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Tweets that cross below 2khz LR2

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  • Tweets that cross below 2khz LR2

    Other than the RS28's 🤔

  • #2
    Seas 27TBFCG. Zaph BAMTM uses it crossed at 1450 Hz.

    Comment


    • #3
      In Zaph's design contest Jay Kim crossed the SB29RDC at 2.0 KHz using LR2. Harmonic distortion plots at 90, 100 and 110 dB. There's also the SB26ADC - Troels Gravensen said "Now, I've checked my most recent tweeter tests, and I can't find any tweeter displaying such low distortion all the way down to 1 kHz." But he crossed it LR2 at 2.5 KHz in one of his speakers. YMMV.
      Last edited by ernperkins; 12-20-2016, 07:50 AM.
      "Everything is nothing without a high sound quality." (Sure Electronics)

      Comment


      • #4
        Originally posted by JimHRB View Post
        Seas 27TBFCG. Zaph BAMTM uses it crossed at 1450 Hz.
        I don't know that the BAMTM was an LR2 design though...
        Confirmed- it was LR4.
        http://www.zaphaudio.com/BAMTM.html

        LR2 below 2k is a really tall order for most tweeters.

        The TLabs N26 line is one that will. If I'm not mistaken, the SS Rev 9900, and Satori tweeters also will.

        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:
        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


        • #5
          Originally posted by Wolf View Post

          I don't know that the BAMTM was an LR2 design though...
          Confirmed- it was LR4.
          http://www.zaphaudio.com/BAMTM.html
          It's second order electrical. Cap and coil on each driver.

          Comment


          • #6
            The 27TBFC and TDFC will NOT do LR2 at 2KHz. They start rolling off on their own too early and once a filter is applied will exhibit 4th order acoustic slope too soon.

            As Wolf said, there are very few dome tweeters that can really pull off LR2 at 2KHz because it calls for natural response flat to 1KHz and lower.

            Look at the response of the Scan-Speak D2604/8320-02. That's what you need to pull off LR2 at 2KHz.




            The D3004/6600 is an exemplary tweeter for doing LR2 at 2KHz.



            The SEAS 27TDFC is not a proper candidate. Rolls off too early as you can see.

            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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            • #7
              Originally posted by JimHRB View Post

              It's second order electrical. Cap and coil on each driver.
              You are confusing the difference between acoustic summation and electrical order.

              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:
              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


              • #8
                I've crossed the Dayton RS28F at 1200 hz. Great tweeter.
                Here's 3 on-axis FR tests with 200 uF series cap, 16 uF series cap and added 0.5mH coil. 3rd HD curves at bottom.
                Attached Files
                Live in Southern N.E.? check out the CT Audio Society web site.

                Comment


                • #9
                  Originally posted by carlspeak View Post
                  I've crossed the Dayton RS28F at 1200 hz. Great tweeter.
                  Here's 3 on-axis FR tests with 200 uF series cap, 16 uF series cap and added 0.5mH coil. 3rd HD curves at bottom.
                  You didn't xover the RS28 at 1.2k/LR2 though. LR2 is the query.

                  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:
                  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


                  • #10
                    Scan D2604/833000 Used it in the Fatbellies at 1.2K, soft knee to a wall at 800. It would easily handle 2K 2LR...Though I would likely not cross ANY tweeter that low including the RS28 unless it's an 8" 2-way you are looking for.
                    .

                    Comment


                    • #11
                      Thanks! The D2604 special edition caught my eye as well, but they recommend min 2.5khz - gap height/max excursion are same as standard d2604 (and 6600)but the linear exc is less at just 0.1mm

                      Comment


                      • #12
                        I think Wavecor TW030WA11 and TW030WA12 should be able to do it.
                        I'm not deaf, I'm just not listening!

                        Comment


                        • #13
                          Originally posted by Wolf View Post

                          You didn't xover the RS28 at 1.2k/LR2 though. LR2 is the query.

                          Later,
                          Wolf
                          The combination of 16 uF cap and a parallel coil is L//R in my book, although a 1.0 mH coil would have been the more correct one for 1.2 kHz..
                          Live in Southern N.E.? check out the CT Audio Society web site.

                          Comment


                          • #14
                            Originally posted by bill poster View Post
                            Thanks! The D2604 special edition caught my eye as well, but they recommend min 2.5khz - gap height/max excursion are same as standard d2604 (and 6600)but the linear exc is less at just 0.1mm

                            The 833000 seems to have a larger chamber too, and the dual magnets. Has not let me down yet and is by a large margin my favorite affordable low-cross tweeter. The 2604SE, which I have in-house and measure amazingly well, are more remenisant of a straight DX25 variant where the 833000 is on the same platform, but the engine has been beefed up, and the fenders tubbed out for slicks....Copper cap, too, which the DX25 does not have. Comparing the two I would wager would be like one built for the drag, the other for the grand prix. Bottom line being both great performers, just need to be used in their respective venues.
                            .

                            Comment


                            • #15
                              Originally posted by carlspeak View Post
                              The combination of 16 uF cap and a parallel coil is L//R in my book, although a 1.0 mH coil would have been the more correct one for 1.2 kHz..
                              I will say your plot (green line) approximates about a 10dB/octave rolloff from 2k, -6dB at ~1.6-1.7k, which is pretty close to the target of the OP, however, I would not call it a 1.2kHz xover. You're almost -9/-10dB at 1.2k. LR dictates a -6dB at xover. I am also wondering about the HD from your filter, as you are at only -35dB from reference level at just shy of 400Hz. This being an ~LR2 rolloff that you actually do have, I'm curious at what level these were taken. If at a lower level, I can see the possibility of the RS28 becoming edgy at moderate levels.

                              I mean no disrespect, I'm just trying to make sure electrical vs acoustic rolloffs are not confused to best reply to the OP or other interested parties since this thread has been confusing the terms.

                              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:
                              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

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