My surround speaker wires are already pre-wired in-wall. But they were for 5.1. So, only two pairs are wired from one wall (front) to the other wall (back). Now, for 7.1, I'm looking for ways to add two more pairs.
I am thinking about just tightly attaching the new wires ( 2 pairs ) to an existing one-pair wire and pulling it from one end. Would it work ? What kind of risk am I taking with this method ?