I have a a Phillips 55PFL5706/F7 LCD TV. I bought a cheap surround sound system by RCA, with just a sub and some speakers. The sound is processing too quickly and is ahead of the video. The manual for this TV is pretty lousy, anything I can do to fix this? I am watching digital cable in HD. Cable from the wall, to the cable box. HDMI cable from cable box to TV. Red & White cable connected from RCA sub to cable box.