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help needed with layout of second order series crossover

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  • help needed with layout of second order series crossover

    Hi Guys,

    A couple of weeks ago I decided to build the Mercurys, a well regarded economical 2 way. I ordered and have received all the parts, but upon looking at the crossover am completely baffled as to how to physically lay it out. The diagram does not even show any connection to the - terminal of the tweeter. I didn't realize when I ordered the components what I was getting into,but am hoping that with some explanation and coaching I'll be able to build a working crossover. I will try to post a link to the only crossover diagram that I am aware of here.http://techtalk.parts-express.com/fo...32253-Mercury=

    Cheers,

    Jay

  • #2
    On the circuit, the leg above the tweeter goes to the tweeter positive and the bottom to the negative.
    https://www.facebook.com/Mosaic-Audi...7373763888294/

    Comment


    • #3
      Dr. Jay-
      Well- a series xover is a different bird. You're used to looking at parallel networks, and this just is not that.

      Just post a photo of what you think is right, and we'll confirm it or inform what needs to change.

      That help?
      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


      • #4
        Yup (as has been stated - just to reword it), the "odd" thing about that diag. is the tweeter. It SHOULD look like the woofer below it, w/TWO leads exiting to the left (instead of 1), with the bottom (-) going down (toward the woofer) and the upper one (+) going up (toward the resistor & cap).

        Comment


        • #5
          Just to get started on figuring this out schematically, does the negative lead of the woofer go back to an un-labled output of the amp on the left side of the diagram which would ordinarily be noted with a - sign? Also, does the central horizontal line represent a wire which is connected to the components above and below it where it crosses them? I don't see any dots denoting connections so I'm confused on this aspect of the diagram too. I will certainly take advantage of Wolf's offer when I get to that stage but at this point I don't have a clear enough understanding of the diagram to lay out any components. Thanks!

          Comment


          • #6
            Originally posted by Chris Roemer View Post
            Yup (as has been stated - just to reword it), the "odd" thing about that diag. is the tweeter. It SHOULD look like the woofer below it, w/TWO leads exiting to the left (instead of 1), with the bottom (-) going down (toward the woofer) and the upper one (+) going up (toward the resistor & cap).
            No Chris, it's drawn correctly.

            EDIT: I see what you're referring to now. The circuit is drawn correctly, the symbol for the dome is sitting on one leg and you think it ought to be 2.
            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


            • #7
              Originally posted by Drjay View Post
              Just to get started on figuring this out schematically, does the negative lead of the woofer go back to an un-labled output of the amp on the left side of the diagram which would ordinarily be noted with a - sign? Also, does the central horizontal line represent a wire which is connected to the components above and below it where it crosses them? I don't see any dots denoting connections so I'm confused on this aspect of the diagram too. I will certainly take advantage of Wolf's offer when I get to that stage but at this point I don't have a clear enough understanding of the diagram to lay out any components. Thanks!
              Okay- the roller-coaster in a circle on the left is a symbol that denotes an AC supply. The + is noted on the top, and the lead out of the bottom would be the negative. This is a very common circuit emblem.
              The + labels are really all that's needed for polarity. Once you know the +, you also know what/where the - lead is connected by default.

              Any other questions?
              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


              • #8
                Wolf,
                I think what you are saying is, because it is a series crossover, for any component that has a polarity, the positive pole should be connected to the negative pole of the next component in the circuit. For example, the negative pole of the tweeter should be connected to the 3 mH inductor which is attached to the positive pole of the woofer.
                I still do not understand the horizontal line in the middle of the circuit though. Is it a wire that is connected to the components it crosses above and below it on the diagram? Thanks!

                Comment


                • #9
                  No, that's not what I'm saying at all. Even SXO's can have reverse polarity drivers depending on frequency response summation. I was just saying that the + denotes the positive terminal on the input, and each attached driver- and that's for ANY xover circuit- and that negative is logically the other side of each. This does not mean it's +-+-+-.

                  The wire in the middle is the junction that makes this a SXO in the first place. It is essentially 6 connections at one junction, easier drawn as a wire. All wires crossing in the schematic are electrically connected.

                  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


                  • #10
                    I hope folks can be patient with my "baby steps for baby feet" needs, but before I can realistically start laying out parts on the 4"X5" board for the crossover I would like to see if my conceptualization of the actual physical layout is OK. I have drawn up what I think is right using the standard symbol for resistors, a labeled rectangular box for caps and a circle for inductors. I will start trying to figure how to physically join the components once I get the connections correctly arranged. Please forgive the rough nature of the sketch. Feedback will be much appreciated

                    Comment


                    • #11
                      Nope- like this:
                      Click image for larger version

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                      "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


                      • #12
                        Much appreciated, Ben. Looking at the original circuit diagram I can clearly see the mistake I made. Thanks to you, I'll now proceed to trying to do it with the actual components.

                        Merry Christmas,

                        Jay

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