Hi, good point.
Just from my perspective, my answer would be this. We know we can hear distortion, noise and changes in frequency response. If there are another factors, they remain undiscovered.
We also know the limits of human audibility for each of those areas, as properly scientifically lab tested.
So that’s my position. Anything within those borders, that’s what I call transparent, and will do so until tests of the same standards either identify a new area, or show that the thresholds are wrong.
But I’m always happy to hear the experiences of others, whatever their perspective.
So over to you lot with Ultras.