What Soundhole Size?

[ozziebluesman]

G'day all,

I'm building two concert size guitars as a batch. One will be to the Scott Antes concert plan, 25.5 inch scale with the bracing lightened up considerabily. It's soundhole size is 95mm. The other is a 0-18 Martin concert size guitar copy with 24.9 inch scale and light bracing. Bob Connor has kindly sent me a pic of an original Martin 0-171937 top as a guide to work off. The body is 345 mm LB, 250 UB, 460 L, tail thickness 105 and nech block 85 mm. Top is sitka 2.75 mm thick and back and side Indian Rosewood just under 2mm.

My question is dose the size of the soundhole affect the volume of an instrument? I have been told on good authority that a larger soundhole will boost the treble.

All thoughts greatly received. I'm on hoildays all next week and would like to start on the rosette and soundhole so I have to make a decision on a size.

Cheers

Alan

[DarwinStrings]

Hi Alen here is some reading for you mate on the soundhole size question. http://hal9000.ps.uci.edu/Weber%20H90%2 ... 0Paper.pdf

Jim

[ozziebluesman]

Thanks Jim,

Some interesting findings in that article!

I often wondered that a sound port would have to affect the overall volume of an instrument too!!

Think I will go with the size Martin use! Proven and tested!

Cheers

Alan

[kiwigeo]

Interesting article in last GAL journal..they did some testing on ported guitars. I havent read the entire article but it would seem that the consensus of the tsesting panel was that it didnt make a whole lot of difference to the sound of the guitar.

Interesting stuff.

[DarwinStrings]

You can do a quick experiment yourself to hear the difference in hole sizes, well at least in reducing the hole size of a existing instrument. Just take a piece of wood, cardboard, anything and cover the sound hole bit at a time as you pluck the strings. You will hear the sound change.

Jim