What is four-channel lock used for?
It is used when you plan on connecting wireless rear speakers (7.1-channel). All four channels will maintain a locked volume level with respect to each other, and this makes setting up the gain for the rear and surround speakers easier, as the volume adjusts together. By turning it on, any other Rocketboost receiver that is part of the network will not be able to receive the rear-channel or surround-channel audio playing to these speakers.
