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CX120-8 4" measurement

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  • CX120-8 4" measurement

    Help! frequency response using Omni Mic on a pair of CX120-8 4" drivers show a dip from 1.8k--8k on both drivers. Could this be the Mic or a problem with the drivers ? Measurement taken in a large room, Mic 28" from driver and 44" above the floor. Click image for larger version

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  • #2
    That's a coaxial driver, how did you deal with the woofer and tweeter, crossover?

    Taking a guess, you've just hooked up the woofer and tweeter together, perhaps with a simple cap on the tweeter. Without a proper crossover the tweeter and woofer won't sum properly and can cause all kinds of odd response in that range.
    Electronics engineer, woofer enthusiast, and musician.
    Wogg Music


    • #3
      OOps, the post was a bit misleading. This was my FRD file for the woofer only. The dip was in the low frequency measurement, woofer only. I used the drivers in two different builds, one ported and a t-line. My crossover using PCD7 was second order elipticle filter on the woofer, and a third order butterworth on the tweeter. The crossover point was 4800 hz. (Not bad)


      • #4
        Ahh... you're way better off than I anticipated. Also, I don't have any more help That does seem quite different than the manufacture spec graph.
        Electronics engineer, woofer enthusiast, and musician.
        Wogg Music


        • #5
          It looks similar to me, but the PE measurements are infinite baffle and yours have a baffle step that you have not compensated for. Take out your baffle step and you end up with the same peaks at roughly 1800 and 8000 hz.

          The PEDS 2.1 mini system
          My A7 Project - another small desktop speaker
          The B3 Hybrid Dipole - thread incomplete and outdated