Correct.You seem to be saying a reviewer as a human is incapable of sorting out a products performance if any change outside setting the new product into a place where something else sat and touching nothing else is the baseline. That is in essence saying humans are too simple in their overall capacities to comprehend and analyze much ouside a simple change. Maybe????
It is possible the reviewer may derive a more or less accurate opinion as based upon their past reference if to much is changed. This could definitely be the case with a wholesale change such as new electrical infrastructure, a new rack, a new TT. There very well may be a transition or time of acclimation to the new environment. But we dont live in a stagnant world. Reviewers hear things they like and buy them to keep as their reference. Maybe this is a good thing as they are constantly adjusting their base understanding. They might at times look back and realize something was better or worse than they thought at the time. Maybe its a human fallacy. But how do you escape that. We can't keep everything the same forever. That negates growth.
This isn’t an intellectual exercise. This is obvious and cut and dry. Let’s explore what you experienced “at Fremers, and other places, changing the electrical infrastructure can radically alter equipment performance“ to drive the point home:
You did the electrical work and then “After the change, I was stunned by the speaker and loved them”. Did the electrical work and electrical power changes optimize the source component to really extract the most out of the media? Or was it that the new clean power allowed the preamplifier to shine and allow it to be “set it up as best as you can”? Or did the new electrical power allow the amplifier to be “optimized” and produce its full potential? It certainly did not effect the speaker‘s power as I assume that the speakers are passive and not powered speakers but yet here you are attributing the changes in electrical power to the speaker’s performance as you were “stunned by the speaker and loved them”. Do you see what I mean now?
The focus of equipment reviews are the component under assessment and nothing else. The value in an equipment review is to tell you as much as it can about the component under analysis.
Here is how the reviewer can escape “We can't keep everything the same forever.”: 1) By establishing a baseline, in other words a “reference“ basis for his comments, 2) By being consistent with his methods and processes and procedures, and 3) By understanding that his observation are of no value in “absolute” terms but can offer value to the readers in “relative” terms.
The reviewer does not have to stay stagnant, but he must reestablish a baseline and maintain consistency with his efforts from the past to provide value to his readers and keep comments in the context of and focused on the equipmemt under review.