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Are my phase-curves OK?

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  • Are my phase-curves OK?

    Hi,

    In the linked thread:
    http://techtalk.parts-express.com/fo...eally-that-bad

    We have learned a lot about phase and related matters in the design of speakers.

    All the things appear to me as being quite useless if one makes a mistake when extracting phase from the measured SPL data for the speakers.

    As a “sanity check”, can you look at the attached picture and say if you think that the phase-curves seem OK?

    Best regards//lasse


    Click image for larger version

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    Perry Mason talking to his dentist:

    "Do you swear to take the tooth, the whole tooth and nothing but the tooth, so help you God?"

  • #2
    The only time phase matters is when the combined shift in the vicinity of the crossover approaches 180 degrees. So long as that's not the case you're good.
    www.billfitzmaurice.com
    www.billfitzmaurice.info/forum

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    • #3
      Why does your midrange SPL stop at 10K?

      dlr
      WinPCD - Windows .NET Passive Crossover Designer

      Dave's Speaker Pages

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      • #4
        Originally posted by dlr View Post
        Why does your midrange SPL stop at 10K?

        dlr
        Actually, I don´t know.

        Will check.

        Later//lasse
        Perry Mason talking to his dentist:

        "Do you swear to take the tooth, the whole tooth and nothing but the tooth, so help you God?"

        Comment


        • #5
          Hi all,

          This is a new version of RFL-3way, this time including the woofer. (and a picture of the system under test/development)

          The responses rely on the assumption that the tweeter is one inch in front of the mid and the woofer (that can be adjusted easily as can be seen by moving the mid/tw unit)

          Best regards//lasse



          Click image for larger version

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ID:	1392912Click image for larger version

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          Perry Mason talking to his dentist:

          "Do you swear to take the tooth, the whole tooth and nothing but the tooth, so help you God?"

          Comment


          • #6
            Are you using extracted min phase for all drivers? Also - did you remember to enter a -ve Z offset on any drivers relative to the tweeter voice coil? I see from the picture your T/M box is sitting back from the woofer. so probably ok on mid / woofer voice coil offset. But check all drivers anyway from the intended listening distance in your simulation. I simulate at 2 metres for a 3 way.

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            • #7
              To get the woofer tracking better with the midrange (I'd prioritise this over mid/tweeter tracking), you want to try and smooth that hump between 500 - 1000 Hz. Try adding a resistor in series with your 44uF capacitor (this will reduce the slope) but increase the capacitor value to increase the "cut". Shunt resistors are helpful at shaping slopes and they also help increase impedance (although yours looks fine).

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              • #8
                Originally posted by Dave Bullet View Post
                Are you using extracted min phase for all drivers? Also - did you remember to enter a -ve Z offset on any drivers relative to the tweeter voice coil? I see from the picture your T/M box is sitting back from the woofer. so probably ok on mid / woofer voice coil offset. But check all drivers anyway from the intended listening distance in your simulation. I simulate at 2 metres for a 3 way.
                Hi,

                Tes, I have extracted min phase for all three drivers with info from a common microphone position/point 130 cm at tweeter height.
                I have no means of entering a listening position so I guess that the mic position is the "listener position"

                The offset is the measured/guessed delta AC for the drivers and I have chosen 1 inch for the tweeter to be in front of mid and woofer.

                Regards//lasse
                Last edited by lasse; 11-06-2018, 02:09 PM. Reason: Completing the answer
                Perry Mason talking to his dentist:

                "Do you swear to take the tooth, the whole tooth and nothing but the tooth, so help you God?"

                Comment

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