Volume too low with Shure SM58
I unpacked a Bose S1 Pro today (alongside my L1S/B2/T1) planning to use it at a small gig on wednesday. But I am disappointed with the volume on the microphone (Shure SM58). I have tried different inputs and settings. The guitar sound great and with lots of headroom, but I have to crank the volume almost to maximum to get (to my ears) a reasonable volume from the Shure.
(I have ordered a Sennheiser e945, thinking it was a better mic than the SM58 (which is OK) but I'm getting second thoughts about that. I won't have it before wednesday anyway.)
So, can anyone help with my volume problem? Am I missing something?