A:AnswerThe sending and receipt units are supposed to be “paired”.
The manufacturer would have to tell you how many different frequencies that they use in their production along with if there are any codes on the units that indicate what they are.
You could always just try to use two receivers with one sending unit.
A:AnswerHow are the rear speakers connected to the sub? Are there typical speaker outs like with your main amplifier
or are the wires built into the cabinet?
If there are speaker output jacks as if it were an amplifier - there should be no problem.
