Amp play a low volumes?

My experience is that systems ( primarily speakers ) that tend toward warmth sound better at low volumes. This is probably due to how our ears work and perceive tonal balance at different volume levels. This is also why "mid-fi" gear comes with a "loudness" control.

I agree that very low powered amps ( primarily SET's ) or high bias, hot running SS amps will sound best at low listening levels. Sean
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I think opposite about speaker's efficiency. Lower efficiency speakers will sound more quiet at the same volume levels than higher.

Why music sounds thinner and less lifelike at low volumes is a phenomenon called the "Fletcher-Munson Effect". This is when the ear is more sensitive to midrange sounds at low volumes. The "Loudness" button on receivers is designed to compensate for this by equalizing the response curve according to the "Fletcher-Munson Response Curve" which raises the amplitude of the highs and lows at a rate specified in a published,standardized format. This is also why, in the old days, you would see graphic equalizers with all the sliders arranged like a "smiley face". If a speaker sounds flat and neutral at very low volumes, then you can bet it will be boomy/sizzly when listening at louder levels. Conversely, a speaker that is very neutral will sound rolled off at both ends when listening at very low volumes. This is due to the "Fletcher-Munson Effect" as described above. Sean got it right.

This has been an interesting thread-- thanks Jcd. I think I "re-learned" some things I had forgotten, re Sean and Twl. But that still doesn't explain why my (past Vand. 3As) sounded good at low Vol., but Vand. 5s don't.

Sean may have hit it though, ie warm sounding speakers (3As) may sound better than the more neutral 5s-- that sort of makes sense to me. And as the 5s continue to breakin, they ARE sounding better at low vols.-- and getting warmer. A big contributor to this (warmth) was also a change from Acme silver outlet to copper FIM. Cheers. Craig

Twl, it's true I've grabbed a lot from your great answer
THANKS!