Speaker Connectors Explained .
To connect each wire, make sure that you’ve stripped the ends so the bare wire is showing (a few minutes with a sharp knife and a cutting board will do the job – although please, please, please be careful with your fingers while you’re removing the insulation, and although you probably don’t need to be reminded of it, do NOT do this with anything plugged in). The positive wire needs to be connected to the positive terminal (red) and the negative to the negative (black). What you’ll be doing is essentially unscrewing the connectors on the receiver to reveal a small hole, which you’ll then insert the bare wire into before screwing it back down.
And that’s it! These are the simplest connectors to deal with, as they are usually clearly labelled, and while it’s a little bit fiddly to insert the wire, the actual process should be very straightforward.