A compensated bridge is designed to 'compensate' for the fact that a string with a lower pitch needs to be slightly longer in order to note true. The effect of a 'non-compensated' bridge is most pronounced high up the neck where the tolerances are smaller. Often you find the third and second strings noting untrue.

Notice how a the saddle on an acoustic guitar slants towards the bass side. This allows the strings to be longer as they get lower in pitch. An electric guitar can be compensated very accurately as many bridges have individual saddle pieces for each string.

Not so for banjo... The various compensated banjo bridges attempt to deal with this in different ways.

The first (as I recall) was the Shubb bridge which showed up in the late 70's. Rick Shubb produced a bridge that used a sort of stair step design that had the third string at the longest point, stepped forward for the fourth and second strings, and stepped forward once more for the first and fifth. Something like this:

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Unfortunately, the bridges tended to be unstable and broke easily. They were also so bulky that the tone transfer was not very good. But, it *did* solve the problem it set out to solve - intonation up the neck was greatly improved.

The Moon bridge tries to solve this by building a curved bridge from a solid piece of wood. I've never used this bridge and don't know if it is carved or bent. Perhaps someone on the list knows.

The Stelling bridge settled on compensating by the depth of the string notches. The third string notch is not cut as deeply, thereby making the string slightly longer. Likewise, the first and fifth strings are cut more deeply.

I'm not sure how the Snuffy Smith bridge compensates, if at all.

The Hot Spot bridge notches the area of the bridge back where the third string attaches, creating a longer string.

**** Disclaimer I am a dealer for the Hot Spot. =) *****

Any good, after market bridge will improve the tone of any banjo. Which one does the best on your banjo is a matter of taste. If you aren't playing much way up the neck, you may not notice much difference with a compensated bridge.

Most of us banjo pickers will eventually try - and buy - them all.

Thanks to John Lawless for this info!