Must speakers have certain volume to sound convincing ?

I have found that how loud a system needs to be played to be satisfying is not just a matter of the type of speaker or particular models of speakers.  The nature of the amplifier is as important.  I have been at demonstrations where people who are new to tube amplifiers are amazed at how "loud" they sound even though they have a much lower wattage rating than the solid state that it is being compared to.  Some people even talk as if a "tube watt" delivers more volume than a solid state watt.  I don't think so.  I think that, at any given volume a good tube amp sounds more satisfying and engaging that one just thinks it is playing louder.  I don't find better solid state amps to be grainy or harsh or thin or bright (the common accusations leveled at solid state), what I find is that most sound a little lifeless and I tend to lose interest and concentration quicker when I listen to solid state.  In fact, those negative attributes are, to me, much more common to high-powered tube amps than solid state ones.

I have found that, as I have improved my system over the years, I tend to play it at lower and lower volume levels; I don't look at ability to achieve higher volume levels as a major objective.  As to "realistic" sound, I again don't think high volume capability is paramount.  For classical music, even if one could achieve comparable peak volume levels, one would never play the system that way because the quieter parts of the music would be WAY too loud (recordings do not have realistic dynamic range).  For jazz and smaller ensemble music, I actually prefer listening at levels below that of live venues.  I don't really want to reproduce the live experience of a rock concert at home either; that experience is really not about the sound (if my system ever sounded as bad as that of a live concert, I would junk it).