Hello! I have searched the archive but can't find what I am looking for. Similar question but mine has a little extra that I can't figure out.
I want to distribute the sound to some speakers at various location in the house and have control of the volume locally. Using Impedance Matching Volume Control (IMVC) seems to be the solution. However, If I want to add an A/B switch in one location so that I can use the speakers in that location for the central source or the local source, it changes the impedance of the central circuits.
I've been told I need to use a speaker selector box (and leave them all ON if I want) but I am not sure I understand.
Please see my installation here:It shows want I want to do. There are some questions too. All the help is welcome.