Any risk to speakers when the source sends bad signals?

Discussion in 'Speakers & Subwoofers' started by Cagri, Aug 26, 2003.

  1. Cagri

    Cagri Second Unit

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    Sometimes in the middle of a movie suddenly my DVD player spoils the picture and the sound for several seconds. It seems it's not the discs themselves, at least most of the time cause when I play the discs on my computer this generally doesn't happen. Sometimes it's the disc though. It's not only the picture, but the sound gets damaged as well, it's like loud cracks and rattles and buzzing for several seconds and then the player gets locked, I have to reinsert the disc and skip that part to avoid this problem. I'll replace the player in the near future, but is this going to cause any damage to the speakers like clipped signal waves do?
     
  2. DonnyD

    DonnyD Screenwriter

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    Any interference has the potential to do damage. Must be some badly handled discs you are playing. That's one of my pet peeves... no one handles my discs.
    That being said, a rental that is abraded only makes my video freeze and never transfers any sound artifacts through the receiver.
     
  3. Cagri

    Cagri Second Unit

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    Yes it usually happens with the rentals, but sometimes with new DVDs too... That's why I suspect the player. It plays for several seconds before freezing the picture which is enough to hear those terrible sound coming from the speakers unfortunately. The player is an old Pioneer dv515, I wonder if new players have such a feature making them stop when they detect something wrong on the disc..

    On a side note, no one can tell that my discs have been taken out of their cases, they are like new, not even a piece of dust on them. But when a friend asks for borrowing one, I can't say no and they usually come back with scratches on them. I'm not talking about big scratches, they are even hard to see unless you look at them from the correct angle and light but still it makes me mad. I still can't say no though :b
     
  4. DonnyD

    DonnyD Screenwriter

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    I have definitely learned to say NO... but that was after several on my discs came back from my brothers with scratches and LOTR was actually cracked! Seems that his stepkids would take them home with them and watch or his grandbabies would play with them.
    I also had a neighbor who would just bully her way in while I wan't here and grab a few dvds and take a month to bring them back. It would just burn me up... thank goodness she moved. Her children tore up several of my childs toys so I can just imagine what my disc went through.....
    You popping may well be your old dvd player and its just developed a loose connection or something. New players are really inexpensive now and as I mentioned, mine (Toshiba 4700) never transfers any audio mess to my sytem.
    Good luck and find a way to say NO....
     
  5. Cagri

    Cagri Second Unit

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    Thinking about it, I can't figure how a digital signal, although somehow messy, can damage a speaker. It's 1s and 0s passed to the receiver, right? And the receiver doesn't care if 1s and 0s are passed through as they should be or not, does it? The sound produced may not be pleasent but the signal should still be a fine one... Am I wrong?

    By the way, please feel free to move the thread if it doesn't belong to this forum.
     
  6. Jack Briggs

    Jack Briggs Executive Producer

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    Cagri, extreme high-frequency noises at high amplitude can cause a tweeter's voice coil to melt. Loud transients have been known to knock cone drivers out of their baskets. So it pays to be careful. And it pays, when it comes to lending DVDs, to learn to Just Say No.
     
  7. Michael R Price

    Michael R Price Screenwriter

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    If the interference is way loud, it could hurt your speakers. But if it's at the same level as the rest of the sound from the movie, I wouldn't worry about it.
     
  8. ChrisLazarko

    ChrisLazarko Supporting Actor

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    Thats odd that you have that problem. Are the discs very badly damaged. I owned an old Philips Magnavox DVD player from 1996 and it played DVD's fantastic until I retired it in 2002, even rentals. It only had a problem once and that was because of a bad disc...
     
  9. Cagri

    Cagri Second Unit

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    No the discs aren't very badly damaged, just tiny scratches and some fingerprint on them. Sometimes it happens with brand new discs too. The other night I was watching a clean rental copy of The Shining (Stephen King's) for example, and at the end of the second disc it suddenly did that, it plays a pixelised (don't know how to tell it better) picture and very bad audio for 5 to 10 seconds then freezes. I am guessing that it does it when it works hard and gets hot as last night I watched the same scene (after wiping the disc) and it was OK. I used this player long time on top of a VCR with no breathing space. Although DVD players don't get too hot, it may have got hurt.
     
  10. Jack Briggs

    Jack Briggs Executive Producer

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    Cagri, actually DVD players run very hot. The chassis prevents you from noticing this for the most part.
     
  11. John Royster

    John Royster Screenwriter

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    Sounds like Cargi needs a new DVD player?
     
  12. Cagri

    Cagri Second Unit

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    You're right Jack, even the discs are very hot when you take them out. I was meaning to say that they seem to deal with the heat issue inside with no need of vents, so stacking them shouldn't be a very bad idea I hoped, although I knew it wasn't wise [​IMG]

    John, I know I do [​IMG] It's just I also need a new bike, and new surrounds too [​IMG]
     
  13. alan halvorson

    alan halvorson Cinematographer

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    Here is my experience. I used to own a pair of Boulder 500 stereo amplifiers which I used in their bridged mono configuration. These amps were DC-coupled. That means there were no capacitors to prevent a pure DC signal from passing through to the speakers. The idea was to improve bass performance. Speakers, however, don't like DC and will very likely be damaged by such a signal. Most amps connect a capacitor across their outputs; capacitors won't pass DC (at least they're not supposed to). The Boulder instead incorporated a DC-offset detection circuit that would mute the amp if the offset exceeded a set value.

    I was playing a laser disc I had just bought used. Something was wrong with this disc - my player, at the time and still is, a Pioneer LD-S2, can track nearly any laser disc but it could not track this disc. The picture was nothing but distortion, but even worse, a DC pulse was sent to the amplifiers. That's when I found out that speaker protection is a good idea - the amp immediately muted and my speakers (quite expensive ones) were saved. I got that disc out of my player pronto and the amp returned to normal.

    So, yes, a bad signal can damage your speakers. Most likely to go would be the tweeter. Get that new player now or your current one serviced!
     
  14. Greg Conti

    Greg Conti Stunt Coordinator

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    A buddy of mine had a surround processor that would send out noise everytime he paused, skipped chapters, etc., using a HTPC. Burned out most of the tweeters (I think 11 of them!!!) in his B&W THX system. B&W did replace them free of charge.
     

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