Although the notches in the f-holes can be a good general suggestion for bridge placement, they aren't always the best location on every instrument.
Determining a more accurate and often better sounding placement is achieved by determining the MENSUR. The MENSUR is a ratio of neck length to partial body length to determine bridge location.
Use the following instructions to determine the MENSUR of a violin/viola:
1. Measurement 1:
Measure the distance from the end of the nut (closest to the fingerboard) to the edge of the violin top next to the neck.
2. Divide the total of Measurement 1 by two. (13 cm / 2=6.5 cm on most 4/4 violins)
3. Multiply that number by three. (6.5cm x 3= 19.5cm on most 4/4 violins)
4. The resulting measurement (from the edge by the neck, to the center of the bridge foot) is the proper location of the bridge for the violin/viola, thus a 2:3 ratio.
The MENSUR for the Cello the ratio is 7:10 and the Bass is 3:4.A couple of final important notes.
*When moving your bridge to a new location, your soundpost may also need adjusted. Make sure to bring the instrument in to see if your soundpost needs to be tweaked with your new bridge placement.
*If you have any markings on your fingerboard (like tapes for finger placement), these markings will also need to change as a result of a bridge shift and lengthening or shortening the vibrating string length.
Although we strongly recommend having the size checked by a teacher and/or a member of our staff, we realize it isn't always feasible to bring the student to our store for sizing.