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Armadillo Center Channel - Crossover Question

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  • Armadillo Center Channel - Crossover Question

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    In the Armadillo crossover schematic, for the woofers, I can't tell how that's intended to be wired.

    Is it saying that one wire should go from the crossover to the + on the woofer, then a wire from the - to the + of the next woofer, then the ground wire from the crossover to the - terminal of the second woofer?

    Or

    Should it be a separate positive wire for each woofer from the same point on the crossover, and likewise, a separate ground?

    I'd understand it if it was drawn like this:

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    That makes more sense to my spatially challenged mind.

    Any thoughts? Thank you!!


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  • #2
    The Armadillo has two woofers in series, and is wired as you first describe, in to the plus, from the first woofer minus to the second woofer plus, and from the second minus to ground.

    The Swope has two woofers in parallel.

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    • #3
      Thanks a bunch!! So, the diagram for the armadillo is shorthand for series wiring? I'm pretty new to wiring schematics

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      • #4
        The Armadillo schematic would be more complete if it had the speaker terminals marked plus and minus. Usually, a schematic has the top terminal being plus. But, note the Swope design has the midrange and tweeter connected in reverse polarity, with the top terminal being minus.

        So, you can generally assume (ha) that if unmarked, the top is plus and all drivers are connected in standard polarity..

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        • #5
          Hello from Australia

          I have a pair of surplus 830656 Peerless drivers and the VIFAs on hand - well, you have to buy them when they're on sale, don't you - and wanted to have a bit of fun with a three way based on Bolland83's "Armadillo" centre channel. I certainly don't have the equipment or expertise to design something new.

          However, I only have two of the 830657s: could a crossover or design guru please let me know what changes I would need to make to the above crossover in order to use just one woofer?

          I've tried in Xsim but I can't upload the screenshot at the moment, and it looks like deleting one woofer results in 3dB bass loss, would that be right?

          Thank you very much!

          Geoff

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          • #6
            Number one: Bolland83 built that speaker. Expertly, I might add. But I designed it, and the schematic speaks for itself. Top terminal is positive for all drivers.
            You go your way, I'll go mine. I don't care if we get there on time.

            ~Pink Floyd

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            • #7
              Originally posted by Mark65 View Post
              Number one: Bolland83 built that speaker. Expertly, I might add. But I designed it, and the schematic speaks for itself. Top terminal is positive for all drivers.
              Thank you: apologies for getting you and the builder the wrong way around.

              As others have commented, the sunburst finish on those speakers is marvellous and the design looks extremely cool!

              For one woofer, would I need to increase the padding on the mid and tweeter by 3db, please? For example, would changing the resistor values do the trick: 8 ohms on the mid and 6 ohms on the tweeter L-Pad?

              Or it may be that deleting a woofer would completely mess up your good work and need a new crossover, in which case, please disregard this question.

              Cheers

              Geoff

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              • #8
                IF you've got a pair of woofers in series, the area doubles, but the impedance also doubles, and (as far as the XO goes) there's NO net gain (or loss) in sensitivity (so tweeter and/or mid padding won't be affected - in YOUR case).

                The only thing you've go to account for is to make changes to the filter so you achieve the same transfer function (at 8? ohms) as the orig. 'Dillo had (nominal 16ohms, I believe).

                I'd drop the 7mH coil down to a 3mH (iron core - to keep DCR down), push the 33uF cap up to 80uF (npe for sure), and drop the resistor down from 50 ohms to 16 ohms. It might be better to shoot for a 20w resistor there (or use a pair of 10w 30ohmers in parallel).

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                • #9
                  Originally posted by Chris Roemer View Post
                  IF you've got a pair of woofers in series, the area doubles, but the impedance also doubles, and (as far as the XO goes) there's NO net gain (or loss) in sensitivity (so tweeter and/or mid padding won't be affected - in YOUR case).

                  The only thing you've go to account for is to make changes to the filter so you achieve the same transfer function (at 8? ohms) as the orig. 'Dillo had (nominal 16ohms, I believe).

                  I'd drop the 7mH coil down to a 3mH (iron core - to keep DCR down), push the 33uF cap up to 80uF (npe for sure), and drop the resistor down from 50 ohms to 16 ohms. It might be better to shoot for a 20w resistor there (or use a pair of 10w 30ohmers in parallel).
                  Thanks Chris, that's very helpful indeed

                  Cheers

                  Geoff

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                  • #10
                    I think I might know, but I've got to ask. What is the purpose of the 50 ohm resistor, and is it safe to do that?

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