Since early February I've had the privilege of also owning the Stax SR-X9000 alongside my Shangri-La Jr. Owning it and being able to compare it side-by-side with the SGL Jr allowed me to appreciate the strengths of both headphones. And the SGL Jr carves its own niche alongside the X9000 and holds on to a distinct and desirable presentation even in the face of the Stax's extreme technical prowess. My friend asked if I would sell the Jr to fund the X9000. No, I will not be selling the Jr, it will live alongside the X9000 as co-flagships of my open-back collection.
At a technical level, the SR-X9000 is a better headphone than the SGL Jr by a noticeable margin. More detail retrieval and incisiveness in note transients, particularly in resolving tiny rhythms in music that can often be hidden or smeared by background noise. More body to percussive instruments while retaining the crisp snap of the attack. More bass quantity as well as more apparent bass texture and an incredibly clear rendering of drum resonance/decay. A more even tonal balance with less emphasis in the upper treble, and less of the "breathy" coloration to vocals. A wider soundstage with a greater sense of spatial separation between sound elements and an unparalleled sense of layering of sounds. A sense of openness or "radiative" quality to notes that exceeds even what the SGL Jr can render. In every technical, audiophile sense, the X9000 is a more proficient headphone, and at last a true upgrade over what the SGL Jr can do.
But there is one issue with what the X9000 does. The midrange is too emphasized, which can often result in lead vocals and solo instruments being rendered too far forward spatially. And that one issue is "the root of all flaws" so to speak with the X9000. By pulling vocals and lead instruments forward, it splits them apart from the supporting instruments and background sounds. This is part of the layering and separation I mentioned earlier but taken too far. It's like an exploded view of the music, with each element split apart so that the listener can examine each one in detail. The vocals are also rendered too wide spatially, like the singer's mouth is stretched out between my eyeballs (lol). But this only occurs if the track is mastered to allow it. If the track doesn't have a forward-mixed lead vocal/instrument, then the X9000 can sound distant and recessed and I need to crank the volume to compensate. This occurs most often in orchestral works and soundtracks. The forwardness of the midrange can also cause the sense of forward depth to collapse and result in a flat and 2D image. This effect is exacerbated by some gear pairings which I'll mention later.
In comparison, the SGL Jr has less technical capability, but everything it does is cohesive. It renders a sense of a concert hall, and it sticks to that character across different tracks. It doesn't vary wildly in its presentation of sound from track to track. The soundstage isn't as wide, but there's a better definition of space within those bounds. The X9000 in comparison has what I call the "illusion of boundless space" since the layering makes it hard for me to lock on to where the stage boundaries are, so it can seem larger than it is. But sometimes this illusion is destroyed due to the forwardness of the X9000's midrange making it less consistent with its forward spatial depth than the SGL Jr. Vocals on the SGL Jr are slightly recessed overall, but still imaged in front of the backing instruments. The vocals are tonally colored with that breathy character, but that heightens the illusion that they're on a stage in front of me and singing into a large open space. By having greater forward distance to the vocals, it avoids making vocals too forward and wide. There's some loss of detail due to significant dips at 5.5K and 14K on the Jr which smears the attack of hi-hats and some cymbals, but it keeps them cohesive within the sound image rather than highlighting and separating them out like what the Staxen (L700mk2 and X9000) do. The Jr sacrifices that perception of crisp detail for softer hi-hats that add atmosphere and ambience to the sound without distracting the listener.
Percussion is an interesting case. While the X9000 balances the attack (the "crack" of the stick hitting the drumhead) with the body (the "whump" of the drum's resonance and decay) better with noticeably better body to percussion notes in addition to greater bass quantity, the emphasized attack and air of the SGL Jr results in cymbals, toms, and hi-hats sounding very tight, punchy, snappy, and airy, and I often find those qualities subjectively pleasing. One example is "Rest of My Life (feat. Medyk)" by Culture Code where the ending drop (from 2:00 to 2:46) includes fast and punchy electronic snares which sound so energetic on the Jr even though I hear more body and texture on the X9000. As an aside, I don't think I've reached the limit of what I can hear from the SGL Jr. When I heard the Jr on the BHSE + MDave setup at a recent meet, it had noticeably more bass presence on that setup than on my Ferrum Erco + CCS-modded SRM-006tS setup that I have. The Jr is less sensitive than the X9000 and I need to turn the volume up higher when I switch to the Jr. I'd love to upgrade to a more powerful amp for the SGL Jr.
A curious thing I found is that despite the X9000 and SGL Jr having overall pretty similar sonic characters, they're different enough that the gear synergies are different. Because the Jr has a smoother and softer sound with a recessed midrange, it pairs well with punchy source gear. I really like my Ferrum Erco with the Jr and I think its dynamic nature enhances the punch that it provides to percussion, brings the midrange forward, and adds a bit more bite to an otherwise extremely smooth upper treble. But those qualities are detrimental to the X9000. The Stax doesn't need a more forward midrange, and the added midrange dynamics actually result in that soundstage collapse I mentioned earlier where vocals get so forward that the entire image seems 2D, like notes are places on a line between my ears. The X9000 thus seems to benefit from less forward gear that emphasizes space. I did a lengthy pre-purchase demo of the X9000 on a Chord DAC and perhaps that is a path that I could go down. I would like to build another electrostatic setup optimized for the X9000 as my current one with the Erco and 006t is tailored for the SGL Jr, but that will have to wait for a few months. In any case, it seems that the X9000 is more synergy-sensitive than most other headphones, so I might as well take my time to find the right combo.
Anyways, that's my comparison of these two headphones that I enjoy greatly. The SR-X9000 is the more technically impressive headphone, and if we're tallying up points like a competition, it would easily win that contest. But going back to the SGL Jr is like coming back home after staying at a 5-star hotel. Sure, the linens aren't the finest Egyptian cotton, the bathroom floor isn't heated marble, and the toiletries aren't from fancy brands, but it feels like home; it feels right.
