Harmony Central Forums
Announcement Announcement Module
Collapse
No announcement yet.

I have heard about speakers catching on fire

Page Title Module
Move Remove Collapse









X
Conversation Detail Module
Collapse
  • Time
  • Show
Clear All
new posts

  • I have heard about speakers catching on fire

    Hello folk,

    I have heard about this happening but what causes this?  Pushing the speakers over their capabilities I think can be one and can it destroy the rider?


  • #2

    If the voice coil gets hot enough, it can ignite the surrounding paper in a pulped paper cone or dust cap. Used to be that with treated paper bobins, those too would ignite.

    It's fairly rare, but possible.

    -------------------------------------------------------------------------------------------------------------------------------------------------------------------
    Former product development engineer: Genz Benz, a KMC Music/Fender Musical Instruments Company, continuing factory level product support and service for Genz Benz

    Currently product development engineer: Mesa Boogie

    Comment


    • #3
      In my early days when my head was buried way up my ***, I smoked a set of Carvin boxes. You could literally see the smoke coming out of them. Not sure what went wrong but I was so green at the time it could have been anything.

      Comment


      • dcastar
        dcastar commented
        Editing a comment

        Skip to 15 for carnage


    • #4

      In general you will find this happen after an amplifier failure/problem that causes DC across the voice coil. The exact amount will depend on a lot of factors. But essentially what happens is that there is excessive heating allowing for a build of volitle gasses... when the voice coil opens, there is a small spark. If all of the conditions are correct, this small spark will contain enough engery to ignite the gases... and again, if all of the conditions are correct, there will be enough gases to ignite the cone.

      I have never seen this occur with AC. IME the ignition path (spark-gases-cone) is broken due to the air-flow induced by the cone motion.

      There are test methods to determine the points at which this could occur (I tech'ed on the research for EIA-636).

      Good judgment comes from experience, and a lot of that comes from bad judgment. -Will Rogershttp://facebook.com/SpitShineRocks

      Comment


      • DanBAP
        DanBAP commented
        Editing a comment

        I was once assisting on a session where the engineer got drunk and passed out at the console with the music looping and the speakers (Adam S3A's) all the way up. The clip lights were just on steady - no blinking.

         

        After a little bit, the ribbon tweeters started sparking and smoking, which is when I woke him up.

         

        -Dan.


      • Mutha Goose
        Mutha Goose commented
        Editing a comment

        Mutha Goose wrote:

        In general you will find this happen after an amplifier failure/problem that causes DC across the voice coil. The exact amount will depend on a lot of factors. But essentially what happens is that there is excessive heating allowing for a build of volitle gasses... when the voice coil opens, there is a small spark. If all of the conditions are correct, this small spark will contain enough engery to ignite the gases... and again, if all of the conditions are correct, there will be enough gases to ignite the cone.

        I have never seen this occur with AC. IME the ignition path (spark-gases-cone) is broken due to the air-flow induced by the cone motion.

        There are test methods to determine the points at which this could occur (I tech'ed on the research for EIA-636).


        I wasn't thinking about over-powering the snot out of a speaker... LOL! I guess I was thinking about closed systems and what happens within the context of a properly designed system.


    • #5

      Never happened with pro speakers, but when I was around 16, I got a new album for Christmas and decided to give it a listen in my room.  The speakers were old woodgrain stereo speakers that were hand-me-downs.  As I'm listening to the music, I start to smell something burning.  I look over to the speakers, and one is glowing orange.  All of sudden a ring appears as the cloth grill starts melting away, then a flame pop's up.  Panicing, I turned off the stereo and grabbed a pillow to beat the fire out.  Spent the rest of the day cleaning the black soot off of everything in my room, and mourning the loss of my favorite pillow.  I don't remember any more what the album was, but when I tell the story, I joke that it was Black Sabbath.

      Comment


      • RoadRanger
        RoadRanger commented
        Editing a comment

        vort wrote:

        I don't remember any more what the album was, but when I tell the story, I joke that it was Black Sabbath.


        That'll teach yah for playing it backwards .


    • #6

       As an experiment, I hooked up two Pioneer consumer stereo speakers (non pa speakers) to a power amp.

      they played for 20 minutes and then caught fire.

      Comment


      • dboomer
        dboomer commented
        Editing a comment
        I can't say whether the cause was AC or DC but since Dc will take out a speaker almost instantly I'm guessing AC is more of a problem. I've seen it happen with speakers rated at very high power levels too. I remember testing very high power woofers where the magnet was over 300 degrees so I'm guessing the temp could be double down in the gap. Now if you freeze up the vc and coil there could be some very high temps reach the cone.

        As you can guess manufacturers react quickly when the get such reports as liability can always come into play.

    • #7
      Add captain of a cruise ship to that list

      Comment



      Working...
      X