You sure can. The SubPac makes a great addition to the experience of watching a movie!
The S2 can be used in your home theater setup. It can receive a line in signal from the discrete LFE channel or use a LT RT down mixed stereo signal and pass the low end to your body. If your surround system has a set of 6 line outs connect the one labeled sub or LFE to the appropriate adapter to feed the S2. Do not connect the S2 to a speaker output from the amp. This will be too much voltage and may damage the unit. If your receiver does not have discrete connections look for a stereo line out or headphone out. These usually will contain a LT RT mix down of the surround sound along with plenty of bass to feel.