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  • Correct tweeter polarity question

    I totally get how to measure the response and get the null, when connected reversed, or no null in output if correctly connected. But my question, is there any other way to tell this, without measuring response?

    Would it show in the impedance and phase measurement?

  • #2
    I can usually hear it with a sine sweep. But depends on the null amount.

    Comment


    • #3
      Not Z, but definitely phase - that's what it IS of course. Out of phase would have the phase plots NOT lying on each other (near the Fc), but up to 180* apart.
      If I HAD to try to hear it (on a 2-way TM), I'd lay the speaker sideways and play a test tone VERY near the crossover freq. - then move my head side-to-side parallel to the baffle and listen for the image to "jump" back and forth (which it should do when OOP). If there's no jump, phase is probably pretty good.

      Note: Odd order (BW) alignments typically have the 2 drivers' phase in "quadrature" (90* apart), and reversing THOSE should have little effect.

      Comment


      • #4
        Hi Kevin,

        You could certainly hear it.

        But what is your real issue?

        Normally I first deal with this in simulation, but that requires measurement of the drivers and their acoustic offsets to be accurate.

        If your drivers + crossover aren't carefully phase matched you won't have such an obvious null and you may not be able to hear a clear improvement when trying one polarity vs. another.


        Best,

        E

        Comment


        • #5
          I don't think that you should be able to "hear" whether the polarity of a tweeter is reversed or not. That is, when listening to the tweeter on its own.
          Technically, a polarity that's 'reversed' only makes logical sense in terms of how it is connected to the other drivers, polarity wise.

          For example, if you connect all of your drivers in a loudspeaker using the reverse polarity, that would make no difference from connecting them all in a normal polarity.
          All things being equal. When you mix and match them with any regard, then you'll hear a huge difference.

          Shawn

          Comment


          • #6
            Originally posted by ErikSquires View Post
            ...You could certainly hear it. ...
            Me too

            "Not a Speaker Designer - Not even on the Internet"
            "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

            Comment


            • #7
              Originally posted by Audion
              I don't think that you should be able to "hear" whether the polarity of a tweeter is reversed or not. That is, when listening to the tweeter on its own. Technically, a polarity that's 'reversed' only makes logical sense in terms of how it is connected to the other drivers, polarity wise. For example, if you connect all of your drivers in a loudspeaker using the reverse polarity, that would make no difference from connecting them all in a normal polarity. All things being equal. When you mix and match them with any regard, then you'll hear a huge difference. Shawn
              If you have no xover this is true. When you start adding xovers with different slopes it is not so true.
              craigk

              " Voicing is often the term used for band aids to cover for initial design/planning errors " - Pallas

              Comment


              • #8
                Originally posted by craigk View Post
                If you have no xover this is true. When you start adding xovers with different slopes it is not so true.

                Is this really so? I mean, imagine if you connect everything in the proper (i.e.conventional)... perhaps, you reverse the polarity of your midrange in a three-way system as you must when using a LR2 crossover to compensate for the 180 degree phase shift, for example. Everything works fine. But, if you take all the drivers, and swap all the wires plus for minus on all of them, what's really changed?

                Isn't polarity or "phase" only meaningful when considered in terms of all the drivers in the system?

                I'm not saying that you're incorrect mind, you. But, this is how I think of these things.

                Shawn

                Comment


                • #9
                  Originally posted by Chris Roemer View Post
                  Not Z, but definitely phase - that's what it IS of course. Out of phase would have the phase plots NOT lying on each other (near the Fc), but up to 180* apart.
                  If I HAD to try to hear it (on a 2-way TM), I'd lay the speaker sideways and play a test tone VERY near the crossover freq. - then move my head side-to-side parallel to the baffle and listen for the image to "jump" back and forth (which it should do when OOP). If there's no jump, phase is probably pretty good.

                  Note: Odd order (BW) alignments typically have the 2 drivers' phase in "quadrature" (90* apart), and reversing THOSE should have little effect.


                  Kinda what I was curious to know.

                  I never purposely tried doing phase to "See" the difference, and was just wondering if anyone had.

                  SO there should be a big "jog" where it goes from -phase to +phase basically around the xover area?

                  Comment


                  • #10
                    Originally posted by Audion View Post


                    Is this really so? I mean, imagine if you connect everything in the proper (i.e.conventional)... perhaps, you reverse the polarity of your midrange in a three-way system as you must when using a LR2 crossover to compensate for the 180 degree phase shift, for example. Everything works fine. But, if you take all the drivers, and swap all the wires plus for minus on all of them, what's really changed?

                    Isn't polarity or "phase" only meaningful when considered in terms of all the drivers in the system?

                    I'm not saying that you're incorrect mind, you. But, this is how I think of these things.

                    Shawn
                    I think you might be overthinking this. Yes, if you swap the phase of all speakers in a full system (drivers and Xover) it will sound the same. But you can do a small DC voltage on them and visually see the difference.

                    I think what Kevin was asking is; are there other ways to find an incorrectly phased driver without measuring response. At least that is what I assumed So, as in your example if the mid is supposed to be out 180 and you did not install it this way, you will likely hear it.

                    Comment


                    • #11
                      Originally posted by ErikSquires View Post
                      Hi Kevin,

                      You could certainly hear it.

                      But what is your real issue?

                      Normally I first deal with this in simulation, but that requires measurement of the drivers and their acoustic offsets to be accurate.

                      If your drivers + crossover aren't carefully phase matched you won't have such an obvious null and you may not be able to hear a clear improvement when trying one polarity vs. another.


                      Best,

                      E

                      My issue? Just messing with a retail speaker for fun and realized I was not "Sure" of tweeter connection.
                      Schematic shows it 2 ways, so it is no help.

                      Then I started messing with it and found I was not able to tell if connected right or wrong, after seeing a tiny red dot for the positive.
                      Although it may have a relatively bad null and phase alignment.

                      Long story, a goodwill find!
                      I

                      Comment


                      • #12
                        Originally posted by Audion View Post


                        Is this really so? I mean, imagine if you connect everything in the proper (i.e.conventional)... perhaps, you reverse the polarity of your midrange in a three-way system as you must when using a LR2 crossover to compensate for the 180 degree phase shift, for example. Everything works fine. But, if you take all the drivers, and swap all the wires plus for minus on all of them, what's really changed?

                        Isn't polarity or "phase" only meaningful when considered in terms of all the drivers in the system?

                        I'm not saying that you're incorrect mind, you. But, this is how I think of these things.

                        Shawn
                        you are looking at everything as if it relates to absolute phase, or reversing polarity on the drivers. a crossover looks at relative phase and linear phase also. so you can be out of phase any degree and even up to the point of being out of the same cycle. a lot more to it than just swapping the plus and minus wires.
                        craigk

                        " Voicing is often the term used for band aids to cover for initial design/planning errors " - Pallas

                        Comment


                        • #13
                          Originally posted by GTPlus View Post

                          I think you might be overthinking this. Yes, if you swap the phase of all speakers in a full system (drivers and Xover) it will sound the same. But you can do a small DC voltage on them and visually see the difference.
                          Yes.

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                          • #14
                            Originally posted by Audion View Post

                            Yes.

                            [ATTACH=CONFIG]n1328920[/ATTACH]
                            but your not really changing phase, you are changing polarity, polarity and phase only work like this when it is a 2 nd order crossover.
                            craigk

                            " Voicing is often the term used for band aids to cover for initial design/planning errors " - Pallas

                            Comment


                            • #15
                              Originally posted by GTPlus View Post

                              I think you might be overthinking this. Yes, if you swap the phase of all speakers in a full system (drivers and Xover) it will sound the same. But you can do a small DC voltage on them and visually see the difference.

                              I think what Kevin was asking is; are there other ways to find an incorrectly phased driver without measuring response. At least that is what I assumed So, as in your example if the mid is supposed to be out 180 and you did not install it this way, you will likely hear it.
                              Exactly! I know how to measure it with Response, but now not totally certain I can "Hear it" in all situations. I guess not all speakers "Null" to the same extent when one or the other driver is reversed.

                              And yes, I am talking about relative polarity from a woofer to tweeter, you are correct.

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