pioneer elite vsx-90 subwoofer troubleshooting

Hello, All. I just moved, and I am setting up my home theater system in the new place. All works well, except I can't get sound out of my subwoofer. I've done a bit of troubleshooting, and gone into the receiver's system setup menu, and the subwoofer options aren't there as described in the manual. they are supposed to be at the bottom of a list of manual speaker setup options, and they just aren't there. I assume that some other setting has inadvertently disabled this? Any thoughts are welcome. And apologies if I have posted in the wrong place. Thank you.