PS3 and Surround sound problem?

You will need to set your PS3 to output the audio via the optical cable. Most home theater in a box only have one optical audio input if provided. What I would recommen is set your PS3 to output via the HDMI cable and then connect it to the tv, then connect an optical audio cable from the tv to your home theater in a box. This will also provide you sound for the tv program, keep in mind that only those tv program with the Dolby Digital Logo will have surround sound information. Hope this will help you out.