I see absolutely no "controversy" at all in these opinions (of course, being also 'packed' in it).
Bit of a clue as to why: it's must be a weird coincidence that
all of these opinions perfectly mirror each other pointing at the same exact things.
Even though all chains are somewhat different confirming the assessment that no mod, chain tweak, EQ or whatever will
fundamentally change how something is perceived, it just makes something much more liveable). And let's not forget people voting with their wallets either, reselling - if it was as good as some people say "without controversy", then resale value should not substantially change over time (applies to any 'flagship' in general, some more hyped than others, and the X9000 - or Stax in general - certainly has less of that than certain other brands). Just because almost none of those people state their opinion (publicly), their takes are just as valid like others endlessly praising on forums.
“Everybody talks when they have nothing to say” (
Fiona Apple in a 1997 interview, how true it is now in a social media world...)
The term "analytical listener" makes my hairs stand up, but I think up to a point, that's kind of the type who like (or just don't mind as an addition) 'modern' Stax presentation in general, where internal reflections in the housings, diaphragm mass and all sorts of other technical stuff has been meticulously corrected (well, they could do a hell of a lot more designing a Lambda with bass extension and balanced FR again, what they do instead is not disclose any FR measurements anymore...).
As a result, detail IS more forward than in past models and it looks like there is also a certain degree of brightness that has to come as a byproduct of increasing clarity - and I don't personally think
either is a good thing in pursuit of a more natural (non-bothersome, "disappearing") sound.
I hear every crosstalk with various instruments the mics pick up in every channel. Everything very 'sliced' and 'precise'.
That's great, very impressive (sometimes, also, there are certainly recordings will take full advantage of all this), unless...
... unless I would rather focus on the melody itself, the "essentials", which brings in the mood, the momentum, the elegance, all of those "subjective" things that makes us feel happy, sad, impressed, surprised, and so on. Immersing in music.
But, instead, it brings other things into focus, in kind of an exaggerated and at times slightly forced way.
A lot of those extra informations are like sensor dust on pictures.
They are not there to be seen or heard. They are there to be cloned out in post or muted.
Or at least it is better that they are blurry and melted into the background rather than sharp in the foreground.
Like film grain, we don't seem to mind that too much. (Vinyl noise on the other hand, that could be a different discussion...)
So, inevitably, I felt unmoved - too many times. I don't perceive it as a very "organic" ("filmic") sound.
That's how I perceived it, it's fine. For people who think "more is more", it probably works and I certainly would not mind having as an addition.
But in my mind at least, the NB Lambda will always be the best thing that they've ever did, which is kind of a polar opposite in almost everything is does. No high bias, super-high-res, massively sized diaphragm, wide cabling, exotic materials, kind of crude to have physical damping crammed in the housing, limiting extension or bass linearity, etc. And yet...
...in my mind, by simply shrinking (simplifying!) the NB Sigma design, they've accidentally made a masterpiece of a headphone (with an "accidentally good FR") for people who tend to appreciate
music itself the most, yet still presenting it at a faithfully high 'technical' level, focusing on the 'basics' on what I consider to be a more faithful (less artificial, depending on the viewpoint, I don't want to say the NB is "real", of course it is not, I know every single one of its ["controversial"] faults all too well, yet it just feels a "prettier, more focused, more involving dreamland" than other Staxes with certain aspects that are of utmost importance to my perception of the sound.
Moving away from this level and to my ears, it is basically impossible to keep the same level of purity (musicality, involvement) in the sound.
The Stax Omega (flagship) series sound is much more extended, grandiose, dimensional, holographic, transparent type of sound with higher dynamics and more fullness.
But this is always going to be more distant and nuance-focused. Therefore, it can never feel as plain, simple, tactile, intimate and faithful, a bit more "hi-fi" like (not necessarily in a bad way). But the fact of the matter to me is
many times more money spent does not automatically equal to "higher-end sound". Still dying to hear the "uncontroversial" T2, because on the amp front it might be a clear upgrade, but it would be interesting to evaluate whether 4-5x money over a used Carbon is justifiable or not and with specific models and whether the Carbon is still "good enough" or "not anymore".
A few people pointed out a feeling of recession in the midrange. I do agree, and I think that up to a point it's there on any big Stax (while NB Lambda is the opposite but that's why I love it, never loses grip on the human element of the music instead of "getting lost" in other important or distracting details, it's not a "busy" sound) so a wire with gain type of amp might not be the ultimate solution despite being an ideal amp on paper by design.
Alternatively, we can also move further down in the chain and having a sound "even more pure" but also bit murky and too coloured. SR-5 Gold is not something I hold in high regards amongst all the other greats, but it's no risk to transport either, so I did carry it to a trip this year with the little SRA-3S amp just to have something in the evenings and once I got used to its style, I still liked it. Does not matter that it's a "low-end" model, still does certain things much more distinctively than an X9000.