What's the point of arguing with folks here anyway? They will stick their fingers to their ears, singing "la la la la" whenever hearing anything not fitting their world view anyway.
If the cable makes no different, then it shouldn't be so darn hard to find a replacement cable that does not mess up the sound of the Andromeda 2020, or even the U12T. Now, if the sound can go down, can go up? I don't know, I haven't heard any of my IEMs improved by a changing cable, just degraded or unchanged. But the fact that it can go down already dispels the idea "zero difference." Whether it can go "up" is something I'll remain curious and test for myself when there is a chance.
For the Andro, Purrin measured this(green is 2020's version impedance)
So, yeah, almost anything from amp to cable has the ability to, at the very least, make some audible FR change. And that's only part of the fun, as many devices will cry when presented to below 5ohm load. For those, a cable with an extra ohm could be a sort of electrical salvation(in this scenario, the typically worse cables with higher impedance would probably improve fidelity, but also boost the 6 to 9kHz with the subjective impact that would have).
This IEM is among a short list of forever brought up examples of "everything sounds different" for a reason, and the reason is that ludicrous impedance curve.
I've heard that IEM and thought it was really nice, but there is no way I'm giving money for something like that. I already didn't buy the SE846 that I really enjoyed (plus I like that small Shure shape), because the impedance curve was going from 16 to a little below 5ohm. That Andro does even worse.
About the U12T, to this day I don't know if the big sound changes are an urban legend born from guys with too much imagination, or if there is indeed something within all the unusual stuff in their design that is not nearly as stable as it should be. The super proprietary LID technology (let's call it a cheap voltage divider, given what it does) should in principle greatly minimize the impact of amps or cables having a different impedance from the last one. Is it enough? Does it have other issues? IDK. I haven't seen anybody look that up seriously in a few scenarios, and I haven't tried it myself.
I'm not saying, nothing happens, it is one weird IEM in various aspects. I'm saying I do not trust online people claiming to know what they're hearing, and I need more than a mob of opinionated people to decide when something is factual.
Anyway, back to cables and possible sound change being audible. Of course, it's possible. A possibility and specific associated circumstances however do not magically prove anybody with a gut feeling and bad testing routines to be right all the time. That fundamental aspect of logic is being ignored by anybody who finds it more convenient to do things the wrong but easy way.
Similarly, I don't understand how so many people fall for the dumbest groupthink fallacy in the book. I heard differences in some IEMs when switching between some cables. I have measured IEMs that would be expected to audibly different in FR (above 1dB change over a significant frequency range) simply with a change from 0.1 to 1ohm at the source, and have measured more than 1ohm difference between some cables. Does that make me support any random guy online claiming to have heard whatever change for whatever reason he cherry-picked as the cause? No!!!!! One does not justify the other. It does not have to, and really it shouldn't. For each very real and very obvious sound difference scenario, I'm confident we can find a dozen people who just fooled themselves one way or another. And then we surely can find a few others who do hear a real sound change, but they then draw the wrong conclusion about what caused it.
Too many people support whatever BS is being posted, so long as the guy is "on their side". Let's do better than that and give value to the qualitative demonstration of fact instead of empty claims, overconfidence, pander and demagogy.
I know, me saying that when the replies to this particular thread have been nothing but trolling, is mighty ironic. In some ways, that makes me consider joining OP's side, if only for the sake of not being associated with the trolls. But once again, it's not about what's easy, it's not about crowd pleasing or getting likes. It most certainly is not something that should be dumbed-down into only 2 black or white, all or nothing choices. It's about the facts and how much confidence we should put behind what's presented without evidence (the entirety of OP's post lacks supporting evidence).
Testing for audible differences between 2 specific cables is more complicated and demanding than most people imagine. As you rightfully mentioned, the IEM in use tends to be mighty significant for the outcome. OP didn't even consider that information to be relevant to his little case... It's only one of many problems in his 'experiment', but it's already enough for me to suspect that, for now, he is probably not qualified to weigh in on cable testing.
Not that I think any reviewers usually talking about the sound differences of cables are qualified (maybe there is one, and I just haven't seen him?). Those guys usually humiliate themselves and ruin whatever credibility they built on other subjects. I find that disappointing and counterproductive.
