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fdieck "sounded like music not loudspeakers !"

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  • #16
    Originally posted by fpitas View Post
    ... It really helps to know the DI of the horn vs frequency, to get things sorted out.
    It is an essential element in large Pro Sound applications; such information in the basis of the CFL database - "The CLF (Common Loudspeaker Format) Group was formed for the purpose of defining and maintaining a single, open file format that loudspeaker manufacturers could use to supply data to end users in the professional sound and acoustics community."
    A Horn exceeding a 3 octave bandwidth has always presented "issues".
    "Not a Speaker Designer - Not even on the Internet"
    “Pride is your greatest enemy, humility is your greatest friend.”
    "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

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    • #17
      Originally posted by Sydney View Post
      It is an essential element in large Pro Sound applications; such information in the basis of the CFL database - "The CLF (Common Loudspeaker Format) Group was formed for the purpose of defining and maintaining a single, open file format that loudspeaker manufacturers could use to supply data to end users in the professional sound and acoustics community."
      A Horn exceeding a 3 octave bandwidth has always presented "issues".
      Lucky for me, Smith, Keele and Eargle from JBL measured the Altec 511 and plotted extensive data in their paper, "Improvements In Monitor Loudspeaker Systems".

      Click image for larger version

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      Francis

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      • #18
        Originally posted by dcibel View Post
        *Here's a plot where I did just that. Black is the on-axis, and red is the weighted average. As you can see I have some excess energy in the 2-4kHz range.

        Click image for larger version Name:	weighted average.png Views:	1 Size:	14.1 KB ID:	1375107
        *
        Help me understand this. The 2-4 Khz seems to overlap exactly, so why do you say this is a region of excessive energy?

        Comment


        • #19
          Originally posted by fpitas View Post
          ...Lucky for me,...
          More like attention to detail.
          Anecdotally - the difference between the cheapest horns and the better ( albeit more expensive ) horns is huge.
          "Not a Speaker Designer - Not even on the Internet"
          “Pride is your greatest enemy, humility is your greatest friend.”
          "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

          Comment


          • #20
            On the subject of "sounding like music, not a loudspeaker", I find a slight roll of frequency response appeals to my sense of realism; about 1/2 dB/octave from 200Hz to 10kHz.
            Francis

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            • #21
              Originally posted by skatz View Post

              Help me understand this. The 2-4 Khz seems to overlap exactly, so why do you say this is a region of excessive energy?
              The black trace is the on-axis response, and the red trace is a weighted average of the on and off-axis response. If the speaker had a constant directivity, you would see a constant slope of the red trace, but we do not, the red trace clearly has a lump around 2-4kHz. A constant slope would indicate a consistent attenuation of all frequencies as you move off-axis. Since the red trace actually overlaps the black, it can be assumed that the amplitude in this frequency rance does not decrease at all off-axis, it is a "wide dispersion" range, hence the excess energy.

              If we look closer at a directivity plot, in fact the speaker does attenuate at the extreme axis, but at the 15-30 degree range it actually increases in output a bit over the on-axis response.
              Click image for larger version

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              *
              "I just use off the shelf textbook filters designed for a resistor of 8 ohms with
              exactly a Fc 3K for both drivers, anybody can do it." -Xmax

              Comment


              • #22
                Originally posted by fpitas View Post

                Lucky for me, Smith, Keele and Eargle from JBL measured the Altec 511 and plotted extensive data in their paper, "Improvements In Monitor Loudspeaker Systems".

                Click image for larger version  Name:	Altec 511B Polar.png Views:	1 Size:	485.5 KB ID:	1375164
                I rebuilt some A7s with a heavily damped 511 using a Faital Pro HF10AK actively crossed at 1K with a passive LC and they sound fantastic.
                They are currently being used as playback and echo in the live room at RCA studio A.
                On the cover of Mix magazine this month. Along with several other mentions of my monitors.*


                Also the THX standard often used in recording studios and automobiles is a 10dB tilt from 100 to 10K!* *
                or something like that.*
                Guess xmax's age.

                My guess: 15. His grammar is passable. His trolling is good.

                Comment


                • #23
                  Originally posted by xmax View Post

                  I rebuilt some A7s with a heavily damped 511 using a Faital Pro HF10AK actively crossed at 1K with a passive LC and they sound fantastic.
                  They are currently being used as playback and echo in the live room at RCA studio A.
                  On the cover of Mix magazine this month. Along with several other mentions of my monitors.*


                  Also the THX standard often used in recording studios and automobiles is a 10dB tilt from 100 to 10K!* *
                  or something like that.*
                  Yeah, I damped mine too; cut the vanes and put a bead of 3M 5200 between them, filled the bells with polyurethane, and coated the outside with polyurethane. I have TAD TD-2002s on mine. The imaging and realism are pretty darn good for a horn from 1953...
                  Francis

                  Comment


                  • #24
                    Originally posted by fpitas View Post

                    Yeah, I damped mine too; cut the vanes and put a bead of 3M 5200 between them, filled the bells with polyurethane, and coated the outside with polyurethane. I have TAD TD-2002s on mine. The imaging and realism are pretty darn good for a horn from 1953...
                    I bet they sound fantastic! I'm working with some TAD 2002 currently.*
                    Guess xmax's age.

                    My guess: 15. His grammar is passable. His trolling is good.

                    Comment


                    • #25
                      Originally posted by skatz View Post

                      So, which ones are those?
                      For me, usually a paper coned mid bass driver with tight bass, a minimal breakup peak, and good extension into the midrange. They cover a significant percentage of music all by themselves. Once I find that, the rest is much easier.

                      Comment


                      • #26
                        Here's a set of plots that show the behavior of an 8" 2-way with a 8.5" diameter waveguide, 2" deep with a circular profile crossed at 1KHz.
                        On axis first.
                        The off axis response is exceedingly uniform, and the in-room sound was immersive.

                        Click image for larger version

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                        Click image for larger version

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                        R = h/(2*pi*m*c) and don't you forget it! || Periodic Table as redrawn by Marshall Freerks and Ignatius Schumacher || King Crimson Radio

                        Byzantium Project & Build Thread || MiniByzy Build Thread || 3 x Peerless 850439 HDS 3-way || 8" 2-way - RS28A/B&C8BG51


                        95% of Climate Models Agree: The Observations Must be Wrong
                        "Gravitational systems are the ashes of prior electrical systems.". - Hannes Alfven, Nobel Laureate, Plasma physicist.

                        Comment


                        • #27
                          Originally posted by Pete Schumacher View Post
                          Here's a set of plots that show the behavior of an 8" 2-way with a 8.5" diameter waveguide, 2" deep with a circular profile crossed at 1KHz.
                          On axis first.
                          The off axis response is exceedingly uniform, and the in-room sound was immersive.

                          Click image for larger version

Name:	RS28F version on axis.gif
Views:	1
Size:	48.7 KB
ID:	1375245

                          Click image for larger version

Name:	rs28f version off axis.gif
Views:	1
Size:	50.4 KB
ID:	1375246
                          The directivity of the 2 drivers are probably similar too for great power response!**
                          Guess xmax's age.

                          My guess: 15. His grammar is passable. His trolling is good.

                          Comment


                          • #28
                            Originally posted by xmax View Post

                            The directivity of the 2 drivers are probably similar too for great power response!**
                            NE225W-4 and RS28F
                            R = h/(2*pi*m*c) and don't you forget it! || Periodic Table as redrawn by Marshall Freerks and Ignatius Schumacher || King Crimson Radio

                            Byzantium Project & Build Thread || MiniByzy Build Thread || 3 x Peerless 850439 HDS 3-way || 8" 2-way - RS28A/B&C8BG51


                            95% of Climate Models Agree: The Observations Must be Wrong
                            "Gravitational systems are the ashes of prior electrical systems.". - Hannes Alfven, Nobel Laureate, Plasma physicist.

                            Comment


                            • #29
                              RS 28 W/ WG of course. What mic did you use to measure?*
                              Guess xmax's age.

                              My guess: 15. His grammar is passable. His trolling is good.

                              Comment


                              • #30
                                Originally posted by xmax View Post
                                rs 28 w/ wg of course. What mic did you use to measure?*
                                ecm8000
                                R = h/(2*pi*m*c) and don't you forget it! || Periodic Table as redrawn by Marshall Freerks and Ignatius Schumacher || King Crimson Radio

                                Byzantium Project & Build Thread || MiniByzy Build Thread || 3 x Peerless 850439 HDS 3-way || 8" 2-way - RS28A/B&C8BG51


                                95% of Climate Models Agree: The Observations Must be Wrong
                                "Gravitational systems are the ashes of prior electrical systems.". - Hannes Alfven, Nobel Laureate, Plasma physicist.

                                Comment

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