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Your experience with modifying raw loudspeaker drivers and the results.

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  • #16
    I'm not sure this qualifies as an improvement, but certainly as a modification. I've added bucking magnets to some drivers.
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    • #17
      what does that do ?¬*

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      • #18
        Originally posted by sdep777 View Post
        what does that do ?¬*
        From PartsExpress:
        These fully charged ferrite donut magnets have many uses. Can be used to add shielding to small woofers, midranges or tweeters, which allows speaker to be placed in close proximity of picture tubes and computer monitors. Commonly referred to as bucking or cancellation magnets. Simply attach the magnet (in reverse polarity) to the speaker back plate using epoxy or cyanoacrylate (super glue). As a general rule, the bucking magnet should be approximately 1/2 to 2/3 the size of the driver magnet. Limited availability

        *And also, as I understand it, bucking magnets push a bit more magnetic force into the gap, which causes a slight increase in efficiency.
        Last edited by ; 05-08-2018, 12:36 PM.

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        • #19
          Ratch Higgins showed me some before and after measurements of full range paper cone drivers that had been coated. There was a smoothing of the frequency response.

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          • #20
            Yea, in the 80s I used some Pioneer A11ec80-02F full range drivers that were paper cone and put them on an old turntable and used some white liquid that Mark from Meniscus Audio had showed me at his shop. Back then I lived in Holland Michigan so was only a 20 min drive to his shop, anyway they looked really glossy when dried and he told me it would stiffen the cone. kinda fun too.

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            • #21
              "I'm not sure this qualifies as an improvement, but certainly as a modification. I've added bucking magnets to some drivers."

              "What does that do?"


              The bucking magnet reduces the stray magnetic field (useful when TV's were cathode ray tubes), strengthens the magnetic field in the voice coil gap, and lowers the Qts.

              When installing, the bucking magnet magnetic field initially pushes away from the driver magnet. Then when the magnets are about 1/4" apart, they attract strongly, so watch your finger tips.

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              • #22
                Originally posted by View Post
                Ratch Higgins showed me some before and after measurements of full range paper cone drivers that had been coated. There was a smoothing of the frequency response.
                I've seen improvements with some applications, but also some made worse, much worse, especially smaller drivers like a midrange. Peaks were reduced but the overall response was more ragged. It also reduced the sensitivity. This is added mass after all, so anything more than careful, selected treatment will affect that. On a larger driver, the ratio of original mass vs. after-treatment mass may not be much different, but it's a crap shoot IMO. Surround treatment, when warranted, isn't as problematic.

                dlr
                WinPCD - Windows .NET Passive Crossover Designer

                Dave's Speaker Pages

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                • #23
                  I donít know if I would call it a crap shoot but the experience of doing a few dozen drivers helps a lot. I stick to stiffening on woofers because you can add resonances. stiffening the area out an inch in diameter from the voice coils works pretty well without adding too much mass or resonances. PVA is polyvinyl acetate and Mod Podge from craft stores works well for damping cones and even dome mids or tweeters. I do most my experimenting an EBay bargains or buyout drivers like the Aurasound woofers. You do this at your own risk but I not say donít do this at home kids. A couple of the more expensive drivers that I modded I bough used or restocked. Some of the woven glass cone like the Scanspeak Discovery line benefit from stiffening around the voice coil with epoxy and CF as well as damping both sides of the cone with Mod Podge. Most of the old Bextrene cone on classic British speakers were damped with PVA.
                  Last edited by fdieck; 05-09-2018, 08:13 AM.

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                  • #24
                    304 pages of inspiration. Mods if posting another forum's thread is improper please delete. No harm intended.

                    EnABL Processes - diyAudio

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                    • #25
                      Originally posted by djg View Post
                      This hobby is all about happiness. Normal is over rated. And I didn't say "dampening".
                      Yep, if you dampening those steel woofer baskets too much, they'll rust. LOL

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                      • #26
                        I don't¬*like my speakers raw. Medium to well done with a little season. I must be hungry! Off I go to dinner!
                        On the cheap diy. That is my motto - www.hifiposse.com

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                        • #27
                          Originally posted by hobbyhands View Post
                          I don't¬*like my speakers raw. Medium to well done with a little season. I must be hungry! Off I go to dinner!
                          I try not fry my speakers and like the mids warm and the tweeters not too hot....¬*

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