriented. I think that, if I heard this two or three years ago, I might prefer this even over X9k.

Specific thoughts below.

SR-Omega:

• More neutral than 007/009 in balance. Tonality closer to HD600 or JAR580 -- obviously upper mid-centric. A bit too much so occasionally to my ears.
• More forwarding and thinner sounding than x9k. More in line with other Stax models.
• Bass extension was very good. Low end presence is even better than x9k.
• Great to excellent technical prowess in any aspect. Particularly in clarity. There were rich details/nuances effortlessly and naturally resolved from music. No worse than 009 to say the least.
• BQ was facepalm bad. Outdated lambda-style plastic headband. And doesn’t feel luxurious by comparison (considering its current prices in classifieds are 1.5 times x9k new pair msrp). Comfort was pretty good though.

SR-X9000:

• Extremely well-balanced for Stax. It’s the best tonality I heard from Stax headphones. Tonally closer to Stealth (confirmed by ABing) but with some nuanced energy in midrange (Stax-ish).
• Neither overly laid-back nor forwarding in upper mids or trebles. Bass behaved like Susvara rather than 007/009. Imagine a slightly lightened Susvara with boosted responsiveness. Better textured, more articulated, and more delineated than O1. Each of the bass, midrange, and treble was my favorite among Stax.
• Every time I switched from O1 to X9k or in reverse direction, I realized: (1) O1 won in a more easily understandable first moment impact, but (2) X9k revealed a bit more information as music was developed. X9k is unequivocally a better tool for music analyses and evaluations.
• Soundstaging was a show highlight. Large in every axis. Great in any of lateral, vertical, and depth definitions. Almost excessive separation and layering, too. Neither distracting nor diffusing for this size -- almost Sus-level size and Stealth-level definition (damn how can they come together?). One of the best 3D experiences I heard from headphones regardless of driver types.
• Even awesome in BQ and comfort.. Holy shit. Stax finally figured out how to make their TOTL remarkable.

Any of the above could be easily influenced by a lot of confounders and biases. I don’t think myself particularly good at short period evaluations. Also, other people in the meeting didn’t necessarily agree with my thoughts. So, please take all of my observations as a grain of salt.