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  • Mltl?

    How long would an MLTL be for tuning in the upper 20's?
    Loren Jones

    http://techtalk.parts-express.com/sh...-sound-drivers

    http://techtalk.parts-express.com/sh...for-live-sound

  • #2
    Re: Mltl?

    All is dependent on the driver.

    Comment


    • #3
      Re: Mltl?

      As an example of a MLTL with a 6.5" diameter driver consider this:

      There is a thread on the Jeff Bagby's Docere project which was the sample speaker design that Jeff discussed during the Meniscus Audio sponsored Bagby Seminar last December in Kokomo. After the seminar I designed a MLTL for the Eclipse 6520R-4 6.5" woofer sold by Meniscus. The inside dimensions of the box is 43.25" tall x 7.0" wide x 8.0" deep. The response is flat down to 30 Hz and the F3 roll off point is in the 26-27 Hz area. The port tuning is about 29 Hz with a 2.5" diameter port that is 7" long.

      As with vented boxes and MLTLs too, you are ultimately limited on the low end of the band by the Xmax of the woofer, the power level applied, power handling of the driver, etc. Hence, this isn't a subwoofer but will handle most music quite well. See the thread at:

      http://techtalk.parts-express.com/sh...ghlight=docere

      Comment


      • #4
        Re: Mltl?

        I'll read that thread and also try to read some other MLTL resources.

        I am assuming based on your mention of length, width and depth of the enclosure that the cross sectional area matters in addition to the length?

        Originally posted by Jim Griffin View Post
        As an example of a MLTL with a 6.5" diameter driver consider this:

        There is a thread on the Jeff Bagby's Docere project which was the sample speaker design that Jeff discussed during the Meniscus Audio sponsored Bagby Seminar last December in Kokomo. After the seminar I designed a MLTL for the Eclipse 6520R-4 6.5" woofer sold by Meniscus. The inside dimensions of the box is 43.25" tall x 7.0" wide x 8.0" deep. The response is flat down to 30 Hz and the F3 roll off point is in the 26-27 Hz area. The port tuning is about 29 Hz with a 2.5" diameter port that is 7" long.

        As with vented boxes and MLTLs too, you are ultimately limited on the low end of the band by the Xmax of the woofer, the power level applied, power handling of the driver, etc. Hence, this isn't a subwoofer but will handle most music quite well. See the thread at:

        http://techtalk.parts-express.com/sh...ghlight=docere
        Loren Jones

        http://techtalk.parts-express.com/sh...-sound-drivers

        http://techtalk.parts-express.com/sh...for-live-sound

        Comment


        • #5
          Re: Mltl?

          Yes the cross-sectional-area does matter in MLTLs. For this project I tried to match the external baffle width (8.5" with 0.75" thick material) that Jeff established for his stand mount design so that his crossover could be used as is. Normally, you can trade depth for width while maintaining the CSA.

          Comment


          • #6
            Re: Mltl?

            To be direct I was wondering about the feasibility of an MLTL enclosure for the Dayton ST305 in a cabinet about 15" wide and 42" to 46" tall. I need to read Martin King's pages again but I don't have math cad anyway so wouldn't be able to use his worksheets anyway.
            Loren Jones

            http://techtalk.parts-express.com/sh...-sound-drivers

            http://techtalk.parts-express.com/sh...for-live-sound

            Comment


            • #7
              Re: Mltl?

              There is no specific line length (cabinet height, most likely) that has to be used to create an ML-TL, but the longer that length is, the more its 1/4-wavelength resonant frequency contributes to the overall system tuning and the less needed from the port. Once you determine what the optimum tuning frequency is, for whatever response shape you want and with a specific cabinet height and starting cross-section dimensions, you can increase or decrease the cross-sectional area in order to achieve a desired f3, or an f3 that gives the best compromise for SPL output and driver excursion. As you change the line volume you will need to tweak the port's dimensions to maintain the optimum tuning frequency.
              Paul

              Originally posted by lorenmjones View Post
              To be direct I was wondering about the feasibility of an MLTL enclosure for the Dayton ST305 in a cabinet about 15" wide and 42" to 46" tall. I need to read Martin King's pages again but I don't have math cad anyway so wouldn't be able to use his worksheets anyway.

              Comment

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