No surprise to me. The specs said 103dB for the Bose S1 Pro.
That‘s simply not enough for a PA system.
Small PA systems like FBT J5a, JBL Eon 206p, HK Nano 300 or Bose L1 all have more than 110dB.
The Bose S1 pro is certainly nice, but too expensive as a mini PA system.