Template:Audio System Noise and the S1 Pro
This is an excerpt from Audio System Noise. Please follow the link to read more general concepts and solutions.
The S1 Pro System is different from the L1 and F1 Model 812 Flexible Array Loudspeaker families of products because you can remove the AC power plug and run on the internal batteries.
Removing the AC Power isolates the AC Line Noise and Ground Loops.
If you have a hum or buzz or excessive hiss try unplugging the AC power.
Related conversation:
Feedback hum on channel 3 in the Bose Portable PA Community