This will be interesting... I just started playing bass in a band (the guitarist is the bass player in my main band and the drummer plays in both).
He tunes his guitar down to drop C#. Their last bass player tuned a 4 string Jazz bass down to C#. I have a 5 string, so obviously I don’t need to tune my bass down. But the way the songs are written they use a lot of the open C# bottom string, and I have a low B. Made playing the riffs awkward.
So I tuned my bass UP a step (C#-F#-B-E-A). That works great, but my 40-120 set of strings are really stiff now! And I had to tighten the truss rod quite a bit.
So I’m going to try a D’Addario EXL180 “Extra Super alight” set for the top 4 strings - 35-95, and put like a .110 or .105 on the bottom.