Here are some of the speaker setups that can be used:
1. If you want to use a full 7.1 Channel setup, you can use the Front, Center, Surround, and Surround Back connections.
2. If you don't want to use the 7.1 Channel setup with the Surround Back option, you can exclude the surround back channel and just use the rest of the speakers in a 5.1 channel speaker setup.
3. If you want to Bi-Amp your front main speakers (some speakers have separate terminals for the tweeter/midrange and woofer sections). You can use the Main and Surround Back speaker terminals to accomplish this.
In addition to the physical speaker connections, you will also need to use the menu setup options of the receiver to send the correct signal information to the speaker terminals, based on what speaker configuration option you are utilizing.