Hissing sound from Bose L1 pro 16

Portable PA
1

Does anyone know to overcome/solve the hissing sound from Bose L1 pro 16 speakers?

My setup as follows;

Microphone/ Yamaha keyboard/Bluetooth adapter/Smart TV are inputting to Allen & Heath ZED-12FX 12-Channel Mixer and outputting from mixer to 2 Bose L1 pro 16 speakers. 
Thanks in advance!

 

 

2

Is this a noise floor issue?

3

It came from speakers when we stop play music.

4

Hey aipham66!

I recommend turning each of the channel faders down individually on the ZED mixer to see whether this is being caused by one specific audio source.

If so, does the hissing continue if you turn down the input volumes on the L1 Pro16 system?

Note - professional PA systems inherently have a higher noise floor when compared to other home electronics.