might sound like a daft question, but on the amplifiers I've had, they have had 4 places to connect the cable for the sub.

two just normal + and -, and then the "bridged" + and -

what is the purpose of the bridged connectors? Which two should I be using?

Am I meant to use the bridged ones if I'm powering just the one sub, then all 4 if I want to use two?

Cheers

Keir