Soundhole bracing

[NeilG495]

Hi, have mainly followed the Cumpiano design with my past builds but would like to try something different, so looking to a Martin OM OR 000 design. Just wondered what the current thinking was on soundhole brace thickness, shape and placing with regards structural stability and possibly tone. I notice Martin use 3 thin flat braces around the soundhole, which look a little flimsy compared to the Cumpiano 1/4” x 1/4” stock. Any advice/guidance on the subject much appreciated.

[John Parchem]

Hi Neil,

Welcome to the group.

Bracing for a guitar is a system and any give brace does not stand alone. So if you are making a Martin style top feel free to use their brace heights. When I make an x braced Martin style guitar I use the thin braces. When I make a classical guitar I use a 2mm thick sound hole patch. When I make my falcate guitars my sound hole braces are about 1/4" x 1/4" and they are carefully tied in to the other braces; I need them for structure reasons as well has stiffening the sound hole.

[NeilG495]

Hi Neil,

Welcome to the group.

Bracing for a guitar is a system and any give brace does not stand alone. So if you are making a Martin style top feel free to use their brace heights. When I make an x braced Martin style guitar I use the thin braces. When I make a classical guitar I use a 2mm thick sound hole patch. When I make my falcate guitars my sound hole braces are about 1/4" x 1/4" and they are carefully tied in to the other braces; I need them for structure reasons as well has stiffening the sound hole.

Hi John, many thanks for the welcome and the info it’s very much appreciated. I’ll use the Martin thin soundhole braces then as I’d like to get as close to 000 sound as possible. I intend to use 5/16” thick x 1/2” high for the X brace and 1/4” thick stock for the lower face and finger braces but can’t find any info on the finished height for these. Could I ask what finished brace heights you aim for when building a Martin style guitar?

[Dave Bagwill]

I use this Lowden system. 1/4" braces, thru the upper transverse and then butting into the X.

[NeilG495]

Great photo Dave, thank you. I’ve seen this bracing pattern before but it seems as far from the little flat Martin braces as you could get. Could I ask the thinking behind it? Have old Martin’s had issues with distortion around the soundhole?

[Dave Bagwill]

Maybe some of the repair guys here on the forum can answer to the Martin distortion issue - I'm not aware of any problems, but I do notice quite a number of 'boutique' builders do go to a stronger assembly around the hole. Al Carruth has a good video on it that I cannot locate again.

George Lowden, in an interview I watched, did say that he feels the bracing above the X must be 'very tight', so he developed that A-frame system to counter distortion, and to provide support and help prevent headblock rotation. I like it, without any 'proof' so to speak, because it does feel like I am tying the whole thing together up there.
$.02

[NeilG495]

Thanks again Dave, I need to give this some thought before I commit to this next build.