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  • No compromise center channel.

    I don't know exactly know the best way to go about it, but here is some ideas.
    My 2 trains of thought, 1 no concern for matching voicing to "mains"
    because a well designed speaker, is a well designed speaker,
    or 2 If using multiple tweeters, just the mid bass and tweet the same
    as mains in type only.

    Coaxial (the obvious first thing that comes to mind.)

    Using like 5 robust tweets like the RST28 for a very low Fc.
    (maybe in a slightly curved array)

    Using a wide rectangle or elliptical guide or even horn for low Fc.

    Horizontal line array like design either with full range or tweet on top
    with very small high quality drivers.

    Guess xmax's age.

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

  • #2
    I've seen some horizontal curved CBT arrays for center channel.

    What do you think a center channel's job is? By most definitions, it's a speaker with wide horizontal dispersion and low distortion in the speech range; not very specific parameters. I'd argue for localization that a small centrally located HF unit would be best, probably a mid in a waveguide of some sort.

    Comment


    • #3
      Within reason, any suggestions I will try to build and measure and post FRD and ZMA.
      This will be restricted to a removable center baffle 24" or less wide.
      Or in removable 24" or less sections, (my CNC limit)
      Last edited by xmax; 01-02-2019, 08:08 PM. Reason: Meat sweats.
      Guess xmax's age.

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

      Comment


      • #4
        "a speaker with wide horizontal dispersion and low distortion in the speech range"

        "a small centrally located HF unit would be best, probably a mid in a waveguide of some sort."

        This sounds good to me.
        Guess xmax's age.

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

        Comment


        • #5
          For a cost/size no object design, it's not very difficult. Just use a really good L/R speaker. I think the task of making a really high end CC which is only 8" tall, or fits in an IKEA BESTA entertainment unit, is a much more interesting task.

          The one approach I haven't modeled is the W (MTM) W layout, with a vertical MTM in the middle of two-four woofers.

          In my current project, I found that even with relatively small woofers (150mm) spaced pretty close (only an rs100p between them) you need a really low crossover point to get smooth power response and wide dispersion through the midrange. If you were to use smaller mids, you could bring the woofers closer, but they would still need to go down to 300hz or so. I like a crossover point of under 300hz, which is not easy to achieve with passive components (many compromised involved.)

          Click image for larger version

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          This version has the W/M crossover at around 400hz LR2, and even with the shallow slope and low crossover point I'm still getting a pinch point at 700hz.

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          • #6
            I was thinking more like 6" tall max.
            Guess xmax's age.

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

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            • #7
              "In my current project, I found that even with relatively small woofers (150mm) spaced pretty close (only an rs100p between them) you need a really low crossover point to get smooth power response and wide dispersion through the midrange. If you were to use smaller mids, you could bring the woofers closer, but they would still need to go down to 300hz or so. I like a crossover point of under 300hz, which is not easy to achieve with passive components (many compromised involved.)"

              Would this be avoidable if we stuck with MTM or MMTMM 2.5 way?
              Guess xmax's age.

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

              Comment


              • #8
                One of my first thoughts was MM.MTTTM.MM.
                Guess xmax's age.

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

                Comment


                • #9
                  Or even MM.MT.T.TM.MM (periods for .5 way XO)
                  Guess xmax's age.

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

                  Comment


                  • #10
                    For theatre centre channel, simply look at what your favourite theatre does and take those ideas home. What you can do for a great HT setup is to simply make the centre channel the same speaker as L/R channels, best voicing integration will be had that way. You can make them big, like maybe a 2-way speaker with 12" pro audio midbass and SEOS 12 waveguide with a nice CD, build a faux wall, just some framing out 2-3ft from the wall, install an acoustically transparent screen over the framing, and install black acoustically transparent fabric over the rest. In this type of installation you don't even have to spend all that time finishing the speakers, as they will be hidden behind the theatre screen. Install the black fabric with velcro so you can service the equipment easily.
                    "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

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                    • #11
                      So you're trying to get a lot of output with all these midwoofers? Then the issue is finding a tweeter which can keep up. Also as I've found, the mtm on its side just doesn't give good dispersion under the best circumstances.

                      Using .5 ways on the sides is sensible but it's that little array in the middle that's tricky. I needed a mid which was small and played low and loud.

                      Honestly a passive cbt array would probably be best if you want big time output and super smooth dispersion in a shallow cabinet. One of those epique arrays basically.

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                      • #12
                        Oh and check out this cheap jbl

                        https://www.jbl.com/STUDIO+520CBK.html

                        Woofer baffle slopes into a horizontal waveguide for some kind of small compression driver. A high end version of this could be really nice.

                        Comment


                        • #13
                          Originally posted by dcibel View Post
                          For theatre centre channel, simply look at what your favourite theatre does and take those ideas home. What you can do for a great HT setup is to simply make the centre channel the same speaker as L/R channels, best voicing integration will be had that way. You can make them big, like maybe a 2-way speaker with 12" pro audio midbass and SEOS 12 waveguide with a nice CD, build a faux wall, just some framing out 2-3ft from the wall, install an acoustically transparent screen over the framing, and install black acoustically transparent fabric over the rest. In this type of installation you don't even have to spend all that time finishing the speakers, as they will be hidden behind the theatre screen. Install the black fabric with velcro so you can service the equipment easily.
                          This is a excellent suggestion for projector style rooms, one step up use high output studio
                          monitors in place of pro-sound, perhaps the type your favorite film was mixed with.
                          For everyone else scroll down.
                          Guess xmax's age.

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

                          Comment


                          • #14
                            Originally posted by civit View Post
                            Oh and check out this cheap jbl

                            https://www.jbl.com/STUDIO+520CBK.html

                            Woofer baffle slopes into a horizontal waveguide for some kind of small compression driver. A high end version of this could be really nice.
                            WOW. Thanks, my horn concept wasn't as pipe dreamy as I thought. So this helps for inspiration the DIY
                            types.
                            Guess xmax's age.

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

                            Comment


                            • #15
                              Originally posted by civit View Post
                              So you're trying to get a lot of output with all these midwoofers? Then the issue is finding a tweeter which can keep up. Also as I've found, the mtm on its side just doesn't give good dispersion under the best circumstances.

                              Using .5 ways on the sides is sensible but it's that little array in the middle that's tricky. I needed a mid which was small and played low and loud.

                              Honestly a passive cbt array would probably be best if you want big time output and super smooth dispersion in a shallow cabinet. One of those epique arrays basically.
                              I should have specified MTM arrangements that are designed to avoid comb filtering and such.
                              Guess xmax's age.

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

                              Comment

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