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  • #16
    Ben,
    Thanks for the info. I have to wonder if these mods might improve the response on the regular stock tweeter as well.
    Dan N.

    Comment


    • #17
      I suppose it's possible. The bump above resonance in the spec sheet that appears at 2.5kHz is no longer present in the impedance measurements after I modified the tweeters. It is highly likely that the energy storage that as there is no longer a problem. This also means that the dip or peak that would coincide with said energy storage should be eliminated.

      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:
      http://photobucket.com/Wolf-Speakers_and_more

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

      Comment


      • #18
        Thanks, Ben, your drawing and instructions are very useful. I did a tiny bit of exploratory work towards removing one cup from one of my pair; it will be very, very difficult to remove the cup, I think, while being able to reuse it, but that's my goal.
        Paul

        Comment


        • #19
          I found once you start trying to remove it, the edge gets chewed up pretty easily. You might try a heat-gun to maybe soften the glue, just don't overdo the heat and hurt something else.

          E6000 did hold well once dried, but I did have to clamp the cup on for about 12 hours with masking tape (also using the clear packaging cover on the face) to allow it to cure.

          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:
          http://photobucket.com/Wolf-Speakers_and_more

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

          Comment


          • #20
            I bet a hair-dryer could also prove beneficial if you don't have a heat gun.
            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:
            http://photobucket.com/Wolf-Speakers_and_more

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

            Comment


            • #21
              Thanks for the instructions. This is good news, as this appears to work.

              I removed the back from one of my "B" tweeters using a slighly modified technique as follows:

              1) I placed the supplied gasket in the clear cover that came with the tweeter and then set the tweeter face down into the clear cover, sealing the dome off completely.

              2) I sealed the clear cover to the tweeter with masking tape all around, to prevent plastic shaving from getting anywhere near the tweeter dome or voice coil.

              3) Then I used a fine hack saw blade to slowly grind a 1/16" gap all the way around the plastic cup where the cup meets the metal magnet material. I kept slowing cutting deeper and deeper until I hit the metal magnet material inside. As I did this, I had a vacuum cleaner attachement running and cleaned away all the plastic shavings as I went along.

              4) This created a 1/16" gap between the plastic cup and the tweeter magnet. I then used a metal putty knife to slowly pry around this newly created 1/16" gap, applying just a little pressure at a time, and slowly moving around the entire tweeter in circular fashion.

              5) At first, the putty knife did not appear to be lifting the plastic cup off. But after I went around the circle about 4 or 5 times, slowly applying an upward pressure, the glue slowly began to pull away and the plastic cup separated from the magnet with no damage.

              6) I found that if I became impatient and tried to pry the cap off too quickly, the edge of the plastic cup would start to break off a little bit. So, very slow prying action is the key. The cap is glued on very tightly, but the glue will streach and give way under a moderate amount of pressure. I did not apply heat, as I did not want to risk accidently melting the plastic.


              Once I had the cap off, I pulled the foam plug and replaced it with cotton balls and then re-measured with DATS-V2. I found that I could duplicate your results by adjusting the size of the ball just right. I found that I could adjust the Fs up and down from 500 to 1000Hz by adjusting the size of the cotton ball and also by adjusting how far I stuffed the cotton ball into the pole piece. When I get a chance, I'll post my DATS V2 data. I can also mount the tweeter on my test baffle and compare it to my set of golden tweeters that I purchased about a year ago.
              SideTowers: http://techtalk.parts-express.com/fo...corundum-build
              Totally Flat: http://techtalk.parts-express.com/fo...5-totally-flat
              Plumber's Delight: http://techtalk.parts-express.com/fo...notech-winners
              Linehopper: http://techtalk.parts-express.com/sh...Esoteric-build

              Comment


              • #22
                Did you change the cup stuffing or remove the felt?
                Just curious,
                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:
                http://photobucket.com/Wolf-Speakers_and_more

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

                Comment


                • #23
                  I think the key to this mod working so well is replacing the thin felt pieces in the back chamber with the Ultratouch. I tried to fix (mod) a pair of B stocks by attacking them from the front. I carefully removed the felt pad that sits behind the dome and over the vented pole piece. I removed the foam plug and replaced it with a cotton ball just like you did. Then I reinstalled the felt pad with a few tiny drops of super glue. The double hump impedance curve was only slightly improved. The damping material in the back chamber seems to be the cure. I'm going to cut mine off like Bill did and try the Ultratouch.
                  Craig

                  The lowest possible F3 box alignment is not always the best alignment.

                  Designing and building speaker projects are like playing with adult Lego Blocks for me.

                  Comment


                  • #24
                    Also did anyone measure with a back cup without stuffing the pole piece? That would mean pulling the foam plug and installing the back insulated cup?
                    John H

                    Synergy Horn, SLS-85, BMR-3L, Mini-TL, BR-2, Titan OB, B452, Udique, Vultus, Latus1, Seriatim, Aperivox,Pencil Tower

                    Comment


                    • #25
                      That would make the upper resonance reappear. I would not advise 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:
                      http://photobucket.com/Wolf-Speakers_and_more

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

                      Comment


                      • #26
                        What if you added a half dome, or similar shape object to the cap to reflect sound to the sides, or maybe add some barriers to diffract sound waves.

                        Comment


                        • #27
                          With something that is less than 1" away from the acoustic origin, I'd think that absorption and damping is the best bet.
                          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:
                          http://photobucket.com/Wolf-Speakers_and_more

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

                          Comment


                          • #28
                            This thread is way too tempting to not be apart of, so I had to tear into my set as well.

                            I was able to get the back cups off without too much damage. I started by warming up the sides of the cup with a heat gun on low to soften the glue. I then pinched the sides of the cup in a vise (red arrows in pic, Hope you don't mind me borrowing the pic Wolf)

                            Click image for larger version

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                            This causes the edge of the cup to deflect out and create a gap where the cup meats the magnet. I could then slowly work my way around the circumference and pry it away from the magnet. So the cup is still usable and in not too bad of a condition

                            So far I have only run some impedance sweeps in DATS, using different variations in pole stuffing, cup stuffing etc...

                            Here are a few results.

                            Stock...
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                            No cup or foam in vent

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                            Stock Felt in cup, no foam in vent
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                            Tight packed cup with no foam
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                            More to come

                            Comment


                            • #29

                              Tight packed cup foam in vent
                              Click image for larger version

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                              Vent taped off(blocked), no cup with no foam in vent
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                              Taped off Vent(Blocked) with foam in vent

                              Click image for larger version

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                              That's it for tonight. If I can get some time I'll try to take some response graphs of the same variations.
                              Last edited by GTPlus; 07-24-2019, 08:29 AM.

                              Comment


                              • #30
                                I did the same with the heat gun an pried the back cup off. It looks reusable. It does look like the pole foam might not be needed which matches what I heard elsewhere. Unfortunately my felt is in a storage unit box that I'm not getting to any time soon so my testing is going to be limited.
                                John H

                                Synergy Horn, SLS-85, BMR-3L, Mini-TL, BR-2, Titan OB, B452, Udique, Vultus, Latus1, Seriatim, Aperivox,Pencil Tower

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