The Russound SRM2.1 Speaker Relay Module is a two-way speaker switch that allows two amplifiers to share the same pair of speakers with the switching done by a 12 Volt (12V) DC trigger. This allows you to share speakers in situations where both amplifiers are permanently on (ie cannot be switched by audio sensing as with the Russound AB3.2) or to share them with specific Russound systems such as the Russound MCA-C5.
Use to interface the Russound MCA-C5 with home cinema
It is possible to do this by using the SRM2.1 Speaker Relay Module in the room and connecting it between the MCA-C5 output and the speakers, ie speaker cable connections. The local input, eg Home Cinema AV receiver, is plugged into the speaker sockets on the front. The SRM2.1 also must be connected (from the rear) to the MCA-C5 12V trigger out for that zone. It will then give automatic A/B switching, normally allowing you to play the local source but switching to multi-room whenever the zone is powered up on the keypad. (See figure 2 in instruction manual)
Use to switch between two amplifiers
When one of the amplifiers has a 12V trigger out, eg a Marantz SR6006 AV receiver or a Marantz Power amp, you can use that to switch between the two. The amp with the 12V trigger would be the permanent rear connection on the SRM2.1. The amp without the 12V trigger would become the input on the front of the SRM2.1 using banana plugs. When working the front connected amp will play by default, and the rear connected 12V amp will over-ride it when it is turned on. When turned off the audio will return to the original amp.
When neither amp has a 12V trigger you can operate the SRM2.1 by using a simple wall switch (latching type eg light switch) and a plug-top 12VDC 100mA supply.