Must speakers have certain volume to sound convincing ?

Well, Getz's sax and even more Gilberto's voice don't impress me regardless of speakers.
Everyone hears differently or processes what is heard differently? Assuming good hearing, of course.

Besides what Mapman said I also meant internal physical volume of speakers.
Panels sound nothing like real music, as beautiful as they can do. They are for dreamers not for those who want to hear it as it is.
As for horns, it's a different matter.

Right, size does matter.

Stradivarius will sound great in anyone's hands just as great speakers will sound great regardless of what kind of junk they are forced to play by some so-called audiophiles and giftless musicians.
It's quite telling that no-one so far asked me why I think panels don't sound real. In any case, that notion of mine was not the main line.
It also appears at the moment that what I said about proccessing of perceptions may be an incomprehensible remark. No matter, let's continue with usual bullsh-t.

Right. We live for the chase and thrive on arguments.
Never played Stradivarius but once I did play a very high level custom classical guitar. It sounded spectacular, and my skill as a guitar player is rudimentary. True, violin is a more difficult instrument than guitar or piano, generally speaking, but I am quite certain that this makes no difference. I heard excellent violins played by lousy musicians.