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  • Crossover Help for 2 Way Bookshelves Project

    Hi All,

    I'm experimenting with a pair of bookshelf speakers I want to build using the following:

    Woofer: HiVi M6N 6" Aluminum/Magnesium Midbass - Part # 297-441
    Tweeter: Dayton Audio DC28F-8 1-1/8" Silk Dome Tweeter - Part # 275-070

    They seem to be a good match as far as sensitivity and power capacity, now the question is, I have a pair of manufactured crossovers that are theoretically crossed at 2.7 KHz with a 12 dB/otc filter (see Pictures), they look OK quality wise to me but what do you think?

    Is that a good crossover point?

    Would I be better with another crossover design?

    All opinions are more than welcome, I'm new

    Thanks in Advance!
    Alex

    PS: I don't want perfection since I'm not even close to be able to design anything perfect, I just want them to be good enough

  • #2
    I doubt the manufactured crossovers will be very good.

    Paul Carmody uses the HI VI M5 and Dayton ND-28 in the Swope design. If you can switch drivers, you might try to copy his design and crossover. Google Paul Carmody and you can find his website.

    My guess is 2700 is too high to cross the Hi Vi M6. It is metal driver and has breakup. Note in Swope design Paul used a crossover point around 2000 hertz and with ZX Spectrum he used a crossover point below 2000 with the Hi Vi M6.

    Have not seen many 2 way designs with the Hi Vi M6 other than the ZX Spectrum.

    The Tritrix uses the tweeter you want to use. Google "Speaker Design Works" and you can find that design.

    I cannot model crossovers, so absent someone else helping, I might use use Paul's low pass from the ZX Spectrum and use the high pass from the Tritrix design. I might increase the size of the resistor on the Tritrix design a bit.

    Good luck.

    Comment


    • #3
      That's a LOT of parts for a 2-way XO, even if it's 2nd order.

      I hunted one down on the web, and here's the (translated?) description, enjoy:

      "Should be the broad masses of fancier's strong request, is a grand launch of loudspeaker for customized divider.The introduction of a total of two division and three division of the two paragraph, it can meet the basic needs of various DIY!The divider according to the main tube tone horn curve characteristics, and the sound performance, deployment, simple circuit, no need to lift or lower a band, or modified sound, but the original to frequency, as far as possible to restore the high-fidelity music.In terms of materials is very particular about, not burned the head, indiscriminate use of tonic components.Like a soprano channel, main channel capacitor, with a MKP capacitor, so that it will not pull the hind horn tweeter, bass channel inductance, inductance Q and resistance to control was excellent, of course, inductance line diameter must be big, or bass horn can do.Wando audio crossovers may not have a first-class appearance, but have a first-class quality.Taobao sellers to individual dividers do just like a work of art, the cost spent in appearance and the surface, Wando tone is to cost in the sound.Let more fancier to witness the Wando's voice.In the purchase of horn, select the appropriate frequency divider with in order to achieve the best effect!Of course, other brands of speakers can also be based on crossover with our corresponding divider."

      Most likely the best thing you could do w/those would be to salvage all the parts off them, then test them (the coils which usually aren't marked, anyhow). That's LOTS of parts.

      Something like THIS would be much more appropriate:
      (Tweeter) high pass, 2nd order around 1.8kHz, 4-elements: 8uF series cap, 0.70mH shunt coil (to gnd), "L-pad" using 3ohms series and 8ohms parallel resistors.
      (Woofer) low pass, 2nd order (w/"notch" filter) w/a Zobel using 5-elements: a 2.0mH series coil, a 7uF shunt cap, a Zobel using 10ohms and 8uF, and a tiny 0.44uF cap "across" (in parallel with) the large (2.0mH) coil (in series w/the woofer).
      This runs 84dB w/a "full" (+6dB) of baffle-step compensation.

      Comment


      • #4
        Originally posted by michaelmoran View Post
        I doubt the manufactured crossovers will be very good.

        Paul Carmody uses the HI VI M5 and Dayton ND-28 in the Swope design. If you can switch drivers, you might try to copy his design and crossover. Google Paul Carmody and you can find his website.

        My guess is 2700 is too high to cross the Hi Vi M6. It is metal driver and has breakup. Note in Swope design Paul used a crossover point around 2000 hertz and with ZX Spectrum he used a crossover point below 2000 with the Hi Vi M6.

        Have not seen many 2 way designs with the Hi Vi M6 other than the ZX Spectrum.

        The Tritrix uses the tweeter you want to use. Google "Speaker Design Works" and you can find that design.

        I cannot model crossovers, so absent someone else helping, I might use use Paul's low pass from the ZX Spectrum and use the high pass from the Tritrix design. I might increase the size of the resistor on the Tritrix design a bit.

        Good luck.

        Thanks Michael, will definitely take a look at those!

        Comment


        • #5
          Originally posted by Chris Roemer View Post
          That's a LOT of parts for a 2-way XO, even if it's 2nd order.

          Something like THIS would be much more appropriate:
          (Tweeter) high pass, 2nd order around 1.8kHz, 4-elements: 8uF series cap, 0.70mH shunt coil (to gnd), "L-pad" using 3ohms series and 8ohms parallel resistors.
          (Woofer) low pass, 2nd order (w/"notch" filter) w/a Zobel using 5-elements: a 2.0mH series coil, a 7uF shunt cap, a Zobel using 10ohms and 8uF, and a tiny 0.44uF cap "across" (in parallel with) the large (2.0mH) coil (in series w/the woofer).
          This runs 84dB w/a "full" (+6dB) of baffle-step compensation.
          Thanks for this Chris, this is definitely way ahead of my experience to understand w/o oranges and apples and of course a diagram but I fortunately have X-Over 3 Pro software and I'd love to translate your design into it, I have already entered all drivers parameters into the software but no sure where to start because:

          When you say Second order, which specifically you mean?

          If its not too much to ask, can you elaborate more (for a newbie) the purpose of each additional circuit in this design, such as the L-Pad in the tweeter or the Zobel in the woofer, etc? Please, Please, please...

          Perhaps you know the software and there's options that will lead me to that?
          Such as Impedance Equalization, Resonance Peaks or Box Effects...

          Thanks again and I really want to learn this

          Alex

          Comment


          • #6
            I do not know much, but I will try to answer your questions.

            2nd order electric means you have a capacitor and an inductor. A low pass, for the woofer, you have an inductor in series with the woofer, and the capacitor in parallel. So the capacitor is connected to both the negative and positive leads.

            think as follows: amp- positive lead - - - - - inductor---------+ woofer
            / -
            / /
            capacitor /
            / /
            / /
            amp- negative lead--------------------------------/


            For second order electric high pass for tweeter, you have capacitor in series and inductor parallel.

            The L pad is used to reduce the sound level of the tweeter to match the woofer. The woofer loses about 6 db of sound level because of baffle step. Complex concept but the speaker front (the baffle) reinforces the sound of the tweeter, as they are higher frequency. The lower frequency base notes are longer and go around the speaker which reduces the sound coming from the woofer on the base notes by about 6db.

            The zobel for the woofer is to keep the woofers impedance the same throughout the frequency range. Normally a woofer's impedance will increase as the frequency increases. The crossover depends on matching the crossover values (the inductor and capacitor value) to the impedance. A zobel keeps the impedance the same so it is easier to match with the crossover.

            Comment


            • #7
              This Should be what Chris R was explaining. Click image for larger version

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              Comment


              • #8
                Thanks a lot again Michaelmoran and Kevintomb, this definitly helps

                Comment

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