openation

Hello, I just bought a 10" subwoofer for my onkyo Tx-Sr705 and it doesn't work that good. It's a wireless and I know I hook it up right. but it doesn't work Please advice me how to connected so it can work. I connected the transmitter to the subwoofer output but the sound does come out barely. I bought it because i thought it was going to be awesome, I am totally discouraged.