size of sound hole

[pickinBob]

Could someone please explain how the size of the sound hole effects the instruments tone and projection? I see lots of different instruments with small holes and some with medium holes and some with large holes? What gives?

[Dolamon]

Supposedly this is part of the Helmholtz equations which were explored in the late 19th century. Smaller sound holes (supposedly) create more of a bass note, the larger the hole, the closer to a balanced or treble sound. This is a really terse explanation and I'm sure someone else here could do better - or correct my assumptions. Now for F holes ... I haven't a clue how that would work.

[pickinBob]

The reason I was curious is that some zoukz lets say, like Steve Smiths have relatively large holes, so do Crumps. But the Freshwaters and the Troubadors have smaller holes.