Help needed for Legacy Dual 12” Subwoofer

Now that my son is off to College in California, I’m trying to fill this big void by setting up my home theater.

i purchased a classic Legacy Dual 12” subwoofer over 20 years ago and after few moves, I’d since lost my owner’s manual. On the input terminal, there sits two sets of binding post (4 total) and two toggle switches directly above. Last time I used this was as dedicated center channel sub but I can’t remember the purpose of these switches.

Much appreciated if anyone can share me some information. Link below is the photo to the binding posts and switches. 

https://www.usaudiomart.com/view_userimages.php?user_id=149477&image_id=26288

Thanks Regard
Mosler666