toneAC v1.2 - Twice the volume, higher quality, higher frequency, etc.

Hi

I want to connect two speakers (left speaker & right speaker), I know the specs says connect pin9 & 10 to speaker wires. The speakers will not play at the same time, only one or the other. I am using UNO, how to achieve 2 speakers connection?

FYI, I know I can make a control switch circuit to switch between left and right speakers. But I'd rather not do that if there is a way to connect two separate speakers. Again only one speaker will be active at one time.

Thanks in advance