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  • #16
    there is this AMT that turn2 mentioned
    https://www.parts-express.com/dayton...8-ohm--275-095

    not a low FS, but I've become a fan of the AMTs after making TomZ's Bantams with the AMTPOD tweeters.

    Comment


    • #17
      I maybe got ahead of the process a bit with the tweeter post, but I wanted to post this graphic -

      This is how I do the initial design on just about every speaker -

      Unibox or winiSD to find box size/alignment
      Box Design
      1) Start with a swag for baffle width based on driver size
      2) port summary
      3) port specifics, including volume consumed
      4) exact net internal volume
      5) estimate of baffle height. Figure box depth based on 1 and 4

      Wow, I just figured out something about this forum software. I refuses to load an image in portrait orientation.
      Rotated the image twice, and the forum still shows this orientation.

      I think I hear a difference - wow, it's amazing!" Ethan Winer: audio myths
      "As God is my witness I'll never be without a good pair of speakers!" Scarlett O'Hara

      High value, high quality RS150/TB28-537SH bookshelf - TARGAS NLA!
      SB13/Vifa BC25SC06 MTM DCR Galeons-SB13-MTM
      My Voxel min sub Yet-another-Voxel-build

      Tangband W6-sub

      Comment


      • #18
        Originally posted by ceiol View Post
        there is this AMT that turn2 mentioned
        https://www.parts-express.com/dayton...8-ohm--275-095

        not a low FS, but I've become a fan of the AMTs after making TomZ's Bantams with the AMTPOD tweeters.

        Thanks - sort of worried about the bumpy response on that model, but everything I"ve heard about AMTs sounds
        like what I like for a tweeter.

        I think I hear a difference - wow, it's amazing!" Ethan Winer: audio myths
        "As God is my witness I'll never be without a good pair of speakers!" Scarlett O'Hara

        High value, high quality RS150/TB28-537SH bookshelf - TARGAS NLA!
        SB13/Vifa BC25SC06 MTM DCR Galeons-SB13-MTM
        My Voxel min sub Yet-another-Voxel-build

        Tangband W6-sub

        Comment


        • #19
          Tweeter Testing:

          I ordered 2 pairs of $35 tweeters, with the intention that one would turn out to be superior, and I'd send
          the loser pair back. I'd also like a smallish tweeter since the mid--wooofer is a 4 incher, but that's a "nice to have", not a "must have"
          I decided to test distortion at 75dB and 85dB, and got some surprising results.
          I ran all tests with a 3rd order crossover, 10uF, .30mh, 10uF so I would not stress the units.
          I'll probably cross any of the tweeters about 3Khz oor higher to the AXT-04

          For a quick series of tests, I just surface mounted them. That definitely affected on-axis FR, but I figured that a real world
          box and flush mounting would smooth out the FR.

          https://www.parts-express.com/tang-b...eeter--264-866

          First up the Tangband 25-1744S ceramic. I loved the cosmetics and it was small.

          I never snapped the graph at 75dB, it looked very good, about .46 percent max distorition.
          Here is the 85dB test, about 1.25 percent second order at about 2.8Khz.
          A bit higher than I'd expected, so them went back in the box.
          Click image for larger version

Name:	TB1744-2nd and 3rd HD at 85dB  1.25 percent max.png
Views:	1
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ID:	1348369

          I think I hear a difference - wow, it's amazing!" Ethan Winer: audio myths
          "As God is my witness I'll never be without a good pair of speakers!" Scarlett O'Hara

          High value, high quality RS150/TB28-537SH bookshelf - TARGAS NLA!
          SB13/Vifa BC25SC06 MTM DCR Galeons-SB13-MTM
          My Voxel min sub Yet-another-Voxel-build

          Tangband W6-sub

          Comment


          • #20
            Next up is the Peerless DA25BG08-06.

            https://www.parts-express.com/peerle...-ohm--264-1460

            It's built like a tank, double magnets, metal face plate.
            Same test conditions as the TB, here is the 75dB test.
            Pretty darn good, about .31 percent max 2nd order.

            Click image for larger version

Name:	DA25-2nd and 3rd HD at 75dB - .31percent max.png
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            The 85 dB tests were not as good, but so far this guy is the winner.
            About .75 percent max. It's a worry that the 3rd order HD is the same as 2nd order HD between 2Khz and 3.5Khz.

            Click image for larger version

Name:	DA25-2nd and 3rd HD at 85dB .75 percent max.png
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ID:	1348374

            I think I hear a difference - wow, it's amazing!" Ethan Winer: audio myths
            "As God is my witness I'll never be without a good pair of speakers!" Scarlett O'Hara

            High value, high quality RS150/TB28-537SH bookshelf - TARGAS NLA!
            SB13/Vifa BC25SC06 MTM DCR Galeons-SB13-MTM
            My Voxel min sub Yet-another-Voxel-build

            Tangband W6-sub

            Comment


            • #21
              So far, not as good as I was hoping, so I grabbed a B&G Neo 3 out of the stash and tested it also.

              https://www.parts-express.com/bohlen...k-cup--264-760

              over budget for sure, but it was paid for a long time ago, so now it's effectively $0

              75 dB test
              2nd order HD is 2.9 percent -- pretty darn high! at 3K, but 3rd order HD is way down.
              I may use this one. I liked the sound of it, just think it should be crossed 3rd order above 3Khz.

              I did not run a 85dB test.
              Click image for larger version

Name:	Neo3-2nd and 3rd HD at 75dB one meter.PNG
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              Here is the Neo3 result at 85 dB - not really bad at all.
              The projected Fc is about 3Khz, and 3rd order is way down at that point.
              Click image for larger version

Name:	Neo3-85dB - 2nd order - 2.0 percent - 3rd order .80 percent .PNG
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              Last edited by donradick; 10-16-2017, 06:21 AM.

              I think I hear a difference - wow, it's amazing!" Ethan Winer: audio myths
              "As God is my witness I'll never be without a good pair of speakers!" Scarlett O'Hara

              High value, high quality RS150/TB28-537SH bookshelf - TARGAS NLA!
              SB13/Vifa BC25SC06 MTM DCR Galeons-SB13-MTM
              My Voxel min sub Yet-another-Voxel-build

              Tangband W6-sub

              Comment


              • #22
                Last test for yesterday, pulled out the venerable Vifa BC25SC04-06 (yes I STILL have a pair left).

                Yikes! 3rd order HD is a straight line at 1.3 percent. Very strange.

                Click image for larger version

Name:	BC25SC-2nd and 3rd HD at 75dB - 1.3 percent 3rd order max.png
Views:	1
Size:	77.7 KB
ID:	1348381

                I think I hear a difference - wow, it's amazing!" Ethan Winer: audio myths
                "As God is my witness I'll never be without a good pair of speakers!" Scarlett O'Hara

                High value, high quality RS150/TB28-537SH bookshelf - TARGAS NLA!
                SB13/Vifa BC25SC06 MTM DCR Galeons-SB13-MTM
                My Voxel min sub Yet-another-Voxel-build

                Tangband W6-sub

                Comment


                • #23
                  I finally got the SB2TCN tweeters from (that "other" place) and they did not disappoint.

                  75dB distortion with a 3rd order crossover as before:




                  Click image for larger version

Name:	SB26TCN-75dB - 3rd order - .52 percent at 4K .PNG
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                  Results at 85dB were even better
                  2nd order is .82 percent, 3rd order is .2 percent.
                  Told my wife - "this one is 'sponge-worthy'" <grin>


                  Click image for larger version

Name:	SB26TCN-85dB - 2nd order - .82 percent - 3rd order .2 percent .PNG
Views:	1
Size:	79.3 KB
ID:	1349327

                  I think I hear a difference - wow, it's amazing!" Ethan Winer: audio myths
                  "As God is my witness I'll never be without a good pair of speakers!" Scarlett O'Hara

                  High value, high quality RS150/TB28-537SH bookshelf - TARGAS NLA!
                  SB13/Vifa BC25SC06 MTM DCR Galeons-SB13-MTM
                  My Voxel min sub Yet-another-Voxel-build

                  Tangband W6-sub

                  Comment


                  • #24
                    The final set of tests in the tweeter "shootout" was Omnimic Wavelet.

                    I expected the Neo3 to be the best, since it's a planar.
                    Quite good, but not as good as I'd hoped.

                    Click image for larger version

Name:	Neo3-Wavelet.PNG
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ID:	1349333


                    Next is the DA25 -- what a contrast!
                    I can't say that I can hear this, but I gotta trust the measurements.
                    Since the projected Fc is around 3Khz, this response is a worry, and right in a critical area for our hearing perception.
                    Click image for larger version

Name:	DA25-Wavelet.PNG
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ID:	1349334



                    SB26TCN Darn near as good as the Neo3, and better below 3K

                    Click image for larger version

Name:	SB26-Wavelet.PNG
Views:	1
Size:	121.2 KB
ID:	1349335

                    I think I hear a difference - wow, it's amazing!" Ethan Winer: audio myths
                    "As God is my witness I'll never be without a good pair of speakers!" Scarlett O'Hara

                    High value, high quality RS150/TB28-537SH bookshelf - TARGAS NLA!
                    SB13/Vifa BC25SC06 MTM DCR Galeons-SB13-MTM
                    My Voxel min sub Yet-another-Voxel-build

                    Tangband W6-sub

                    Comment


                    • #25
                      I am surprised by the da25. I did not take waterfall plots, but I can't say I've heard that distortion. The 3rd order stayed below 2nd order in each one I've tested (8-9 of them now?)
                      https://www.facebook.com/Mosaic-Audi...7373763888294/

                      Comment


                      • #26
                        looks like you've found a good tweeter (SB26STCN) to pair with the Gradient Axis 4

                        Comment


                        • #27
                          Originally posted by isaeagle4031 View Post
                          I am surprised by the da25. I did not take waterfall plots, but I can't say I've heard that distortion. The 3rd order stayed below 2nd order in each one I've tested (8-9 of them now?)
                          Eventually I had to give up my expectations and comparisons.
                          I accept that these tests may not directly compare to other tests.

                          But I think my methodology was correct.
                          Set overall level (75db or 85 db at 1 meter) with the OM short sine sweep signal.
                          Move the mike fairly close to DUT and switch to the long sine sweep signal.

                          I was also surprised by the DA25 diistortion, having used the DX25s and been very happy with those.


                          I think I hear a difference - wow, it's amazing!" Ethan Winer: audio myths
                          "As God is my witness I'll never be without a good pair of speakers!" Scarlett O'Hara

                          High value, high quality RS150/TB28-537SH bookshelf - TARGAS NLA!
                          SB13/Vifa BC25SC06 MTM DCR Galeons-SB13-MTM
                          My Voxel min sub Yet-another-Voxel-build

                          Tangband W6-sub

                          Comment


                          • #28
                            Originally posted by ceiol View Post
                            looks like you've found a good tweeter (SB26STCN) to pair with the Gradient Axis 4

                            The plan at this point is 1 pair with the SB26TCN and one pair with the Neo3 tweeters.
                            The enclosures may be truncated pyramids. That will really test my woodworking skills.


                            I think I hear a difference - wow, it's amazing!" Ethan Winer: audio myths
                            "As God is my witness I'll never be without a good pair of speakers!" Scarlett O'Hara

                            High value, high quality RS150/TB28-537SH bookshelf - TARGAS NLA!
                            SB13/Vifa BC25SC06 MTM DCR Galeons-SB13-MTM
                            My Voxel min sub Yet-another-Voxel-build

                            Tangband W6-sub

                            Comment


                            • #29
                              Do you have a waterfall plot for the BC25SC04-6?

                              Comment


                              • #30
                                Originally posted by donradick View Post


                                The plan at this point is 1 pair with the SB26TCN and one pair with the Neo3 tweeters.
                                The enclosures may be truncated pyramids. That will really test my woodworking skills.

                                Truncated pyramids with the slot port you previously mentioned? That's definitely above my skillset.

                                I'll have to adopt a design with all 90 degree angles otherwise my axis gradient drivers will be sitting in a box on the shelf for years...

                                Comment

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