[Chefguru]

Anyways, back to the SR-X9000. I went to The Source AV outside LA to try the X9000, but alas, it wasn't there! The store had been burglarized a few weeks ago and the X9K was stolen in the robbery! It took an hour and a half to get there from Pasadena, so it was quite disappointing (for both me and TSAV). I had hoped for a second, more critical listen to follow up on my CAF experience and see if I really wanted to buy it. But I had a good time anyways listening to other headphones. If you see any suspiciously cheap X9Ks on the used market, it might be worth double-checking its origin.

I also learned a few interesting things about the business backend of Stax. According to Jason at TSAV, only 12 SR-X9K units are shipped to the US every 6 months. The vast majority of produced X9Ks are kept in Japan for the domestic market. Only 6 units have been shipped to Canadian dealers since the headphone was released two years ago. Honestly, this makes me tempted to import, because it seems they are relatively plentiful in Japan and the yen is so weak compared to USD right now that I'm basically getting 30% off the list price.

Another dealer comment on a different forum was that in late July of this year, Stax shipped their 1000th X9000. It took just under two years to build 1000 units.

Horrible to hear about the Source getting robbed!
I wouldn't import an x9k. My first set (and many here) have had severe channel imbalances.

 

[gammi]

It would already be apparent from looking at these Stax headphones' drivers and HiFiMan's that they do not have much damping beyond driver tensioning and air resistance. My theory has been that for absolute "speed" or "cleanness" of sound, you would want a cumulative spectral decay (CSD) that is as clean as possible (though said decay may only be audible when playing transients really loud; I don't think the Stax SRM-T8000 could play said transients to the point of hearing audible decay components). The Meze Elite with its outer-side (back volume) damping had a cleaner CSD than the HiFiMan Arya Stealth which itself had a cleaner CSD than both the Stax SR-X9000 and Sennheiser HE-1 while my closed-back Audio-Technica ATH-M50xBT and Jabra Elite 85h had the cleanest CSDs (virtually nothing in the midrange above the noise floor), but one assessment consistent with that measure as well as what I have heard out of some headphones that I haven't measured is that CSD cleanness tends to be correlated with increased driver damping and hence duller transients. E.g. The DCA Expanse when I auditioned it had very clean transient decay (when listening to http://pcfarina.eng.unipr.it/Acustica-samples/Dirac.wav, a single 0 dBFS sample at 48 kHz sampling rate, very loud), but felt the dullest out of the headphones I auditioned per all the damping and tuning materials used. So "speed" per the sense of incisiveness or how rapidly the driver accelerates does not always correlate with how rapidly the driver comes to a stop. The Final Audio D8000 Pro when I listened to said transients seemed like a combination of reasonable transient sharpness and very good transient cleanness. Another theory I have is that "impact" or transient sharpness may be related to the smoothness of the bass group delay measurement, of which among those headphones I have measured, the HiFiMan Arya Stealth had a particularly smooth bass group delay, its indeed being the most incisive headphone I've heard to date (until I can drive an estat loud enough for a better comparison).

tl;dr: The Stax SR-X9000 is an exceptional headphone with tuning performance, driver control, and EQability rivaling the Sennheiser HE-1, whereby you should all be very happy owners or aspirants.

Awesome post thank you. Your talk about dullness vs cleanliness inspired me to make a drawing to illustrate for everyone. It's stuff like this that many don't realize can make two headphones with the same FR curve sound quite different, otherwise we'd all be using HD650s

 

[MrHaelscheir]

Awesome post thank you. Your talk about dullness vs cleanliness inspired me to make a drawing to illustrate for everyone. It's stuff like this that many don't realize can make two headphones with the same FR curve sound quite different, otherwise we'd all be using HD650s

"Dull" was more like the following for the DT1990 Pro, though I haven't heard one myself:
https://diyaudioheaven.wordpress.com/headphones/measurements/brands-a-i/dt-1990-pro/

And note that that perfect step response can only occur with infinite bandwidth.
Then "impactful" could be like the following:
https://diyaudioheaven.wordpress.com/headphones/measurements/audeze/lcd-4/

 

[gammi]

For sure, the curves could take a lot of different shapes. I would love it if the the headphone space spent more time discussing how these differences affect sound, we still have a lot to cover. I'm a computer engineer like you as well, so I appreciate objective measurements but the reason why I'm here and not ASR is because I don't think the space has collectively figured out what the best objective measures are yet.

 

[MrHaelscheir]

For sure, the curves could take a lot of different shapes. I would love it if the the headphone space spent more time discussing how these differences affect sound, we still have a lot to cover. I'm a computer engineer like you as well, so I appreciate objective measurements but the reason why I'm here and not ASR is because I don't think the space has collectively figured out what the best objective measures are yet.

I think SBAF is the middle-ground where measurements are discussed a lot, but with lots of consideration of the subjective.

 

[gammi]

As for DCA's distortion measurements, at least based off of Jude's measurements, it is "merely" competitive with the Meze Elite and Audeze CRBN, both surely having sharper subjective transient effects. As for ASR's measurements, I suppose the 009S does have worse lower midrange distortion than the DCA Expanse. I can say that the Sennheiser HE-1 had decent impact and transient sharpness.

Just want to add that I sent my personal Expanse to Mitch at Accurate Sound to generate an EQ filter for it and he replied back saying it was the lowest distortion he's ever measured. My Utopia was second (I guess that stiff beryllium driver works)

He hasn't measured the Elite or CRBN though based on what filters he has available.
https://accuratesound.ca/store/#filter

 

[MrHaelscheir]

Just want to add that I sent my personal Expanse to Mitch at Accurate Sound to generate an EQ filter for it and he replied back saying it was the lowest distortion he's ever measured. My Utopia was second (I guess that stiff beryllium driver works)

He hasn't measured the Elite or CRBN though based on what filters he has available.
https://accuratesound.ca/store/#filter

I think I had read of Mitch's service or provision of convolution filters back in the Meze Elite thread, or that was from someone else. Anyways, I much prefer using in-ear microphones at home to ensure a proper match with my own ears as individuals may hear peaks in different locations; e.g. if per https://accuratesound.ca/headphone-calibration/, they are conducting those EQ fine-tunings themselves, I would much rather do it myself while listening to sine sweeps and playing with peaking filters. I have yet to confirm whether convolution filters incur audible phase distortions compared to minimum-phase EQ. At least through my binaural head-tracking setup and its simulated crossfeed and specific phase manipulations, I hear mild transient smearing or an additional "chp" quality when listening to the isolated Dirac delta function.

Update: Another comment I have is that it seems like they are extracting the headphone's transfer function and EQing that to be perfectly flat. If they are in fact doing that, the problem is that you at the eardrum would effectively be receiving the "perfect" HRTF response, but for sound sources of 90-degree incidence as opposed to the 30-degree incidence typical of stereo mixing. If for "transparency", we want the perfect HRTF response for a classical stereo triangle in an anechoic room, we would need to measure and EQ like in https://www.head-fi.org/threads/in-...frs-are-indeed-identical.970202/post-17801518 (post #61), and apply the correct HRTF-based crossfeed. It was through the kit from https://www.earfish.eu/ that I was able to take my measurements, though they being university staff may have long communication overheads.

 

[zeitlos]

I have a STAX X9000 and a Paltauf Headphone amp for Stax. I am now wondering, if the STAX SRM T-8000 would be the better choice for the X9000? Is there anyone with an opinion or even experience of both amplifiers?

 

[Rhamnetin]

The T8000 isn't really recommended as some less expensive amps like the KGSSHV Carbon are known to perform significantly better.

 

[SolarCetacean]

Regarding Stax amps vs 3rd party, I've heard of people actually preferring the Stax amp presentation vs the KGSSHV or BHSE. Impressions I've seen (one was from CanJam SoCal this year) was that the Stax amps made the sound more "floaty" or "ethereal" while the BHSE made things more "grounded" with better bass and treble extension, but it lost that "floating" character on the X9K. The BHSE would be more neutral and technically better, but synergy and preferences are also a thing. Definitely something to demo yourself before committing to a purchase.

I've scheduled a listening session for the X9K and BHSE at HeadAmp for this Friday. I'm very eager to listen to that combo again and I'll also be comparing it against the DCA Corina. Maybe I could ask for the Stax SRM-700T to compare how it sounds on a stock Stax amplifier. I plan for this session to be longer and more focused, with a more critical mindset. My previous impressions were glowing and I suspect part of that was just the first-listen euphoria, but I did note some potential issues in the midrange and imaging, which @number1sixerfan helpfully described as a lack of cohesiveness in the presentation. When I went back home and listened to my SGL Jr, I noted how the sound image was very cohesive; everything sounded "in the right place" relative to everything else in the soundstage. Will this relative lack of cohesiveness on the X9K bother me? Will it outweigh the other positive attributes that I perceived? At the same time, I don't want this demo to purely be a nitpicking exercise. I think I'll have enough time to just listen for enjoyment there, so that way I can see how the X9K performs when I'm in a different, less evaluative, state of mind.

 

[MrHaelscheir]

Regarding Stax amps vs 3rd party, I've heard of people actually preferring the Stax amp presentation vs the KGSSHV or BHSE. Impressions I've seen (one was from CanJam SoCal this year) was that the Stax amps made the sound more "floaty" or "ethereal" while the BHSE made things more "grounded" with better bass and treble extension, but it lost that "floating" character on the X9K. The BHSE would be more neutral and technically better, but synergy and preferences are also a thing. Definitely something to demo yourself before committing to a purchase.

I've scheduled a listening session for the X9K and BHSE at HeadAmp for this Friday. I'm very eager to listen to that combo again and I'll also be comparing it against the DCA Corina. Maybe I could ask for the Stax SRM-700T to compare how it sounds on a stock Stax amplifier. I plan for this session to be longer and more focused, with a more critical mindset. My previous impressions were glowing and I suspect part of that was just the first-listen euphoria, but I did note some potential issues in the midrange and imaging, which @number1sixerfan helpfully described as a lack of cohesiveness in the presentation. When I went back home and listened to my SGL Jr, I noted how the sound image was very cohesive; everything sounded "in the right place" relative to everything else in the soundstage. Will this relative lack of cohesiveness on the X9K bother me? Will it outweigh the other positive attributes that I perceived? At the same time, I don't want this demo to purely be a nitpicking exercise. I think I'll have enough time to just listen for enjoyment there, so that way I can see how the X9K performs when I'm in a different, less evaluative, state of mind.

For you, how do far-panned sound sources image through the X9000 (or Shangri-La Jr.) through these different amps? As for the T8000, I hadn't found anything notable about the presentation (I hadn't heard the X9000 on any other amp) other than that with how I experience headphones without crossfeed, far-panned sources would image noticeably right from the drivers, which I also experience with any other headphones unless the track incorporates some special effects, the X9000 just happening to have the drivers yet closer to my ears. I after getting speakers and using binaural head-tracking with my measured HRTF cannot shake the inherent imaging distortions applied by virtually any headphone to tracks mixed for traditional stereo triangles, though I admit some of those distorted around-your-head presentations can be interesting.

Anyways, regarding "image cohesiveness", I can comment that HRTF mismatches can contribute to some weird imaging in the speaker simulation with some higher-frequency content remaining heavily panned, or in the case of using APL Virtuoso's default HRTFs, playing vividly above my head while the rest remains in front of me.

 

[number1sixerfan]

Regarding Stax amps vs 3rd party, I've heard of people actually preferring the Stax amp presentation vs the KGSSHV or BHSE. Impressions I've seen (one was from CanJam SoCal this year) was that the Stax amps made the sound more "floaty" or "ethereal" while the BHSE made things more "grounded" with better bass and treble extension, but it lost that "floating" character on the X9K. The BHSE would be more neutral and technically better, but synergy and preferences are also a thing. Definitely something to demo yourself before committing to a purchase.

I've scheduled a listening session for the X9K and BHSE at HeadAmp for this Friday. I'm very eager to listen to that combo again and I'll also be comparing it against the DCA Corina. Maybe I could ask for the Stax SRM-700T to compare how it sounds on a stock Stax amplifier. I plan for this session to be longer and more focused, with a more critical mindset. My previous impressions were glowing and I suspect part of that was just the first-listen euphoria, but I did note some potential issues in the midrange and imaging, which @number1sixerfan helpfully described as a lack of cohesiveness in the presentation. When I went back home and listened to my SGL Jr, I noted how the sound image was very cohesive; everything sounded "in the right place" relative to everything else in the soundstage. Will this relative lack of cohesiveness on the X9K bother me? Will it outweigh the other positive attributes that I perceived? At the same time, I don't want this demo to purely be a nitpicking exercise. I think I'll have enough time to just listen for enjoyment there, so that way I can see how the X9K performs when I'm in a different, less evaluative, state of mind.

Will be looking forward to the impressions here. I'll say that the last time I heard them, they were very good. I walked away impressed, even though I still saw the 1 or 2 issues I had with them before. If I didn't have the SGL Sr., I'd definitely own them again. Will be interested in hearing your second take on the Corina. I heard them on the BHSE and I thought they were pretty good; not groundbreaking, but pretty solid. I thought a pretty good offering with a different flavor but a similar level of the 007 and 009. Didn't sound as resolving as the 009, but also was a bit smoother.

 

[SolarCetacean]

Will be interested in hearing your second take on the Corina.

Technically, it will be my third take on that one. I listened to it the second time at TSAV last week on the Woo 3ES + Chord DAVE, and I wasn't particularly impressed with it. Folks in the Corina thread convinced me that I needed to hear it on the BHSE to really hear what it's capable of, so I'll do so in this coming demo. This is going to thus be a rematch of X9K vs Corina, but this time on the BHSE vs the LTA Z10e that I had at CAF. I'll freely admit that I have a bias towards more sparkly, airier, more open-sounding and separated/layered headphones, and that's not what the Corina is meant to sound like, so I'm already biased against its sound. But I'll try to give the Corina a fair shake. In fact, I'll probably listen to the Corina first, because I suspect that consciously or not, the first headphone I try in a listening session sets my expectations.

 

[number1sixerfan]

Technically, it will be my third take on that one. I listened to it the second time at TSAV last week on the Woo 3ES + Chord DAVE, and I wasn't particularly impressed with it. Folks in the Corina thread convinced me that I needed to hear it on the BHSE to really hear what it's capable of, so I'll do so in this coming demo. This is going to thus be a rematch of X9K vs Corina, but this time on the BHSE vs the LTA Z10e that I had at CAF. I'll freely admit that I have a bias towards more sparkly, airier, more open-sounding and separated/layered headphones, and that's not what the Corina is meant to sound like, so I'm already biased against its sound. But I'll try to give the Corina a fair shake. In fact, I'll probably listen to the Corina first, because I suspect that consciously or not, the first headphone I try in a listening session sets my expectations.

Yea, based on feedback I've heard from others with the 3ES and just knowing wow products pretty well, I am extremely doubtful that there will be some major difference in the performance of the Corina on the BHSE vs. the 3ES. Everything else regarding the build is true, but it doesn't perform (apparently) like some crap stax amp. Secondly, the bolded part was also my experience when I heard it with the BHSE. It simply doesn't shine in those areas and is more similar to the Carbon in that regard. If that was your sticking point, and likely why I wasn't "wow"d by it either, that is unlikely to change. But I do think you can still give it a fair shake and assess it for what it is. At least you'll be able to cross amplification off the list as any root issue.

I think a lot more people that aren't traditional stat lovers enjoy a smooth tonality at the sake of air, layering and resolution. There's more of a market now for that, and I think why things like the Carbon, Corina, etc. are popping up. For me, I'll always prefer that the traditional strengths of stats shine through in any stat--especially a TOTL offering.

 

[gammi]

Technically, it will be my third take on that one. I listened to it the second time at TSAV last week on the Woo 3ES + Chord DAVE, and I wasn't particularly impressed with it. Folks in the Corina thread convinced me that I needed to hear it on the BHSE to really hear what it's capable of, so I'll do so in this coming demo. This is going to thus be a rematch of X9K vs Corina, but this time on the BHSE vs the LTA Z10e that I had at CAF. I'll freely admit that I have a bias towards more sparkly, airier, more open-sounding and separated/layered headphones, and that's not what the Corina is meant to sound like, so I'm already biased against its sound. But I'll try to give the Corina a fair shake. In fact, I'll probably listen to the Corina first, because I suspect that consciously or not, the first headphone I try in a listening session sets my expectations.

FWIW my first time hearing both the Corina and X9000 was on a BHSE and Grand Cayman at the 2023 NYC CanJam and I had the same impression as you and sixerfan on those TOTL amps, the Corina simply isn't a sparkly/airy headphone, it sounds more like a planar imo. X9000 however immediately made an impression on me. It was the only thing I put on my head at the show where I immediately went ooooohhhhhh. It was the one headphone there that I felt was a clear step above all my other headphones. About 3 months later I bought one cause I just couldn't shake that impression it made.

Now I know shows aren't a good testing environment, BUT, HeadAmp did have their own room AND that same sensation of something "special" I got at the show (that I didn't get with Corina) I also get at home with my personal X9000 now, so it's clear I was at least hearing that correctly. I even liked the X9000 over the Shangri-La Sr but I think that was more a personal thing that I liked the presentation better.

Here's some pics of the exact setup I listened to:
https://www.headphonesty.com/2023/03/canjam-nyc-2023/