Originally Posted by kevin_barr
I don't follow this thread very well, but if you are saying that the Westy makes a sort of buzzy hum through the speakers at certain backlight settings that better system grounding MAY help, it is probably the difficulties of making a dimmable flourescent bulb. I don't know if they use a special ballast or triac or whatever, but I've had lots of interference issues with flourescent bulbs affecting my home automation setup, because of all the noise they inject into the powerline (I use X10 for home auto which sends signals through the powerline that get masked by the noise).
So certainly if the Westy skimped on power filtering the speaker amp would pick up noise from the backlight's power supply and create a buzzy hum added to the speaker sound from the noise, which would be better or worse depending on what the power supply components had to do to get a certain backlight level.
this kind of noise is a little different than the classic "ground loop" hum, which is actually a sound based on the 60 cycle current that makes up AC power. (even if the sound you hear is higher pitched than 60 hertz it could be a harmonic of the 60 hz sound causing the issue, but the speakers can't reproduce the very low pitch 60 hz so you only hear the harmonic). This kind of humm does NOT have a buzzy sound. If this is what you have, changing grounds will definitely help if you know where the bad loop is.
In audio recording studios (used to work at one) sometimes the solution was to actuall REMOVE a ground from one device so it becomes a "floating" ground, and the loop is broken that way. removing the power ground from a device can be dangerous, but most home AV gear isn't actually grounded anyway (no 3 prong power plug). Removing the ground from AV signals (RCA plugs, audio red/white or red/black AND video yellow, red/green/blue) means making a custom cable or trying to wrap paper around the female socket then pushing the male cable end onto the paper (that's the ground connection, and they all have the same chassis ground on the gadget in question, so do audio and video).
Unfortunately, even if you had the wiring diagram for DVI and HDMI maybe that ground would be hard to disable.
If removing a coax ground helps (the outer threaded connection) it might create another problem because that whole section of coax is going to become an antenna for things like cb radios and who knows what else, so your tv quality could start fluctuating a lot.
If you unplug everything except power from the Westy do you hear the hum?
Thank you for your answer!
you see that is the thing: i use my westy only as a monitor dissconecting speakers was the first thin I did.
There are only two cables running into the unit - power and DVI D from my geforce 6600gt
The flickering sound is most noticeable at backlight setting at a 100%. As I lower the backlight it is less audible, and at 30% it is practically non existent.
Though even at a 100% setting sometimes after 20 min it goes away for some time.
Another thing that contributes is: the more white is on the display the the stronger the audio is.
However it goes without saying that is it incomparable to my 50 inch Akai plasma that sounded like a vacuum cleaner.
I got the impression that sounds comes from the back almost from the place of DVI connection. I am yet to try to connect to VGA and see what happens.
The sound is audible in a complete quiet room...