Double Bass Extension Scales

[Yvarg]

Sorry if this has been covered before, but it didn't show up in the search feature. I was curious about the scale length of E strings extended with C and/or B extensions. I would assume they add about eight or so inches or so to the scale length of the string, but I wanted some official measurements (contemplating building my own extension, because it doesn't look too hard ). Thanks in advance!

[Ludwig]

The length of the extension depends on the normal vibrating length, different for different basses. Add about 6% to that length for every half-tone step. C to E are 4 halftone steps, that means the total vibrating length for C has to be: 1.06 * 1.06 * 1.06 * 1.06 * (vibrating length of E) = 1.262 * E_Length. For a normal 3/4 double bass with scale length of 104 cm that comes to about 131.3 cm, the extension would have to be 27,3 cm long.

[Yvarg]

Ah, so then, using that same equation and converting the answer into inches (crazy Americans XP) a B extension would have to be just about 13 5.5/16" long. Thank you!