[Edgar Aichinger]
Another fact is, that a string has a "sweet
spot" in tension, where
it sounds best. So when stringing an instrument you aim for that by
choosing material and thickness (besides basic sound characteristics
you wouldn't mix, like solid metal vs. gut).
It's always a compromise and often a foul one ;) For purely acoustic
instruments in an ensemble or in a large room, I guess that sheer
loudness can at times become vital; it also often seems preferable to
emphasise treble over bass a bit in order to keep the ensemble's
audible impression from becoming too boomy.
Cheers, Tim