Some bass strings are offered in "solo gauge" or "solo tuning" as an option. These strings vary only slightly from "orchestra gauge", or "orchestra tuning" which is the normal string for double bass.

Upright bass tuning is normally G-D-A-E (high to low), while "solo tuning" is one full step higher: A-E-B-F# (high to low), so solo tuning strings are gauged for that slightly higher pitch.

Why would someone choose a solo tuning string set?? The first reason is obvious-- if they are a solo performance artist. But the more common reason we find is for customers to get a string that is slightly lower tension than orchestra gauge -- they'll install a solo set and tune it down to "normal" G-D-A-E tuning.

Want to get a rough idea as to the difference in tension, at least in terms of your current strings?? Tune your current strings down one full step, to F-C-G-D (high to low)