Try reconfiguring your current slave as master and vice-versa. Re-wire the cables and comms accordingly and see whether the dormant speaker is working...

Oh and before you do that, make sure your current master-to-slave SPDIF is going into the correct connector on the slave.

Last edited by Gianni; 2020-02-09 18:27. Reason: Thought about the SPDIF route.
In the spirit of Spinaltap, I would like to confirm that I am not involved in the corrupt theft of a global sport.