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Please help with FRD and ZME files.

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  • Please help with FRD and ZME files.

    Hello, I'm new to the speaker world, Please, is it possible to generate the FRD and ZMA files from this images that can be used for XO design? The speaker is a Jbl Selenium 12" Pw7, This images are from the manufacture. Isn't this images missing some numbers to the right of them? Can anyone help me to get them please? ​I really appreciated, thank you. Click image for larger version

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  • #2
    You could download (user) Fprawn's "FPTrace" software, or just use these:
    NOTE: traced files (like these) NEED to have minphase files generated so you can get "phase" data.
    Traced files have all zeros in the phase angle field (the 3rd one).



    • #3
      Chris Roemers, thank you very very much for your help. About your NOTE: I don't understand much, but I need to learn so much more.
      My speaker box I try to tune it to 43 hz. In the mind time I have come up with this for my Xover, What should I change in your opinion. Thank you again and again..
      Click image for larger version

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      • #4
        I don't think you've modeled in any Baffle-step Compensation (BSC). EYE am cutting that tweeter by about -25dB !

        Looking at YOUR schemo, I'd change your 4 component values:
        from 8uF to only 2uF, from a 0.28mH coil UP to a (large) 3.0mH, and on your "L-pad" I went with 25ohms SR (series resistor) instead of 5.6, and for the PR I used 2ohms (instead of 3.3). This should necessitate a pretty hefty parallel resistor (the 2 ohmer), like maybe 20watts?
        I ALSO added 2 (additional) ohms of (series) resistance out in front (to the left) of your initial series cap.
        Also, where the 2 drivers' FR curves cross, you want them to SUM (so, HIGHer output, not lower like YOUR graph shows). You can change the polarity of the tweeter (usually) to fix that issue.

        For the woofer, I just used a single (series) coil, a "low DCR" (iron core) 4.0mH, and used a "Zobel" across the woofer.
        To sim that, just change your 6.6uF cap to a 12uF, AND (BELOW) under that cap I added a 10ohm resistor between the cap and ground.

        This crosses "around" 2kHz (not sure if your drivers will be happy with that?) and has a (low) system sensitivity of about 86dB (but with full BSC).
        The impedance remains above 8ohms across the board.


        • #5
          It would be helpful to understand what sort of speaker you are trying to design. Maybe its obvious from your driver choices - I assume you are looking at making a Pro Sound speaker (party/dj)? I would further assume then that ability to go loud is the preference over all else?

          I only ask because I've seen people try and make living room hifi speakers with these sort of drivers.

          The compression driver's final response pattern (and therefore the crossover and how it integrates with the woofer) is all dictated by what size/shape horn you load it into. Are you working with a tweeter measurement that's from a given horn?

          The woofer itself - I don't think it was ever intended to be used in the midrange - its going to be a challenge to pair with the tweeter. Professional 12 inch woofers like this should easily achieve 90db sensitivity in a final product - but the response pattern on this one is so poor through the midrange, that (particularly in a two way design) you are likely to end up in the mid 80's instead which sort of diminishes the purpose of running with pro drivers in the first place. If you already own the driver - maybe just something to consider in the future. If you don't already own it - look around for a better alternative for a two way design.
          Constructions: Dayton+SB 2-Way v1 | Dayton+SB 2-Way v2 | Fabios (SB Monitors)
          Refurbs: KLH 2 | Rega Ela Mk1


          • #6
            Hi Chris and DeZZar, Thanks again for all your input / help, I am in Argentina, perhaps I should have started telling what I want to accomplish with this speaker. DeZZar, you were right on. I wanted a baffle that I can move around to ( play backing tracks, party/dj). and sound loud and clear. I build a box of 2.3 cubic feet ( manufacture subjection ) to this mid/woofer JBL Selenium 12Pw7 ( 8 ohms, 40 to 4500 HZ , 95 SPL) and for the mids/higths a compression driver Selenium D220 Ti ( 8 ohms, 1000 to 20000, 109 SPL) screwed to the Selenium Horn HC 23-25. They are all Brazilians parts. Unfortunately I don't have a Part Express ready available here. Then I found you guys and went crazy, trying to make this sound as good as possible building a Xover for it.
            I have no Idea what a Baffle-step Compensation is. Click image for larger version

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ID:	1497860 Chris, I model what you toll me and come up with this, but I don't know how to build a "Zobel " don't know what values parts to use. What a big difference yours made in the plot! My problem with this are the coils, my bigger coil is 1.9 mH ( (iron core 16 AWG ) -1.0 mH ( ( iron core 16 AWG ) - 0.52 ( air core 16 AWG ). About switching the polarity of the tweeter, all I have to do is switch the wire in the driver? Is there a way to make this box sound loud and descent with parts (COILS) in hand? Thank you so much.

            To answer DeZZar comments/questions, just like you assume/ said, I want an speaker box loud and clear. You asked, " Are you working with a tweeter measurement that's from a given horn?" I toke the measurements from Selenium Website, "RESPONSE AND IMPEDANCE CURVES W/ HL14-25 horn IN ANECHOIC CHAMBER, 1 W / 1 m. Yes, Unfortunately I know is not the same Horn as mine. My woofer achieve 95 sensitivity according to Selenium web. And yes, I did purchased the drivers already. I wish I have found you guys before my purchased. Ho well.... ​