Radiused Top And Back

[Geo]

I'm wondering why the top and back of a "flat-top" acoustic are radiused. Obviously it's simpler to make them completely flat.

It can't be a significant-enough increase in volume... otherwise all guitars would be archtops.

My only guess is it increases strength.

[thegarehanman]

Yup, increased strength would be correct. The tops have a dome shape though, not a continuous radius along the length of the top (like a cylinder).

[fryovanni]

I'm wondering why the top and back of a "flat-top" acoustic are radiused. Obviously it's simpler to make them completely flat.

It can't be a significant-enough increase in volume... otherwise all guitars would be archtops.

My only guess is it increases strength.

It does increase strength, as well as stability. It also changes the voice(most find it preferable). People use different radiuses, some stronger than others. You can use a flat top with no radius, but it will be more prone to distortion and requires stronger bracing(if you use the same thickness top). The radius is an efficient solution. If you could get away with the same bracing and soundboard thickness, a flat top is actually more efficient(but for all the reasons above less effective).

Archtops, Have a much stronger arch, as well as different bridge system(forces acting on the plate are different than with a pinned bridge). They also make use of F holes and thicknessing of the recurve to adjust the responce of the top as well as the back. Different animals.

Peace,Rich

[Geo]

Thanks for the enlightening replies!