Normally I just use my PS Audio sprout 100, but the full list of components I'm using are on the previous page. Its definitely a big step up from what I normally listen to, its basically $650 vs $10,000-ish. (Not including the cost of speakers)
I would definitely like to do the same tests again but with my Sprout to see what difference is made on more entry to mid level integrated hardware. Maybe I can do that sometime this week.
It made a bigger difference than I was expecting, but a lot of the differences tend to be when listening to parts of songs i know have wide soundstage or have effects that are easy to distinguish between hardware/speakers.
In most cases, the changes were obvious, the last test was a lot closer, aside from the extra punch in the midrange and veiled treble.
The generic cable was a harsh experience, and the AudioArt cable was definitely a step up from that, being more balanced overall but still falling short of the B6 Prototype and B24
That said, you are largely correct. There are a lot of factors that will go into what you can/can't hear; speaker placement/design, gear, source, etc. On top of also knowing what to listen for, esp when it comes soundstage, imaging, layering, clarity in songs your familiar with.
I wouldn't say you need to spend tons on hardware to get similar benefits, but its likely that those changes are definitely going be more noticeable the better the quality of your hardware.
Funnily enough, my living room is completely untreated, and is still unfurnished, its just a bunch of mostly empty boxes sitting in a couple corners, and for me im not even sure I'm noticing a difference in noise floor, mostly cuz my test music isnt really good enough for that.. lol
It's not an ideal setup, but the differences are certainly noticable.
It's not about if the world us flat or round, but is a difference observable. I noticed it when I installed tube connectors on my XLS, I noticed it when I upgraded to the 16-strand cable kit. It was a lot less noticeable on the B6 power cable, but it was also down to the song if I noticed it or not, cuz much of my music isn't well recorded/mixed and often played over Bluetooth... lol
But I'll definitely look into swapping back to my Sprout for a few days and report back my findings