Do 45 rpm 12" LPs really sound better than 33 rpm?

Your “tests” prove nothing that anyone else can use for guidance.

I'm glad most people agreed with Mike Lavigne, even though I said it first.  I don't care if Mike gets the credit; Mike is good company in a discussion of this sort, because he has heard more "stuff", both software and hardware, than most any of us amateurs.

The discussion is degenerating into a series of inconclusive anecdotes. If you take the single master tape from a modern studio and from it create both a 33 and a 45, on the same lathe using the same source of vinyl on the same day and then play the two versions on the same turntable with same tonearm and cartridge, the physics say the 45 will sound “better”. In any single instance, for many reasons unrelated to rpm, the result can be otherwise. Period.

Differences that favor the original 33 version over the re-issue 45 version could of course be related simply to the quality level of the respective manufacturing processes.  Those are variables we cannot control for, and the data are worthless for saying that 33 is superior to 45, as a general conclusion. Bill, can you amplify on your assertion that "the faster the speed, the more noise will be generated".  What kind of noise are you talking about, for one thing?  Are there some published data that support your contention?

What is your question? The physics dictates that 45 rpm is superior, but you won’t always hear the difference if the source material is flawed. However 33 should not sound BETTER than 45. Possibly your turntable is having issues at 45 rpm. The auto engine analogy doesn’t help.