Additional speakers for 4yr old system
I have a 4 yr old Sonos system. It includes two One SLs,. two Connects and two Connect amps. The amps are for non-Sonos speakers. I'm running S1 OS . I was going to buy additional One SLs from e-bay, but from what I've read, it seems I can't add another 4 yr.old One SL. Is that true? Could I add a non-SL One? Because my system is 4 yrs. old, I didn't want to cause any compatibilty issues by upgrading to the S2 OS. What should I use for the additional speakers?
