How about replacing batteries with traditional speakers?

Single power supply can be changed to 12V battery power supply! Remove two wires from the output of the transformer and connect them to the positive and negative terminals of the 12V battery. Pay attention to distinguish between positive and negative poles. The dual power supply can also be replaced. Remove the three output wires of the transformer, connect the positive and negative electrodes of the battery to the two connectors powered by the dual power supply, and ignore the negative connector. Disconnect three input audio wires (R.L. ground wires) with three capacitors of 100uf and connect them to the audio input terminal! It's just that the voice is a little low. If it is turned up, there will be communication. However, the stereo with subwoofer costs a lot of electricity, so turning it down can save electricity!