How to Brace a Guitar Back Plate
Bracing the Guitar Backplate
The biggest trick in bracing the Back plate in to get a consistent arch on the back plate. The reason for the arch is two-fold.
The Back Arch Acts To Reflect Sound: First the arch acts as a reflector of the sound waves that are produced by the top plate. As these sound waves reach the back, they set the back to resonate as well. The arch acts like a concave magnifying glass only with sound waves in lieu of light waves. The shape focuses the waves and directs them upward toward the top plate and through the sound hole.
The Back Arch Gives The Guitar Added Strength: Secondly the arch gives the back, and the whole guitar for that matter, greatly increased structural strength from tension that is exerted from the strings. The arch also gives the guitar some “breathing room” for humidity changes.