No stereo audio on Cable TV

[old_tv_nut]

This problem is NOT caused by wiring unless you are seeing obvious problems in the video as well.

Composite and component only carry video, not audio. You would need L and R baseband audio connections as well. If the HDMI is carrying audio, that should be stereo, unless there is some reason the cable system does not have stereo on the signals.

You mention a digital adapter that works - what is the signal source for that adapter? Is it over the air antenna or isw it cable? Is this adapter supplied by the cable company? What kind of TVs are you using? Are they analog or modern digital flat screen? Is the HDMI going to an HDMI connector on the set or through an HDMI to analog adapter?

Without exact details, no one can diagnose your problem.