Bridge Mass

[pmadison]

What is the optimum bridge? A lot of mass? Not much mass? A violin bridge is light in structure as opposed to that of a mandolin. How about one made from carbon fiber, or metal?

Is there a 'fact' that I have missed? I build some of my bridges, and now I want to experiment without going through all the pitfalls of discovery and error. Any helop?

Thanx

[sunburst]

When a bridge is installed on a mandolin it becomes part of the bridge/top system. The mass of that system affects the sound. The mass of the bridge itself is only part of that system, but it does have an effect.
For any mandolin there is an optimal bridge mass, and that mass is subjective. Some like a louder more percussive sound, and a lighter bridge may help with that. Some like a smoother more sustaining sound and a heavier bridge may help that. Part of the characteristic sound of different types of mandolins is resultant from the mass of the bridge, and large deviations from that typical mass can take you away from the characteristic sound.

As for other materials, damping properties make a difference as well as mass, so it comes down to whether or not a different material sounds good to the individual in question.

[Lefty Luthier]

I am certain that every luthier has their own theory. Mine is that proper bridge foot to soundboard contact and saddle rigidity are the most important characteristics. I don't think metal is a good idea primarily because the coefficient of thermal expansion is too different from wood. IE. temperature changes would drastically alter tuning. On the other hand, I see nothing wrong with a saddle made from graphite composite though again I don't think it would make a good bridge base. I sometimes use a bone saddle insert when constructing rosewood bridges and have been playing around with graphite but to date have not come to any conclisions.

[Paul Hostetter]

Very well put. I'd simply add that talking about it on the internet is a distant second to just trying some different kinds of bridges and seeing what works.