Watts, and clarity.

Watts on second. 

Thanks for the responses, although judging the context there are some who may not understand "all other things in a stereo system being equal."

Let me second that Eric is a pretty swell guy. I think @clearthink confused him with someone else or someone woke up on the wrong side of the bed. Coffee time. ☕️

All the best,
Nonoise

Anyway at about 6:06 into the video Bob Carver discusses his friend that did the testing.

So a video of Bob Carver in the 1980's saying he heard from some guy .... :)

Credible claims tend to be reproduced, especially when they end up in selling bigger, more expensive equipment. On top of that, we have our own experience, and that of many other audiophiles here. If power were the limiting factor for accuracy I think we'd hear more of it.

Based on age, lack of detailed description of the experiment, and lack of corroboration of a very easy to duplicate claim this claim does not pass my smell test.

As with all things in science and engineering, I leave the door open to more research.

Best,
E

Some clarity, for those that care(knowledge is power): (https://geoffthegreygeek.com/amplifier-power/) (http://www.sengpielaudio.com/calculator-levelchange.htm) (https://www.gcaudio.com/tips-tricks/the-relationship-of-voltage-loudness-power-and-decibels/)  (depends how you look at it)