How do you intonate an acoustic bridge?

[Tommygunn]

The title says it all, I've never learned.


Thanks guys

[Benjamin Strange]

You can shape it a little bit, but that's about all. Having a low action can help. If it's drastically out, there's not really anything to be done - unless you want to remove the entire bridge and re-place it.

[Rickett Customs]

Or unless you're a bit "handy" with wood, you can route the slot forward or backward, but if you want it to look good, gonna need a to cut a small "filler" strip of the species of wood or in some cases plastic. But that's only in the case that the move isn't too drastic.

[202dy]

Another approach, for those with very good skills and machinery, or those with large bank accounts who are wiling to have a pro do it right the first time:

The bridge can modified to accept a wider saddle. Think Ovation. Once acceptable string height and relief achieved, the intonation of each string is measured to give an idea of wide the new saddle will have to be. Or, the existing saddle slot can be filled with a plastic filler saddle that is trimmed flush with the top of the bridge. Leave a space on one or both sides so that it can be easily removed. Then small cheater saddles are employed to determine saddle placement. The saddles can be drill bits, strings, or other rod such as pieces of coat hanger. The cheaters are rolled into place until the intonation is correct. Measurements are taken and laid out on the bridge.

Now the hard part comes. The new saddle slot is routed into the bridge, taking advantage of the original saddle bias. The new saddle may be a 1/4" or as much as 1/2" wide. Once the slot is completed, the new saddle is constructed out of a suitable material. Individual saddle peaks are machined into the new master saddle. Through trial and error the peaks are refined until intonation is correct.

That is, until the weather changes.

[walterw]

on any acoustic that's worth a damn, the bridge is pretty much set in the right place already. bad intonation is a result of other factors being off, like old, dead strings or too-high action.

get the set-up dialed in and the intonation will line itself up again.