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  • Re: Scan-Speek 4" for 49 cents?

    Originally posted by jamikkim View Post
    I think it has to do with waves propagating outwards from the centre towards the edge - the slits mean that no wave can directly reach the edge without going through a slit. It means that reflections that may cause standing waves are attenuated due to the cut and the damping glue. It also will dampen radial waves as they can't form a ring without passing through many slits. As stated above the cone probably does move in different directions too, although if the slits are small enough then it shouldn't cause as much smearing due to a floppy cone - I think some of my experiments have too big of a gap... ;)

    [ATTACH=CONFIG]57838[/ATTACH]
    I'd like to hear more about your experiments. Did you take any measurements? Did you like the results? That looks like 100% silicone, which might be too rubbery? Did you try this before this thread?
    "Looks like you may have to design your own speakers. Its not that hard." -DE Focht

    Diffraction Happens

    Comment


    • Re: Scan-Speek 4" for 49 cents?

      I don't really have any proper measure equipment and the speakers are gone now ;p I will do more later though. It did change for the better though there was still a peak lower down, probably due to the larger splits and sealed driver.

      It was Selley's water based contact adhesive. No idea what it's made from but seems nicely visco-elastic - it's not a bouncy rubber, it stays sticky-ish and seems viscous when you stretch it and it's returning.
      If you have any suggestions for other types of glues then please tell ;p Not sure what would work best, harder glue or softer. I will try for smaller slits.

      I also cut it all the way to the surround so the cone was cut to the edge. I noticed yours stopped before then. Scanspeak one goes to the edge however I'm not sure whether the surround material is cut at all or not. I did try a larger speaker with a more rubbery type and even larger splits once, sounded ok but I just stuck it in my car with some large inductors which is gone now.

      Comment


      • Originally posted by NyxOne View Post
        Re: Scan-Speek 4" for 49 cents?



        Very interessting! I wonder what it could do for a an SB15 or SB17!

        Chuck
        Long wait, but...

        Click image for larger version

Name:	zzzzrev and sb15 sliced.jpg
Views:	482
Size:	247.0 KB
ID:	1435398

        Look for a shootout coming to a thread near you!
        Attached Files
        "Looks like you may have to design your own speakers. Its not that hard." -DE Focht

        Diffraction Happens

        Comment


        • Originally posted by jbruner View Post
          Long wait, but...
          I've considered doing that, haven't had the nerve to cut into reasonably good drivers. I would suggest using "The Wet Look", sold by P.E. in black and clear. Do it in stages, taking measurements at each stage to document the changes made.

          I've thought that the paper SB drivers are excellent candidates for improvement. Try the surround treatment with Wet Look. And on the cone slits as well, it's got excellent damping properties. It may improve resonance issued in the mid-band. Check out my page on this technique.

          Insignia Treatments

          dlr

          p.s. Gotta compliment you on the cut quality.
          WinPCD - Windows .NET Passive Crossover Designer

          Dave's Speaker Pages

          Comment


          • jbruner
            jbruner commented
            Editing a comment
            Today I used "the wet look" on some surrounds. I like the way it looks, but so far 2 coats hasn't completely killed the cone edge resonance. I'll keep trying.

        • Originally posted by dlr View Post
          I've considered doing that, haven't had the nerve to cut into reasonably good drivers. I would suggest using "The Wet Look", sold by P.E. in black and clear. Do it in stages, taking measurements at each stage to document the changes made.

          I've thought that the paper SB drivers are excellent candidates for improvement. Try the surround treatment with Wet Look. And on the cone slits as well, it's got excellent damping properties. It may improve resonance issued in the mid-band. Check out my page on this technique.

          .

          Ok, that was addressed 6 years ago in post #137.
          Let me be clear.
          Development of my slicing technique was complete 5 years ago.

          Forward thinking people must do their own experiments.
          Asking me to do it for you is rude.
          Really.
          Thank you for all the information you have generously shared in the past.
          "Looks like you may have to design your own speakers. Its not that hard." -DE Focht

          Diffraction Happens

          Comment


          • Originally posted by jbruner View Post
            Ok, that was addressed 6 years ago in post #137.
            Let me be clear.
            Development of my slicing technique was complete 5 years ago.

            Forward thinking people must do their own experiments.
            Asking me to do it for you is rude.
            Really.
            Thank you for all the information you have generously shared in the past.
            I didn't read through all previous parts of the thread, don't remember threads from 5-6 years ago, though what you were showing was interesting and was (apparently again) impressed by how well you made the cuts, but I don't think I'm the rude one. Excuse me for trying to be supportive.

            dlr
            WinPCD - Windows .NET Passive Crossover Designer

            Dave's Speaker Pages

            Comment


            • jbruner
              jbruner commented
              Editing a comment
              You were one of the people who were influential to me when I wanted to start modifying speakers. I visited your pages back then to learn about tweeter mods. I truly mean you no disrespect personally. This thread has a particular theme, though. I'm trying to promote science. Science is not polite.

          • When I saw this thread rekindled, I remembered seeing it originally. I knew I had a stash of 24/box buyout 5" drivers stuck away somewhere in a box. Well, with being stuck at home I finally dug back in a storage closet and found them. I have no pics at the moment, but will take a few and post them. I simply mimicked what JBruner had done and followed the scan slit cone pattern.

            In my case, I used calipers and slowly adjusted them until the outside of the cone was 5 widths of the caliper when rotating it around the outside of the cone (if you can follow that description). That gave an easy way to locate the outside edge of the slices at the surround. I marked these spots lightly with a yellow colored pencil. Then I made a similar set of marks half-way between those marks, which gave the location of the end of the second set of slices. I used the same process to locate the start of the slices around the dust cap, then drew light yellow lines between the marks as guides for the actual slices to be made. I also did one with and without the dust cap treatment. I didn't save the measurements, but the dust cap treatment was well worth doing, imo. Really only took a few minutes to do the mark up a driver and not that much longer to do the cuts.

            All I had on hand was some Aleene's tacky glue, so I put a bead of that down each line. It is a pretty sloppy job, but I had the time and didn't want to wait to get some other glue/sealer. I let it dry for a few hours before doing any measuring.

            The measurements below are made in an old ported mtm cabinet, with cardboard taped over the openings. The one opening was cut through the cardboard to fit the driver surface mounted with painters taped applied around the driver to hold it in place and help seal the cabinet. Not the ideal for pristine measurements, but I thought it would be good enough to get the job done for comparisons sake. One set of measurements were taken of a raw driver. The mic was 18" away, the gate was 4ms and it was up on a stand (indoors) with the mic about 60" high. Measurements were taken at 0-15-30-45º on the horizontal axis and then in the software, a summed response of those 4 was developed in post processing. Then the measurement was repeated with the treated driver. The untreated is on top, the treated on the bottom. This is just spl of course, no other measurements were done.

            I'll let you all interpret the results, but suffice to say I thought they showed a very valuable improvement.

            Next up I'm going to take a look at a 6.5" pro driver, the B&C 6md38 to see what improvements are had. ore pics and measurements later. Hats off to Jbruner for his original efforts and posts on this subject.

            Edit: I forgot to mention that no smoothing was applied.

            Click image for larger version  Name:	5in buyout no treat_VS_TREAT_18in_4ms-gate_0-15-30-45-sum.png Views:	0 Size:	576.6 KB ID:	1435979
            Dan N.

            Comment


            • jbruner
              jbruner commented
              Editing a comment
              I'm curious which buyout drivers they are. I may have the same ones.

            • dlneubec
              dlneubec commented
              Editing a comment
              I intend to take some photos and post them here, just haven't gotten to it yet. I will also see if there is any name/# on the box

          • WOW! What an improvement...

            When I had a bad PRV 5MR450-NDY driver I experimented on cutting when I pulled the cone just to see if I could do it. I used Permatex black silicone adhesive. 1- it's black, and 2- siliconized-latex based.
            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


            • Yeah, the Aleene's looks bad and probably dries too hard, so I think I will try something else next time. The Permatex black silicone latex base adhesive seems like a good idea. I need to go back and see what Jbruner used. I guess I'm gonna be visiting Amazon soon.
              Dan N.

              Comment


              • jbruner used DAP Alex Plus Clear (stated somewhere either in this thread or the PM180 thread). I see that it comes in black too. I'm not sure how many alternatives he tested, but this is what he settled on as the best that he tested.

                Comment


                • Originally posted by dlneubec View Post
                  When I saw this thread rekindled, I remembered seeing it originally. I knew I had a stash of 24/box buyout 5" drivers stuck away somewhere in a box. Well, with being stuck at home I finally dug back in a storage closet and found them. I have no pics at the moment, but will take a few and post them. I simply mimicked what JBruner had done and followed the scan slit cone pattern.

                  In my case, I used calipers and slowly adjusted them until the outside of the cone was 5 widths of the caliper when rotating it around the outside of the cone (if you can follow that description). That gave an easy way to locate the outside edge of the slices at the surround. I marked these spots lightly with a yellow colored pencil. Then I made a similar set of marks half-way between those marks, which gave the location of the end of the second set of slices. I used the same process to locate the start of the slices around the dust cap, then drew light yellow lines between the marks as guides for the actual slices to be made. I also did one with and without the dust cap treatment. I didn't save the measurements, but the dust cap treatment was well worth doing, imo. Really only took a few minutes to do the mark up a driver and not that much longer to do the cuts.

                  All I had on hand was some Aleene's tacky glue, so I put a bead of that down each line. It is a pretty sloppy job, but I had the time and didn't want to wait to get some other glue/sealer. I let it dry for a few hours before doing any measuring.


                  I also used the caliper method, but I didn't mark the cones. I use a set of cardboard guides to cut against. It's good to see people experimenting. The glue I use is very soft, so the slits don't need to be wide, or even go to the edge of the cone. The revelator uses stiffer glue, but their slits appear to be wider. If you want to clean up the very top end, look under the dustcap. There's a discussion about this also on DIY Audio forum.
                  "Looks like you may have to design your own speakers. Its not that hard." -DE Focht

                  Diffraction Happens

                  Comment


                  • Originally posted by jbruner View Post

                    Long wait, but...

                    Click image for larger version

Name:	zzzzrev and sb15 sliced.jpg
Views:	482
Size:	247.0 KB
ID:	1435398

                    Look for a shootout coming to a thread near you!
                    which driver is it? looks good side by side to the Rev

                    Comment


                    • jbruner
                      jbruner commented
                      Editing a comment
                      It's the SB15NRXC30-8-UC. These are as close a match as you could ask for.

                  • Originally posted by dlneubec View Post
                    When I saw this thread rekindled, I remembered seeing it originally. I knew I had a stash of 24/box buyout 5" drivers stuck away somewhere in a box. Well, with being stuck at home I finally dug back in a storage closet and found them. I have no pics at the moment, but will take a few and post them. I simply mimicked what JBruner had done and followed the scan slit cone pattern.

                    In my case, I used calipers and slowly adjusted them until the outside of the cone was 5 widths of the caliper when rotating it around the outside of the cone (if you can follow that description). That gave an easy way to locate the outside edge of the slices at the surround. I marked these spots lightly with a yellow colored pencil. Then I made a similar set of marks half-way between those marks, which gave the location of the end of the second set of slices. I used the same process to locate the start of the slices around the dust cap, then drew light yellow lines between the marks as guides for the actual slices to be made. I also did one with and without the dust cap treatment. I didn't save the measurements, but the dust cap treatment was well worth doing, imo. Really only took a few minutes to do the mark up a driver and not that much longer to do the cuts.

                    All I had on hand was some Aleene's tacky glue, so I put a bead of that down each line. It is a pretty sloppy job, but I had the time and didn't want to wait to get some other glue/sealer. I let it dry for a few hours before doing any measuring.

                    The measurements below are made in an old ported mtm cabinet, with cardboard taped over the openings. The one opening was cut through the cardboard to fit the driver surface mounted with painters taped applied around the driver to hold it in place and help seal the cabinet. Not the ideal for pristine measurements, but I thought it would be good enough to get the job done for comparisons sake. One set of measurements were taken of a raw driver. The mic was 18" away, the gate was 4ms and it was up on a stand (indoors) with the mic about 60" high. Measurements were taken at 0-15-30-45º on the horizontal axis and then in the software, a summed response of those 4 was developed in post processing. Then the measurement was repeated with the treated driver. The untreated is on top, the treated on the bottom. This is just spl of course, no other measurements were done.

                    I'll let you all interpret the results, but suffice to say I thought they showed a very valuable improvement.

                    Next up I'm going to take a look at a 6.5" pro driver, the B&C 6md38 to see what improvements are had. ore pics and measurements later. Hats off to Jbruner for his original efforts and posts on this subject.

                    Edit: I forgot to mention that no smoothing was applied.

                    Click image for larger version Name:	5in buyout no treat_VS_TREAT_18in_4ms-gate_0-15-30-45-sum.png Views:	0 Size:	576.6 KB ID:	1435979
                    the top end looks really smooth. didn't follow your caliper decription...

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