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Scan-Speek 4" for 49 cents?

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  • #46
    Re: Scan-Speek 4" for 49 cents?

    I would think that wood glue would damp more than stiffen. Are not the slits designed to do the absorption of the breakup resonances? Then why damp the cone further? I would think you would want to stiffen the cone so that the slits do all the absorption. Just typing my thoughts
    Caleb b

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    • #47
      Re: Scan-Speek 4" for 49 cents?

      Originally posted by jbruner View Post
      A wood glue coated cone and an uncut caulk striped cone are dry for when I get back in a day or two. I already tried the surround/cone edge damping that Johnny suggested, and the effect was small. That is something I have been doing for years. I'll have to find another sample for that one.
      Try this as a test. These are small bits of a non-drying putty of some kind.

      Click image for larger version

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      This is a KEF (Celestion) F15 driver in a 2-way. I tried a lot of variations, but never slit the cone. I didn't want to risk destroying it, though I was very interested in the SS technique. I tried it and a couple of variations of added damping material. The result was actually fairly good, but the arrangement above was the best result in what I tested.

      Click image for larger version

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      The best single improvement was with the application of the damping at the inner edge of the surround, in the case it is "The Wet Look" purchased from PE. Took several applications (same thing when I modded other drivers). This is the same thing that a lot manufacturers do, SS included. They had (still have?) a small bottle now that is something like $5. Well worth it for experimenting and I suspect far better for damping than silicon caulk or similar. The full set of tests (SPL, no distortion) are described at the link.

      KEF driver tests

      dlr
      Last edited by dlr; 05-04-2014, 09:59 AM. Reason: Added measurements of before/after treatment
      WinPCD - Windows .NET Passive Crossover Designer

      Dave's Speaker Pages

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      • #48
        Re: Scan-Speek 4" for 49 cents?

        hmm. I have a couple er18rnx that have been sitting around for a while. If I could find a way to accurately cut the slits I would try it.

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        • #49
          Re: Scan-Speek 4" for 49 cents?

          Originally posted by killa View Post
          hmm. I have a couple er18rnx that have been sitting around for a while. If I could find a way to accurately cut the slits I would try it.

          Why? The response of the ER18RNX is already quite smooth whereas the NSB was anything but.
          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
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          • #50
            Re: Scan-Speek 4" for 49 cents?

            Originally posted by dlr View Post
            Try this as a test. These are small bits of a non-drying putty of some kind.

            [ATTACH=CONFIG]46626[/ATTACH]
            This is a KEF (Celestion) F15 driver in a 2-way. I tried a lot of variations, but never slit the cone. I didn't want to risk destroying it, though I was very interested in the SS technique. I tried it and a couple of variations of added damping material. The result was actually fairly good, but the arrangement above was the best result in what I tested.

            [ATTACH=CONFIG]46627[/ATTACH]

            The best single improvement was with the application of the damping at the inner edge of the surround, in the case it is "The Wet Look" purchased from PE. Took several applications (same thing when I modded other drivers). This is the same thing that a lot manufacturers do, SS included. They had (still have?) a small bottle now that is something like $5. Well worth it for experimenting and I suspect far better for damping than silicon caulk or similar. The full set of tests (SPL, no distortion) are described at the link.

            KEF driver tests

            dlr
            I think these could be worth a try:

            Click image for larger version

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            • #51
              Re: Scan-Speek 4" for 49 cents?

              Originally posted by fatmarley View Post
              I think these could be worth a try:

              [ATTACH=CONFIG]46628[/ATTACH]
              I was thinking the same thing only with various round foam stickies and foam tape.
              "We are just statistics, born to consume resources."
              ~Horace~, 65-8 BC

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              • #52
                Re: Scan-Speek 4" for 49 cents?

                Why? The response of the ER18RNX is already quite smooth whereas the NSB was anything but.
                Why. Because I can. I am willing to bet the revelators would still be smooth without the slits. Perhaps in the case of the revalators it is a marketing tactic to drive up the price :eek: While they are great drivers the slit cone may not be the reason. If it is these slits might also improve the seas driver.

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                • #53
                  Re: Scan-Speek 4" for 49 cents?

                  Originally posted by dlr View Post

                  [ATTACH=CONFIG]46626[/ATTACH]


                  dlr
                  Cool, a speaker with freckles! I would be more likely to try something like this without destroying the cone. At least it is modifiable and reversible.
                  “I cried because I had no shoes until I met a man who had no feet”

                  If we all did the things we are capable of doing, we would literally ASTOUND ourselves - Thomas A. Edison

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                  • #54
                    Re: Scan-Speek 4" for 49 cents?

                    Originally posted by fatmarley View Post
                    I think these could be worth a try:

                    [ATTACH=CONFIG]46628[/ATTACH]
                    They might work. My thought back then was that for the dots, it was more a case of added mass than any damping effects. This would alter the resonances in the cone. It took surprisingly few.

                    dlr
                    WinPCD - Windows .NET Passive Crossover Designer

                    Dave's Speaker Pages

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                    • #55
                      Re: Scan-Speek 4" for 49 cents?

                      All of this reminds me of the EnABL process that has been kicking around diyaudio for a long time. Here's a link to a diyaudio thread that explains the process:

                      http://www.diyaudio.com/forums/full-...-speakers.html
                      "Everything is nothing without a high sound quality." (Sure Electronics)

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                      • #56
                        Re: Scan-Speek 4" for 49 cents?

                        I'll post the test results for samples 3 and 4 tomorrow.

                        First, I'd like to see some predictions from the audience.(SQ, breakup changes?)

                        Sample 3- (no dust cap) unblemished cone coated with wood glue.



                        Sample 4- Flexible glue at surround/cone edge only.
                        Sample 4- Uncut cone with thick stripes of flexible glue in the same positions as the slit cone, along with the cone edge treatment.

                        Pic shows glue still wet-it dried clear.
                        "Looks like you may have to design your own speakers. Its not that hard." -DE Focht

                        Diffraction Happens

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                        • #57
                          Re: Scan-Speek 4" for 49 cents?

                          How thick did you apply the wood glue did you thin it with water?
                          Caleb b

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                          • #58
                            Re: Scan-Speek 4" for 49 cents?

                            Originally posted by caleb View Post
                            How thick did you apply the wood glue did you thin it with water?
                            Full strength, went on pretty thick in one coat.

                            "Looks like you may have to design your own speakers. Its not that hard." -DE Focht

                            Diffraction Happens

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                            • #59
                              Re: Scan-Speek 4" for 49 cents?

                              Well you already said the edge treatment didn't change things much. As for the wood glue treated, I would guess the the first signs of breakup maybe pushed down to 5k and spread out 3 db lower as well as to top end rolling off quicker. I doubt the thick stripes of flexible glue will be nearly as effective as the slits.
                              Caleb b

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                              • #60
                                Re: Scan-Speek 4" for 49 cents?

                                I would expect that Sample 3 will be in the "pretty nice midrange" territory now. Tweeter mandatory.

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