A3 bracing

Here is a quick photo of the internals of a mahogany model A3 14 fret long scale tenor i'm assembling today showing my current tenor bracing style. I use a wide 1mm thick Mediterranean cypress cross brace which runs across the widest part of the lower bout with 3 spruce fan braces (approx 3mm x 5mm). The cross brace is thinned at the edges and helps the top retain the arch carved into the solera. The fan braces are notched where they pass over the cypress brace. They are scalloped on the end near the sound hole and tapered on the end near the tailblock. The top is approx. 1.75 mm thick overall. The sound hole is reinforced with two cross grain spruce patches about 1mm thick. You can see a small piece of wood and screw used to hold the body down on the solera during assembly. It's removed after the back is attached.

After the bridge is glued and before i lacquer the instrument, I'll string it up and give the top a once over with a sanding block thin enough to allow me to work under the strings below the soundhole, and around the periphery of the lower bout. The goal is to optimize the tone and responsiveness of the instrument. Small adjustments can make a big difference to the sound.

The back is braced with 3 spruce cross braces and a 1 mm thick cross grain spruce patch to reinforce the center seam. The cross braces are tapered in profile and their ends are scalloped. The goal is to produce a strong and light structure which is compliant around the edges.