Originally Posted by Cipher
Great thread, but I have to think there is too much variability here to accurately compare these results. Off the top of my head I can see the following differences amongst users causing issues:
1) Plasma mounted on wall vs on stand - maybe a wall mount helps to block/diminish the sound given the proximity of the plasma to the wall?
2) Plasma located in a room with carpets/drapes vs one with hard floors and uncovered windows
3) People testing buzzing with no volume vs those testing with volume on
4) Some people testing on darker content vs those testing on bright or all white content (ie worst case scenario)
5) Ambient room noise (eg someone next to kitchen with loud fridge, someone with a loud PVR that is always on)
Any of these individually, or in combination, could easily explain differences in people's perception of buzzing. I think it's time this forum came up with an objective approach to testing buzzing, especially since this is a "science" forum. Going forward, I think any testing/reporting for buzzing should include the following:
1) Identify plasma installation - wall mount or stand, and if your room contains carpets/drapes that may absorb the sound
2) Turn off volume on the TV/Receiver. Testing should occur without any programming sound.
3) Turn off all other sources of sound in the room
4) Test primarily on bright content. Putting up an all white slide would probably be best.
Now, if someone was to do all of the above, should they still consider their panel defective if they can hear buzzing from more than a few feet?
My friend who's 60" ST30 had to be repaired sits on a wood credenza in a big living room with bare hardwood floors, no carpets, and wooden shutters on all the windows, and hard plaster walls. When i first set up his TV for him it was virtually silent until the board failure caused a loud buzzing, then after it was repaired it was again silent as it was before. Me and his family have specifically listened for buzzing and we all agree that it can't be heard beyond a foot or so from the screen. I've set up over a dozen Plasmas for people and none of them buzzed excessively (some at 1 foot, some at 4ft, etc) and of all my other friends who have Plasmas only one had one (not a Panasonic) that i could hear slightly from her couch but she couldn't quite hear it unless she sat dead center in front of her screen (maybe 8 feet away). I just don't accept the notion that it's normal to be able to hear a Plasma buzz from anything close to a normal viewing position, because that has not been my experience over the past 12 years of scrutinizing these things.
Here's something i posted in the ST50 thread the other night before dinner:
"Right now i'm displaying the "whitest" slide show image on my 50GT50 in a silent room and i cannot hear any buzzing with my face a foot from the screen, but i can hear the fan on my Tivo below it and also the fan on my PC that's 15 feet away from the TV, and i can hear the fridge humming in the kitchen well beyond that. But i cannot hear any buzzing with my nose almost against the screen. When i put my head behind the TV then i can hear a little mosquito buzz from inside, but nothing from in front. This is what i consider to be normal operation, albeit on the better side of the range."
And a few hours ago we got woke up about 4am (friggin loud racoon vs cat fight right outside our bedroom window) and after i broke that up i was now wide awake so i took the opportunity to repeat the above test but this time in total 4:30am silence. My PC was off and i turned my AVR off then i brought up my brightest break-in images and brightest HD wallpaper images and put the TV into VIVID mode at 100% Contrast and when i hook my ear over the top rear of the cabinet i can hear the low level buzzing from inside. As soon as i move my ear to the front the buzzing greatly diminishes and by the time i'm a foot away from the screen i hear nothing. Zero. I sat there in silence and strain to hear the buzz but it's completely silent. All the while i am able to hear the quiet whirr of the fans on my Tivo and TWC DVR in the credenza below the TV, but nothing from the TV. When i repeat this test in Custom mode at 85% Contrast and Panel Brightness set to Mid the TV is actually a little quieter.
Maybe my GT50 is abnormally quiet, but it's a teensy bit quieter than my G10 in a bedroom which i can't hear beyond a few feet. My old 2005 42PX50U in the den has been getting louder over the years and we can hear it buzz from about 5 feet away on very bright scenes but not at all at our 10 foot viewing distance. This is by far the loudest of my four Plasmas, yet cannot be heard from the couch.
My 26" HP LCD TV also buzzes from one foot away FWIW.