Strings 101 - String Gauges
The gauge is a measurement of the average string diameter. Many guitarist buy their strings by the gauge. However, the gauge only tells part of the story about at string. Other parameters such as alloy, silks, nylons, and wrapping are just as much a critical factor. In the very early days of guitar, towards the later part of the nineteenth century, gauge did not receive the attention as it does today. There is not much documentation about gauging from the early years, but most historians believe the guitar gauges were derived from the same gauges used on the violin.
String gauge plays a factor in the frequency, playability, volume, tone and strength of a string. In general, heavier gauge strings will be louder and fuller sounding than a thinner string. Heavier gauge strings tend to work better with acoustic and archtop guitars as they have more mass per unit length. This additional string mass allows for better energy transfer between the string-to-bridge-to-top configuration. Thinner gauge strings will not be louder as their mass per unit length is small, but will give considerable ease in playability for bending and pressing against the frets. Many of today's electric guitars come with highly sensitive pickups that enable guitarist to get the desired volume they need from a thin string.
Bass guitar string sets do not typically offer as many choices in string gauges like standard guitar sets. In addition, their gauge differences are less incremental than standard guitar sets. Heavier bass strings have a much fuller sound and are more responsive to thumbing. Thinner gauge strings will result in a thinner sounding bass with less tonal depth. Some players like the thinner gauges for a brighter sounding bass, and ease of certain string popping techniques.