I just had True come and the installed wifi internet (looks like a "Thomson" router) and a cable box (IRH100C) and there is a buzzing when I watch the cable. It is quite annoying. BOTH the cable and the internet are being sourced from the same cable outlet, our only one. It seems to get better at times when I fiddle with the connections. When I watch movies on my connected hard drive, the noise goes away (thank goodness).

Any advice? Probably interference from something? Hopefully I gave enough info for people to help, let me know if you need more. Thanks in advance.

I actually just "fixed" this by turning up the volume on the cable box all the way. I think I have had this problem before, but in my haste and mistrust of Thai talent I blamed the box. Ha.

a simple 100v earth loop - earth the boxes and the TV and it will go away.

I actually just "fixed" this by turning up the volume on the cable box all the way. I think I have had this problem before, but in my haste and mistrust of Thai talent I blamed the box. Ha.

Try a balance between your TV volume and the settop box volume. I know with my TVs I get better audio quality on my TrueVisions boxes on cable and C/KU band boxes via dish by not having the TV's volume above 50% and then using the settop box volume control for volume adjustments. With my C/KU band box satellite boxes (hooked to my big black dish) it makes a big difference in audio quality as it greatly reduces hum which is probably 50Hz line voltage hum. I just set my TV volume to 50% and then never touch it again, except to check it everyone one in a while to make sure it hasn't been adjusted above 50% by mistake/accidental TV remote button pushing. Yeap, setting my TV volume to 50% max and then only using my settop box volume control makes a big difference in audio quality.