Is there another way to measure small changes that an alternative mat may produce? An approach that might work for comparing other small changes like new cables or other components?
Not as far as I know.
Quick a/b swapping is best as far as I can tell.
On the few occasions I’ve got friends to chime in with their impressions the results haven’t always been helpful.
Sometimes they’ll agree, and sometimes they won’t.
Even worse, after they tell you of their impressions you tend to start hearing them too.
Whereas with a quick a/b it’s difficult to not hear any clear differences, if they exist.
A similar analogy for example might be any comparison of 2 different things, eg Budweiser or Heineken, Coke or Pepsi, Marilyn Monroe or Jane Russell etc.
What your memory tells you that you think you prefer might well be at odds with what a direct comparison tells you.
Whether we like it or not our memory does fade and it can certainly play tricks on us.
This has been tested time and time again.
I’d love a photographic / eidetic memory but the best I can do is a passable recreation if a d when I’m in the correct mood.
So it’s probably best to rely on memory as little as possible and more on immediate impressions when making direct comparisons.
I can understand you wanting to know for sure, I used to too, but nowadays, unless the differences are fairly obvious, I don’t see the point.
I spent far too much time with nonsense such as turning the turntable mat upside down and turning the drive belt inside out (as advised by such parties as Linn etc) to bother with such stuff nowadays.
Did any of it make a difference?
Maybe it did theoretically, maybe it was one that could be distinguished by some advanced measuring device, but it certainly wasn’t one that I could hear.
A blind listening test is usually even more unsympathetic to whatever preconceived notions we may have regarding sonic performance.