Yeah it’s complicated and I also wasn’t clear when comparing a 5w Champ to a 50w Marshall and saying the Marshall is only two times as loud with ten times the watts. I was basing that on the scientific assumption of watts vs watts being measured through the same speakers, but I wrote champ and Marshall without stipulating that. And while the Marshall there is a lot louder than the champ, my point was that it isn’t ten times as loud. I’d still say it’s very hard to hear the difference between something like 15w output and 35w output when trying to avoid frying the 30w speaker. Staying around one or two watts works though!