connecting outside speakers to L/R Line Out


Mar 15, 2015
Hi, I need to connect two outside speakers to an Onkyo TX-SR333 5.1 receiver. All my (5+1) indoors speakers are connected directly using speaker/subwoofer wire.
Now I have four more cables coming into the house. Based on their lables, two for each of the two outside speakers. I had hoped to connect these wires to the red and white Line Out connectors on the receiver (which apparently can handle two zones). The speaker wire banana plug connectors I used to connect the speaker wire to the indoor speakers are two big and do not fit in the L/R red/white plugs. So, what type of adapter do I need to connect the outside speaker cables to the L/R out plugs? Thanks!