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Just caught my speaker on fire!

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  • Just caught my speaker on fire!

    Wow! I was playing my Queen Live in Montreal DVD tonight on my Mini Statements. I was playing at pretty high volume and kept bumping up the volume, but really being careful to stay below distortion levels. About a half hour into the DVD my daughter worked her way front row. I'm kind of smiling getting a kick out of it right behind her. We hear what sounded like the woofer bottom out. Kind of surprised me because it wasn't bass heavy. We look at each other so I turn it down a couple notches. My wife is out on the deck watching through the slider and comes running in and says there is smoke coming out of your speaker. I look at her like yeah right. So I walk up to the speaker to see what she is talking about and sure enough I smell smoke from the ribbon. Everything is still playing. I backed the volume way down and all the drivers sound fine. After about 10 minutes I put my hand on the back of the speaker and its warm. This can't be good. So I pull one of the woofers out. Unbelievable there was no sign of distortion at all. I can't believe I could get something that hot and not even know it.










    http://www.pellegreneacoustics.com/

    Trench Seam Method for MDF
    https://picasaweb.google.com/101632266659473725850

  • #2
    Re: Just caught my speaker on fire!

    Holy crap! thats awesome and sad at the same time

    Comment


    • #3
      Yikes!!!

      What seemed to give up the ghost?

      I've never had one do that...
      Later,
      Wolf
      "Wolf, you shall now be known as "King of the Zip ties." -Pete00t
      "Wolf and speakers equivalent to Picasso and 'Blue'" -dantheman
      "He is a true ambassador for this forum and speaker DIY in general." -Ed Froste
      "We're all in this together, so keep your stick on the ice!" - Red Green aka Steve Smith

      *InDIYana event website*

      Photobucket pages:
      https://app.photobucket.com/u/wolf_teeth_speaker

      My blog/writeups/thoughts here at PE:
      http://techtalk.parts-express.com/blog.php?u=4102

      Comment


      • #4
        Re: Yikes!!!

        Originally posted by Wolf View Post
        What seemed to give up the ghost?

        I've never had one do that...
        Later,
        Wolf
        I am really shocked. My wife did say that's the loudest she has hear me play it. Still I was listening closely for distortion. It looks like the resistor got hot, but wow! To get that hot to burn.
        http://www.pellegreneacoustics.com/

        Trench Seam Method for MDF
        https://picasaweb.google.com/101632266659473725850

        Comment


        • #5
          Re: Just caught my speaker on fire!

          There doesn't seem to be anything visually wrong with the resistor either.
          http://www.pellegreneacoustics.com/

          Trench Seam Method for MDF
          https://picasaweb.google.com/101632266659473725850

          Comment


          • #6
            Re: Just caught my speaker on fire!

            Dave- get some of these....

            http://www.mouser.com/Search/Refine....user_NoResults

            That'll fix it...
            Wolf
            "Wolf, you shall now be known as "King of the Zip ties." -Pete00t
            "Wolf and speakers equivalent to Picasso and 'Blue'" -dantheman
            "He is a true ambassador for this forum and speaker DIY in general." -Ed Froste
            "We're all in this together, so keep your stick on the ice!" - Red Green aka Steve Smith

            *InDIYana event website*

            Photobucket pages:
            https://app.photobucket.com/u/wolf_teeth_speaker

            My blog/writeups/thoughts here at PE:
            http://techtalk.parts-express.com/blog.php?u=4102

            Comment


            • #7
              Re: Just caught my speaker on fire!

              Rock on dude! Way to celebrate the birthday of the USA!
              Vapor Audio

              Comment


              • #8
                Re: Just caught my speaker on fire!

                Originally posted by DoubleTap View Post
                Rock on dude! Way to celebrate the birthday of the USA!
                :D
                http://www.pellegreneacoustics.com/

                Trench Seam Method for MDF
                https://picasaweb.google.com/101632266659473725850

                Comment


                • #9
                  Re: Just caught my speaker on fire!

                  I'm becoming a fan of outboard XOs!!!

                  Better ventilation.
                  R = h/(2*pi*m*c) and don't you forget it! || Periodic Table as redrawn by Marshall Freerks and Ignatius Schumacher || King Crimson Radio
                  Byzantium Project & Build Thread || MiniByzy Build Thread || 3 x Peerless 850439 HDS 3-way || 8" 2-way - RS28A/B&C8BG51

                  95% of Climate Models Agree: The Observations Must be Wrong
                  "Gravitational systems are the ashes of prior electrical systems.". - Hannes Alfven, Nobel Laureate, Plasma physicist.

                  Comment


                  • #10
                    Re: Just caught my speaker on fire!

                    I'm becoming a fan of outboard XOs!!!

                    Better ventilation.
                    I could have been keeping an eye on things a whole lot better that way. Had no idea things can get that hot.
                    http://www.pellegreneacoustics.com/

                    Trench Seam Method for MDF
                    https://picasaweb.google.com/101632266659473725850

                    Comment


                    • #11
                      Re: Just caught my speaker on fire!

                      From what it looks like Dave, it was the 4 ohm shunt resistor in the mid network that failed, and the good news is, it is unlikely that it did any other damage when it went. The cable ties on the 1 ohm series resistor look a little discolored as well, but maybe this was just from being adjacent to the shunt resistor, I can't tell from here.

                      This is the first MiniStatement network failure that I am aware of. You can tell your wife and daughter that it was the designer's fault (me) and not yours, as I didn't anticipate them being played at such high SPL's. -Or maybe it was because I never auditioned that particular Queen CD on them...

                      In any case, I'm glad the damage was limited to the resistor and board, and I apologize for the scare it must have given you and your family.

                      I would suggest you rebuild both mid networks with the following modification:

                      Replace the 4 ohm resistor with two 8 ohm resistors in parallel. This will double the power dissipation to 20 watts. If the 1 ohm looks like it has been overheating, replace it also with two 2 ohm resistors in parallel. None of the other resistors in the design should need to be replaced or modified, but if you see any other indication of overheating, please let me know, so we can address it.

                      When installing them, make sure the resistors are mounted so they are not flush to the board. This allows airflow on all sides. In addition, insure the crossovers are not covered with foam or stuffing. They need airflow to provide their rated power dissipation.

                      If I can be of any further assistance please let me know either here, or by email.

                      C
                      Curt's Speaker Design Works

                      "It is the mark of an educated mind to be able to entertain a thought without accepting it."
                      - Aristotle

                      Comment


                      • #12
                        Re: Just caught my speaker on fire!

                        Crack-pot engineering!:eek:

                        Nah! Just kidding!:D (Hey! Don't throw that shoe at me!)

                        I've never heard of that happening before. Was anything else in the box charred?
                        "Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy." --Winston Churchill

                        Comment


                        • #13
                          Re: Just caught my speaker on fire!

                          Originally posted by curt_c View Post
                          From what it looks like Dave, it was the 4 ohm shunt resistor in the mid network that failed, and the good news is, it is unlikely that it did any other damage when it went. The cable ties on the 1 ohm series resistor look a little discolored as well, but maybe this was just from being adjacent to the shunt resistor, I can't tell from here.

                          This is the first MiniStatement network failure that I am aware of. You can tell your wife and daughter that it was the designer's fault (me) and not yours, as I didn't anticipate them being played at such high SPL's. -Or maybe it was because I never auditioned that particular Queen CD on them...

                          In any case, I'm glad the damage was limited to the resistor and board, and I apologize for the scare it must have given you and your family.

                          I would suggest you rebuild both mid networks with the following modification:

                          Replace the 4 ohm resistor with two 8 ohm resistors in parallel. This will double the power dissipation to 20 watts. If the 1 ohm looks like it has been overheating, replace it also with two 2 ohm resistors in parallel. None of the other resistors in the design should need to be replaced or modified, but if you see any other indication of overheating, please let me know, so we can address it.

                          When installing them, make sure the resistors are mounted so they are not flush to the board. This allows airflow on all sides. In addition, insure the crossovers are not covered with foam or stuffing. They need airflow to provide their rated power dissipation.

                          If I can be of any further assistance please let me know either here, or by email.

                          C
                          You are right it is the shunt resistor. By no means was this your fault or a design flaw. I was pushing them very hard with my QSC GX3. I believe is rated at 450 watts per channel at 4 ohms.
                          I was thinking the same thing paralleling the resistors. I am just happy I didn't do anything to the ribbons. That was my biggest concern. There is also some melted foam so that probably had something to do with it also.

                          I guess it should tell you something about the volume when my wife was sitting outside watching the DVD through the sliding glass doors.

                          It is also a really rocken DVD. I was trying to hold back a few notches for the end when Freddy comes out in his white shorts. :o Anyway what an amazing voice he had.
                          Dave
                          http://www.pellegreneacoustics.com/

                          Trench Seam Method for MDF
                          https://picasaweb.google.com/101632266659473725850

                          Comment


                          • #14
                            Re: Just caught my speaker on fire!

                            I should also ad what a geek my daughter is. As I'm pulling out smoking parts she's snapping pictures so I can post them on techtalk.

                            Dave
                            http://www.pellegreneacoustics.com/

                            Trench Seam Method for MDF
                            https://picasaweb.google.com/101632266659473725850

                            Comment


                            • #15
                              Re: Just caught my speaker on fire!

                              Another option would be using higher wattage Arcol or Vishay/Dale non-inductive resistors. They can be purchased at Mouser Electronics.

                              I agree, Freddie was a great singer/songwriter, and Queen's music was meant to be heard LOUD...

                              C
                              Curt's Speaker Design Works

                              "It is the mark of an educated mind to be able to entertain a thought without accepting it."
                              - Aristotle

                              Comment

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