You should be able to use both sets of cables. Try running the audio out of the cable box into your speakers via RCA. If the cable remote is only controlling the TV volume that may be an issue with the set up of the cable remote. Also depending on weather or not the HDMI cable you are using supports audio, or the cable box HDMI out supports audio, may be another issue to look at. If your cable service does not offer 1080p HD programs or movies, then the HDMI cable is not neccessary anyway.