I was also wondering the same. With new single DD iems - such as Nightjar Singularity, does the A8000 stand tall?
I can only really compare it to the Fiio FDX for recent DD iems (which is about £600 - a good £1400 less that RRP).
The FDX is the anniversary edition of the Fiio FD7 - basically the same IEM but fancier. Much like the A8000 (A8K), it's a pure beryllium dynamic driver. I believe this makes for a good comparison regardless of the price difference. Before I start I'd like to say that they're both very different IEM's. They share similar qualities due to having pure beryllium drivers, but have different aspects that are enjoyable. The FDX is semi-open with venting at the side of it.
Comparisons are done on a Topping A90/D90 stack, which is known for being entirely neutral.
It has an elevated bass shelf, especially compared to the A8K. The bass has a lot more authority and slam due to this. While it's still surprisingly clean bass, the A8K has cleaner bass but doesn't have as strong of a presence. I'd describe the A8K's bass as safe. It's good enough to enjoy, but it's not what I'd call "bass head" level. According to the crinacle graph, the FDX has elevated bass but slightly rolls off in the sub-bass when compared to the A8K. I'd say this matches up with what I experience.
The FDX has fairly decent sound staging. It's pretty wide and deep for its price point. The stereo imaging is mostly clear but I feel it can be ever so slightly muddied at times depending on the track. That said, it's not bad and doesn't really degrade my listening experience. The A8K has a wider soundstage with really concise, well defined imaging. The FDX is no slouch for it, but the A8K pulls no punches. I feel the sound staging and imaging makes the A8K's bass pretty engaging because of the its level of clarity when contrast with other elements.
When it comes to vocals, they're similarly tuned. You're able to clearly make out what a vocalist is singingwith both. The FDX is warmer than the A8K, which can sometimes be a little too bright for me when it comes to female focals. All in all, I tend to enjoy the FDX vocals more. But take this with a grain of salt since the topping stack is considered bright due to its neutrality. On something like the A&K SP2000 the A8K vocals are tamed enough to not be fatiguing.
The FDX has much warmer sounding treble. I find them more engaging and exciting. Steel string acoustic guitars give me butterflies, and electric guitars have me on the edge of my seat in anticipation. Its presentation rock and pop music is honestly delightful. It's such an enjoyable experience. The A8K doesn't give me that same level of satisfaction when it comes a more "normal" genre, but it's still enjoyable. I certainly don't find myself shying away from these kinds of tracks on it.
On the other hand, the A8K really excels at instruments that you'd find in an orchestral setting. Violins, classical guitars (nylon string, particular body shape), piano, woodwind, and brass are detailed and well presented. You hear the full orchestra and can take in the individual parts with ease. This is as much a benefit of its staging ang imaging as it is its tuning response. The FDX - while still nice - is definitely a sore loser when it comes to pieces that require absolute detail. The A8K is unriviled here. Recordings that are spacious, detailed, and highly technical feel like they were produced for the A8K. Things like blues and jazz are similar in this regard, and play better on the A8K.
The lower part of the brilliance frequencies are recessed on the FDX compared to the A8K around the 10khz region. But then has a sudden boost after that. Symbols, chimes, glockenspiels, etc. really stand out due to this. They're bright without being fatiguing, but that might not be the case for some and I can see that being a pain point.
Dynamics are interesting to compare. Apologies if this comparison is hard to follow - it's hard to explain the dynamics on the A8K. Due to how hyper-detailed the imaging and staging of the A8K is the dyamics are detailed, but due to everything else being just as detailed they don't stand out as much. Basically it does such a good job presenting everything to the point where the dynamics are encompassed in that overall experience. The dynamics are
really good. They're on the same level as everything else. But I feel that unless you pay particular attention to the dynamics it'll sound "flat" because it's up there with everything else in terms of detail retrieval.
The FDX's dynamics on the otherhand are so much easier to notice without paying attention. The difference between something with deep bass - which could have been overpowering given its turning - and something that could be bright such as a chime or a high hat - are clearly heard. Nothings really drowned out when it's quiet. The dynamics aren't quite as good as the A8K's, but it's easier to notice at times. This makes for a really strange comparison because it sounds like I'm talking complete nonsense. I just don't know how else to describe it for the A8K and by extension, how to describe the difference.
This is one of the key differences between the two; the FDX is what I'd call an everyday IEM. It's for when I want to just sit down and really enjoy the music without needing to focus too much on it. The A8K is for when you want understand, break down, and digest the music. If I'm going to a gig and I want to really get worked up beforehand, I'll use the FDX. If I'm looking to sit down after a hard day and lose myself in the music I'll use the A8K's just really listen to it, focusing solely on the track at hand.
In terms of power requirements, the FDX is power hungry at 50ohms. It requires a fair bit of power, and rewards you greatly when you feed it. It scales good with power. The A8K has a 16ohm impedence rating and is "easier" to drive, but scales really well with more power. I feel that on lower gain settings, the A8K's potential is wasted and can sound pretty flat and unappealing. I run both on medium gain using the Topping A90 and found that they both came alive in different ways.
I realise this isn't part of the initial question, but I'd finally like to compare it (a little bit) to the Focal Utopia 2022. I've seen comparisons saying that the A8K is basically a miniature utopia, but I don't feel this is the case. The A8K feels hyper-focused in what it does, for the reasons mentioned above. The Utopia 2022 does almost everything that the A8K does to a much higher degree. Which is probably where the comparison comes from. Although it does so much more than the A8K. It does everything great (and somethings exceptionally). It is more like a marrraige of the best parts of the A8K and the FDX whilst still sounding entirely unique IMO. I've yet to hear a track that I didn't like on the Utopias, but I've heard tracks that I don't like on either/both the FDX and A8K. The comparison is unfair since the Utopia is a flagship £4800 headphone so I don't really like making it. But there's so few pure beryillium DD's out there that it makes sense.
EDIT: I'd like to add that both have 4.4mm cables.
