Body volume

[Malibu]

A theoretical question only...
How much effect does body volume (ie: air space inside the body) have on the tonal qualities of a guitar?
For example, a drum with more volume will have a deeper note than one of less volume given the same construction materials, etc...
Any ideas?

[kiwigeo]

Malibu,

GALs big red books have lots of articles on the subject of instrument acoustics and what controls same.

My knowledge of the science of it all is limited but I do know that body size and shape of a sound chamber and diameter of soundhole will all effect resonance of the instrument....all to do with something called the Helmholtz frequency. Thickness of top will also affect the helmholtz frequency.

[Malibu]

Thanks, I've done a bit of browsing on helmholtz resonators and the science behind guitar acoustics in general. It can all be boiled down to a collection of maths formulas and proven on paper (not that I'm a mathmatician by any stretch) and it's fascinating to see how a guitar works.
From what I can gather, everything you said makes a big difference to the final result; even down to the shape and position of the soundhole on the soundboard.
Being that it's not an exact science, I couldn't find anything anywhere to indicate volume vrs tonal quality of the guitar.
Here's an interesting site on it all anyway (plus a few other instruments too) :)

http://www.phys.unsw.edu.au/music/guitar/