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Plasma Buzzing - A reply from Panasonic

Discussion in 'Plasma TVs' started by novaya_zemla, Nov 8, 2004.

  1. novaya_zemla

    novaya_zemla
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    I can't remember writing to Panasonic but here's their reply...



    Thank you for your e-mail enquiry. Firstly, please accept my sincere
    apologies for the uncharacteristic delay in our response. Due to an
    unexpected increase in the number of contacts we have recently received we
    have been unable to provide as speedy a response as we would normally.

    In response, I routed your email to our technical advisors who have advised
    the following:

    Plasma panel buzzing is a normal phenomenon. They work on a totally
    different principle to colour televisions and have different operating
    characteristics.
    The level at which the operating buzz becomes noticeable is always
    subjective, one person may hear it whilst another does not.

    The following points help to understand the factors surrounding the
    buzzing:

    The picture scanning drive circuits operate at high frequencies and powers.
    It is these circuits that cause the buzzing sound. The circuits are used to
    create both the picture and reuse energy to keep the unit efficiency high
    and panel heat emission low. This over-heating control is very important on
    the panels that do not use fans i.e 37” and 42” The resulting loss of fans
    makes for a quieter panel operation.

    Due to the very high amount of power processing required, the 50” panels
    have 4 cooling fans which will also contribute to the overall noise these
    plasma panels will produce.

    The buzz will appear more concentrated at the sides of the unit since this
    is where the power circuit boards are situated.

    Because we do not employ cooling fans, the buzz may be heard in very quiet
    surroundings. Plasma buzzing is normal and will always occur, but the level
    of buzz is what matters.

    Generally speaking the buzz will only be heard in quiet surroundings [with
    low levels of audio from whatever sound system used] and with the user
    seated too close to the panel [less than12’ for 42” and 10’ for 37” panels.

    A typical scenario is using the panel in the middle of the night when
    listening to news broadcasts at low volume. In this situation buzz might be
    heard during the silent breaks in the audio, but not so much during speech.
    This is not abnormal nor does it indicate a faulty panel.

    If the buzz is heard above normal ambient daytime noise and audio levels at
    more that 12’ a problem might be present.

    The method of panel installation will also affect the amount of noise
    heard. Wall mounting the panel will cause buzz emitted from the back of the
    panel to be reflected off the wall and into the room more than if the unit
    is located on the pedestal which is seated 2 to 4 feet away.

    Hard wall surface i.e. painted/wooden panels will be more effective
    reflectors than say walls that are covered in softer finishes, wall papered
    or curtained.

    Changing the picture mode in the picture settings menu between
    dynamic/normal cinema will also reduce the level of perceived noise since
    this affects how much power the panel is processing and this the level of
    power produced.

    Having too much brightness and contrast with the dynamic mode setting on,
    can overdrive the panel and cause louder buzz levels with strong picture
    signals i.e. DVD or Sky digital signals. Changing these settings can lower
    the level of buzz produced. Use ‘normal’ picture mode and lower
    brightness/contrast settings to reduce this effect.

    It is normal for the buzz tone and level to change the picture content
    because the panel drive circuits are processing different amounts of power
    and adapting their drive cycles.

    Plasma panels do not run in total silence. They do buzz as a normal part of
    their operation but this level of buzz is quite low and may be
    intermittently noticed in quiet surroundings.

    Please ensure these facts are understood and check your panel against a
    dealers display unit before requesting service since abnormal levels of
    buzz are not always ‘abnormal’ but just the normal operating buzz of plasma
    technology.

    I trust that the above information will be of assistance to you. However,
    of course, if you should have any further queries, please do not hesitate
    to contact us on 08705 357357 or customer.care@panasonic.co.uk and we will endeavour to assist.

    I hope this helps anybody with a buzz
    :thumbsup:
     
  2. MAW

    MAW
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    Very balanced and honest, I'd say. The bit about contrast etc and it being in the nature of the drive circuits is particularly interesting for those who were considering whether a mains cable could help. Perhaps calibration will do more than just give you the best possible picture, as most people run contrast and brightness too high.
     
  3. zedzed

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    I received my 2nd panny today (from av-sales) and it buzzes just the same :(

    (well done for AV for sending me another one though - top marks go straight to the head of the class!)

    The Mrs. can hear it almost all the time and I can hear it if there is no audio/dialogue. To say I'm disappointed is an understatement.

    Interesting that they say "run the panel in normal mode" .... I'm wondering whether I should do that (currently in cinema mode) and also turn off all other processing (AGC, colour management etc.)? Perhaps the extra processing causes the buzzing? I'll report back on that one.

    On the brightness / contrast side I've got the panel set at -5 on both which seems reasonable to me. Thing is - it's just normal operation that cause it to buzz, and there's no discernable difference when it's displayed a very dark scene or a very bright one (which goes against what other people say).

    I guess what hacks me off more than anything is that I've been in to several stores (comet, dixons etc.) and literally put my ear to the back of the plasmas in the stores and I can hardly hear anything! Yet stand within a few feet of mine and it is /really/ noticable.

    Can this be down to "environmental" factors? MAW - what do you think - is it worth looking into the "power" side of things (as was mentioned in the other "buzzing" post) and attempting to get a "cleaner" source of power to the plasma?

    ZedZed
     
  4. MAW

    MAW
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    No point in power supply being 'cleaner'. None whatsoever, trust me. Environment, we all know it affects sound. I take it you have a minimalist room, wood or ceramic floor, plasterboard walls and ceiling? If so a visit to a shag pile rug shop, and some tapestries could cure your problem.
     
  5. njr

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    Not much help I know, but my new PW6 is pretty quiet although you can hear it buzzing if you turn the sound off and display a bright scene, much quieter with dark scenes.

    does the colour management do anything useful/discernable like reducing colour banding? Just interested as I was wavering between the 6 and 7 series and hopefully havent missed out on any really good features.
     
  6. johnnyhonk

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    Yes, this buzzing thing is contagious.

    Cos I was buzzing when I first got my plasma. :suicide:
     
  7. Joe Fernand

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    ZedZed

    The bussing noise is usually generated by ceramic components in the driver circuits - that's why it varies as the image gets brighter; adding power conditioners ahead of the power supply is unlikely to make a big difference in this case.

    Swapping out for a different panel from the same 'batch' usually results in no difference in noise level as if there is a 'built in' reason for the noise in a batch they will all produce the same level of noise.

    When PWD5's were at there worst someone came up with an Acoustic 'cushion' you applied to the wall at the rear of the Display - it may be worth a trawl through the forum archives.

    Best regards

    Joe
     
  8. zedzed

    zedzed
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    Plasterboard walls, but carpet flooring. Big soft leather sofa. I wouldn't say minimalist.

    Surroundings may be a factor in whether I can hear it from my seated position - but regardless of that it's still a loud buzz coming from the back of the panel when I go close to it (can be heard over audio from about 3 feet).

    Like I say - I've been in several shops and looked at plasma TVs and I've never heard buzzing from the back of a panel like mine does.

    I guess I've got no option but to live with it (I've had 2 plasmas now - I can't see AV sales being /that/ nice as to keep sending me one until I get one of the "silent" ones) .... but if I'd had heard the buzz like that in any of the store plasma TVs that I saw I'd probably have decided to wait 12 months and see what the LCD market was up to then. Yeah ... I'm /that/ :censored: off :suicide:

    (to top it all off the Mrs. is hacked off too .... "two grand for a TV that makes a buzzing noise when we had a perfectly good TV already" .... )

    ZedZed
     
  9. zedzed

    zedzed
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    The buzz (volume) doesn't vary at all regardless of what's been shown on screen. The pitch varies ever so slightly ... but even I'd admit that you have to be right next to the panel to hear that difference! The overall volume level (and hence annoyance factor!) remains the same.
    So there are "quiet" and "not so quiet" batches? Hmmmmm. Not a happy consumer that I've got one of the "not so quiet" ones ....although AV-sales have been good.
    I'll have a look and see. Not sure the Mrs. would be happy with that one! Is there /anything/ else that can be done at all? I notice from panasonics letter/email in the first post that they pretty much cover their backs - the buzz would have to be /really/ loud to be heard over normal (dialogue) TV at 12 feet. Jeez .... I'd be scared the panel was about to blow up if it was that loud! lol (at least I can still laugh!)

    Thanks for the info though Joe. Do you do home calibration or anything like that? I'd been interested in getting a professional opinion on my buzz level. I guess if you said it was fine then I'd know that my only option is to live with it.

    Cheers,

    ZedZed
     
  10. Joe Fernand

    Joe Fernand
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    ZedZed

    Happy to drop past at some point and apply a 'critical' ear to the problem - have the AV-Sales team had a chance to 'reference' the returned Display against any stock units?

    Best regards

    Joe
     
  11. novaya_zemla

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    Thought you would be interested... ZedZed, I am also on my second PW6 (although my transition from one 't' other wasn't quite as painless as yours!) and my buzz was just the same... For what it's worth my normal day time settings are (in Normal mode) Contrast -30 and Brightness -30. My evening setting (in Cinema mode) are Contrast -17 and Brightness -15 and to be honest I don't notice any buzz at these levels (and the picture is fab) In fact my Humax PVR is louder...
     
  12. zedzed

    zedzed
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    Hi Joe,

    Thanks for the offer - I'll keep it in mind :)

    AV-sales won't get my "old" panel til tomorrow at the earliest. The strange thing about that one is that (a) it was completely silent for almost a week (ear to the back of the panel and even then only barely audible) and (b) from week 2 onwards is started to buzz - and only buzzed loud enough to be heard if it was on for several hours. Again - no variation in buzz based on picture being displayed

    My new one buzzes to the same degree straight out the box - no "week of silence" this time.

    I'm off to turn the settings down from -5 to -15 and see if that makes any difference! :)

    I think I've found the thread you mentioned Joe re: sound proofing etc. I see that sticking (fire retardant) foam/proofing to the back of the panel isn't recommended. The Mrs. will go nuts if I tell her we need to stick something to the wall behind the TV ... so probably rules that option out :rolleyes:

    Oh .. turned off AGC, colour management, peak limit, etc. and it didn't make any difference.

    ZedZed

    p.s. Cheers Joe (and other posters too) ... this is definitely the best online community I've come across :)
     
  13. Dot Crawl

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    Not just Hitachi's then.
    I have been looking at what panel to buy for some time now and it's driving me nuts.
    Any more research and I will end up in a padded cell.

    At least THAT may help the buzz problem.

    It's a total nigtmare when such a large investment causes so much stress, I have decided to take a risk on the Hitachi Buzzer and hope for the best, I truely hope everyone on here can resolve all their problems with the manufacturer and don't let them fob you off. My mates Hitachi 42PD5300 is quieter than my CRT and I expect my 5200 to be the same. I'll let you know.
     
  14. MAW

    MAW
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    These 2 cases are relatively rare, dot crawl, you stand more chance of a buzzer with a Hitachi. But best of luck, it's certainly not every unit. I've sold about 300 Panasonic 6 series SD, installed and heard running all but 10 or so, and none of those have been back for buzzing. I can't believe all my clients are deaf, they are certainly not afraid to complain about everything else!
     
  15. TeresaTT

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    My PWD6 buzzes and really annoys me. I sit about eight feet away from it and hear the buzz during quite parts of programmes. It also varies wth brightness. However, my husband does not hear it at all. He can only hear it if he puts his ear a few inches away from the back of the plasma.

    My retailer came to check it out and he can't really hear it either. He pointed out that my clocks tick loudly. I realised that they are louder than the buzz and normally I don't 'hear' them at all. I don't even notice one of them chiming on the hour. So I have accepted the buzz, and sure enough it is bothering me less and less. I only notice it now and then and I'm getting much happier with the situation.

    It seems very strange to me that my husband can't hear the buzz at all from a few feet away as it's so obvious to me, especially when I switch the screen on and off. It just shows that different people have different levels of hearing. By the way. he's not deaf. Also, I am stressed out by the sound because my lovely, new, very expensive and long awaited purchase is not perfect. The stress is probably ampifying the buzz many times over in my mind. I will probably get totally used to the buzz, just I have with the louder clock ticking.
     
  16. kriswood5

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    My new Viera is silent. However, just had sky+ installed today and this buzzes really LOUD!!
     
  17. Andy C

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    My 37" Viera buzzes. The odd thing is it was silent for the first 4 days and then it started. I can only hear it during bright scenes with lots of white on screen, but when I do it's very noticable... I'm viewing from about 8ft away.

    The worrying thing I'm currently running on low contrast & brightness as I'm still under 200 hours... what will it be like when I turn things up a little?!


    Andy.
     
  18. Jasonjo

    Jasonjo
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    zedzed,

    I went through a similar process with AV-Sales (I think I gave you the link to the old thread???)...they were great and very patient. Just to be clear, I assume you are talking about a high-pitched buzzing noise?

    Weirdly enough I actually managed to get the quietest noise using the dynamic picture setting, which makes absolutely no sense - I just lowered the defaults values quite a bit...as I use a scaler I can alter the picture irrespective of the plasma settings luckily. Best thing I can recommend it go through all the picture settings in a deadly quiet room and see which is the best for you, thats what I did and found dynamic was the best...

    Since having a scaler I also noticed playing around with video frequencies made a bit of difference. In particular, NTSC or 60Hz DVD's make the panel buzz even more (not surprisingly based upon Pannys comments)

    With my current picture settings I now only notice the slight buzz in complete quiet when using NTSC or US DVD's. It is still there, but only when I "tune into it".

    JJ
     
  19. EpsomJames

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    I'm on my second PW6, the first was returned to the retailer because of buzzing which was very noticeable even from my sofa 10-12ft away. I've been running my 2nd one for 4 weeks now and it's much quieter, it certainly can't be heard from my sofa with no volume.

    I have plasterboard walls which certainly relect any noise, but my plasma is on a stand about 6 inches away from the wall.

    I'm running contrast -10 and brightness -15. But from some of the suggestions here, I'm wondering if I should reduce that further? IIRC when I first switched it on the brighness was 0 but the contrast was +25!

    James
     
  20. novaya_zemla

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    Having read some of the comments here I have tried Jasonjo's suggestion and set my PW6 up with Dynamic and -30 contrast, -30 brightness and -4 colour. Definately the way to go.... No buzz at all, good colour, great picture.

    Try it with all settings at -30 and cycle thru Normal, Auto, Cinema and Dynamic and listen to the difference (I tried it with a paused bright picture displayed) :clap:
     
  21. zedzed

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    Emmm, well to me it's just a buzz ... the same as you get from a light dimmer switch but louder.

    Sounds interesting ..... I'll try this tonight when I get it :) Thanks for the advice.

    ZedZed
     
  22. pjclark1

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    How strange that I can hear NO buzz from my PWD6
    (unless I stick my ear against the vents)
    My panny stands about 6" in front of a painted plaster wall
    I often watch MTV in total silence (totty watching), total silence
    And yes, I can hear my kitchen florescent lights buzzing, so I'm not deaf.
    Maybe I should start a new trend and return my plasma to av-sales cos it doesn't buzz & I want to be normal like everyone else.

    CInema mode, all the time.

    What would be fun is for a buzzing and non buzzing pair of people to
    get together and give an opinion on each others plasmas. So lets all
    get our addys compared on this thread, 2 of us must live in the same area.
    I live in Cornwall, any buzzers nearby?
     
  23. Unlight

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    Yep same here... Panasonic PWD6 and no audiable buzz coming off it (apart from the usual, stick your ear right up to the back).

    I think some people must hear things in their head!!
     
  24. MAW

    MAW
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    :rotfl: That explains it all! No seriously though, I have heard Epsomjames' 1st PW6 and it sounded like a jet taking off, a sort of whining noise, and no, it wasn't his bank manager shut in the cellar. My PWD is virtually silent, several members have seen/heard it, including James, so this experiment has in fact already been done, though not with a large sample. Fact is, some do buzz/whine and some do not. Mostly not I think, in fact when you consider how many are sold, it must be very few. A poll, anyone? Plasma reliability/satisfaction in general would be fascinating. Mods, what do you think?
     
  25. zedzed

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    Joe - when are you free to come round and give me your take on my sets buzzing? The Mrs. is driving me daft going on about it - and only an "expert" opinion will satisfy her!

    Let me know (via PM if appropriate) what you would charge for you opinion :)

    ZedZed

    p.s. Tried changing all my picture settings - doesn't matter if everythings at -30 or +30 in dynamic - the buzz is the same volume.
     
  26. zedzed

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    I'm in Edinburgh. Happy to compare sets with someone else in the area if they want.

    ZedZed
     
  27. Joe Fernand

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    zedzed

    Drop me a PM with contact details on and I'll give you a call.

    Best regards

    Joe
     
  28. bendo

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    Just had to say something.

    Next week (second week of Feb 2006) I go to court. I am taking the supplier of my Hitachi 42PD5200 and Hitachi themselves to court because the noise is so distracting.

    Once you have heard it, you cannot get it out of your head.

    Basically, before we took this rather drastic action, a Hitachi engineer was called out (twice) to check it out. The second time he arrived with a new transformer to try and make the noise go away. When he took the back off, he said it was not the transformer, and said it would have to go back to the workshop for testing.

    However about 2 weeks later I called to see what was happening, and the Head Honcho there stated that they could find no fault... Then why did they take it away? Chap just stated that the YSUS boards all make this noise. Unacceptable.

    So we get back to our supplier and ask for a refund because as stated in the Sale of Goods act, the product should be 'fit for purpose' and 'free from minor defects' - and I firmly believe that the noise, which increases in pitch depending on the brightness of the image, fits in the range of a minor defect. After all, I use it as a pure monitor - it only gets an S-Video feed.

    We have also requested that the hearing/case start at our home so that all parties can heard the set in situ (the judge did want me to take it in... but at 35 kilos, and without a van and adequate insurance, there was no way on earth we could really get it there).

    So watch this space, and I shall let you all know what happens.

    Wish me luck.

    bendo
     
  29. WSH

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    I'm sure the first 50PHD8 with the dead pixel buzzed less than the replacement I got without a dead pixel. I'm going to get some acoustic foam.
     

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