Official Luthiers Forum!

What's the minimum body depth you will use at the neck?
Richard

3 1/4 at the neck

I have a tenor right now that is coming out right about 2 1/4" at the neck....

Otherwise, 3 1/8" on the Oakie

Thanks

John

Thinnest acoustic guitar I've seen are photos of is a 1916 Maurer (Larson) with a box depth of 2-1/4" at it's thickest point. This was a "standard size" instrument which I would guess to be around 14". Larson instruments were heavily arched though.
Thinnest I would make a 15" would probably be around 3". but I use a pretty deep dish too...

I'm curious to hear reasoning behind people's numbers. Do you need a thick enough heel block to give better torque hold the neck back? Is it an acoustic decision, or just how the instrument feels? And, is it like a Manzer taper kind of deal? When you make the heel shallow, do you make the other end deeper to maintain an approximate volume? Or do you like to keep a certain ratio from one end to the other, and again why? Sound, feel, look?

Mike

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Mike Lindstrom

I think alot of varibles come into play when changeing the volume in the box by making it shallower at the neck.I do think it can have an effect on projection of sound.Shape and size changes have a large effect on that i have found in my builds.

Personally, I saw a whole lot of hype around the super-deep boxes... but when I built the Ditson GC (Martin Size 11, 13 1/2" across the lower bout) -- I basically went with the print on the 1st one. It worked pretty well -- plenty of bass and otherwise really nice balance, so I stuck with it.

I think Al has pointed out that there a whole bunch of relationships tangled up together with Box size, box depth, top and back compliance, soundhole, etc..... If you make a fairly lightly built top and back, the body resonance will be sufficiently low... even on a "Standard" depth box.

Thanks

John

My thinnest is a Cordoba FCWE (spruce/maple nylon 12 fret). Depth tapers 2.5" to 2.75", body length 19, bout widths 10.5, 9.25, 14.5, soundhole 3.5, scale length 25.5. It's a great example that size != volume. The thin box definitely affects the tone, it has a sharp "boing" sound to it, although you can get a more regular classical sound depending on where/how you pluck the strings. I love it. I would probably go with a deeper body if I was going to build a similar steel string though, to offset the naturally brighter twangy sound of steel. Maybe add .5" or so.