View RSS Feed

Montana Lutherie

Mandolin Bridges

Rate this Entry
I just saw this blog post we did- it's been a year (!) but the info is always timely.

Any of the bridge issues below will rob your instrument of tone and volume and are responsible for more players going on a new string brand or gauge hunt because their instrument just doesn’t sound like it used to.

I know I’ve posted on this topic a few times before, however recently Bruce has gotten quite a few instruments in for miscellaneous work and noticed almost all had bridge issues: poor fit, leaning towards the fingerboard, some bases flipped bass for treble, and messed up saddle slots. It doesn’t matter what kind of bridge you use or prefer, if they aren’t fit properly to the soundboard or any of the other issues listed above, they’re all the same: Worthless for all but a string holder.

Bruce’s Take. The bridge is responsible for efficiently transferring vibration from the strings to the soundboard and on a mandolin has a footprint of about 1.4 square inches plus or minus some depending on the builder. Now picture the bridge leaning towards the fingerboard with only the bottom edge of the base making contact with the top of the instrument. This is usually due to a recent string change pulling the top of the bridge saddle as the string are brought to pitch. The footprint has been reduced to less than .5! Not much contact there to carry anything from the strings to the soundboard. The bridge should be sitting perpendicular to the top and not looking like it wouldn’t take much to push it over. Check out on our site for the fix.

Another issue that reduces the footprint intended by the builder is a poor fit. Fitting a base to an arched top instrument is tricky if you’ve never done it. The base should sit seamlessly on the top and not have a convex shape across the width of the foot or gaps. If you hold your instrument up with the peghead pointed towards a light and look closely at the bottom edge of the bridge on the tailpiece side you shouldn’t see any light passing under the bridge base where it meets the top or visible gaps. If that doesn’t work for you try pushing a piece of notepaper under the bridge base from all angles. If it slips between the base and instrument at all, it’s time to visit your local luthier. Another way to check the fit is next time you have all the strings off take a look at the finish where the bridge sits. Most will have a slight imprint in the finish or a slightly different color. Is it the same size as your bridge base?

One more. Swapping the bass and treble ends of the bridge base is pretty easy to do, especially if you don’t have mark on the bridge base indicating which is which. When we install a bridge here we mark the bottom of the base on the treble side with a T written in pencil. Check it out next time you do a string change.

As long as we’re on bridges and you’re checking your fit, take a look at your saddle string slots. The slots should be of equal depth and should have a consistent angle pointed down towards the tailpiece and not an inverted V which can cause a string or strings to sound fuzzy. A good luthier can solve this issue in minutes by dressing the slots.

As always, give Bruce a call if you have questions. We love to help players, and their instruments, sound the best they can.
https://www.montanalutherie.com/contact/

Click image for larger version. 

Name:	tradbrgmando.jpeg 
Views:	9 
Size:	22.7 KB 
ID:	178246

Submit "Mandolin Bridges" to Facebook Submit "Mandolin Bridges" to Twitter Submit "Mandolin Bridges" to MySpace Submit "Mandolin Bridges" to Yahoo Submit "Mandolin Bridges" to Google Submit "Mandolin Bridges" to StumbleUpon Submit "Mandolin Bridges" to del.icio.us Submit "Mandolin Bridges" to Digg