Down Firing Subwoofer Can I Use A Powered Subwoofer?

Can i use a powered subwoofer? - down firing subwoofer

I have a Panasonic SA-ht650 home theater system model. The subwoofer that came with it stinks. I was thinking about buying a subwoofer for that. I have the problem that I meet no sub on the back of my receiver. I have a room for a segment that a speaker cable used. Deputy I now not on and there is a speaker cable that from the sub to the receiver. There are ways I have. I have tried to buy this subwoofer. Yamaha YST-SW216 Subwoofer 100W Front. The I ask because once 2 people said it would with the front L & R speaker terminals work and then run to the front and front speakers from left to right under U-boat. Another person told me that you can not use a subwoofer with this theater, because it was a low-end model. If the model # sa-ht650 the second link on Google gives you the full manual. Thank you for your help!