F-Holes vs. No F-Holes

Wow - I dig these scientific posts 8)

Sorry if I don't get quite as technical; I slept thru high school and never went to college :wink:

So - Noteboat wrote: "And that boils down to what the soundholes DO... by introducing an opening to the cavity, they allow Helmholz resonance. In the case of F holes, they also interrupt the structural connection between the center of the top and the adjacent sides, allowing the center of the top to 'float'. Since those are the two big differences, one (or both) must be responsible for the feedback."

Yes, I was always under the assumption that 'f-holes' weaken the structural integrity of the top, allowing it to vibrate more freely.
And I suppose that I always thought it would vibrate more from the strings - as in the string/bridge/body coupling,
thus inducing sympathetic vibrational frequencies with the strings = feedback (?)

The Helmholtz thing is interesting though.
Using a piece of paper as a model for a guitar top - left unmolested, and blowing across it, it wouldn't vibrate all that much.
Cutting two slices into it and blowing acoss it creates wild vibrations.
This is caused both from a weakening of the paper, and from the introduction of moving air.
(Is that really akin to Helmholtz resonance though?)

So, is H resonance that prominant in this case (ie. guitar top w/F-holes?).
I'm not sure that I understand it it all that well.... it seems to rely heavily on the system having a 'neck' to supply the proper presures for it to work efficiently.
And in so doing, doesn't Helmholtz create a 'sound' - as in the usual example of blowing over a bottle opening?
So, what I'm asking is.... Wouldn't the Helmholtz factor in a soundcavity/f-hole make noise/tone thru the f-hole?
And is the f-hole a proper enough 'neck' for it to work that way?

At any rate - The question is: What would an F-hole do to the tone of a Carvin 550?
It seems to me that it does not have a 'real' hollowbody type top (which is thin - as opposed to the Carvin's thick one,
carved from a thick chunk of wood).... So, that would, in effect, alter the acoustic resonance properties of the top.
Enough to cancel the factors that produce feedback in a typical hollowbody system?
I guess the question is - Why do they put f-holes in hollowbody/electric guitars if they dont really alter the overall tone that much, and pretty much do nothing more than produce unwanted feedback?

Ken