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Hi everybody! I'm in the process of designing a new guitar, and am grappling with a couple of design issues and thought I would appeal to the collective wisdom out there. At this point, I'm looking at a body size of 20 3/8" long, top bout 10 3/4", bottom bout 15 1/2", 3 1/2" deep at the neck block and 4 1/4" deep at the tail block. Neck joins the body at the 14th fret. It will have a Venetian cutaway and will be geared towards the fingerstyle player. My first concern is fret scale; 25" or 25 1/2". I am aware of the obvious issues of fret distance and string tension, however, I am uncertain about the effect this will have on the tone of the instrument. My second concern is calculating the optimum size of the sound hole. I am considering a port on the side directing sound towards the player. What are the pros and cons and how does one calculate the best size and location? I'm still drawing up plans, so any suggestions and/or comments would be greatly appreciated.

Thanks

If you want to understand a phenomenon that you don't really understand at first sight, try to exagerate it in both ways, and think.

Example: scale lenght affect on tone.
Keeping the same frequency, with the same string, what the difference if you tune it on a 20'' scale, and on a 30'' scale.

20''-> The string will be really, really floppy. Not a long of sound, not a lot of harmonics, probably only the fundamental.
30''-> The string will be very tight. a very percussive attack, a lot of high harmonics (really bright sound)

That said, you can deduce the effect of the scale lenght.

What happen if you have no soundhole, or a really small one?
What happen if you have a reaaally large soundhole?

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Francis Richer, Montréal
Les Guitares F&M Guitars