Announcement

Collapse
No announcement yet.

MLTL for Vifa P17WJ help

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • MLTL for Vifa P17WJ help

    Hi I found the following comment from a poster in a DIY audio forum
    It looks a very interesting design.
    Just a question ,should I use any sort of stuffing?
    TIA

    "They have to be large to go low with any authority. A ML-TL is much more flexible though. Here's a proven design that's slightly <25L for a single P17 tuned to ~Fs using these averaged measured specs of several units:

    Fs = 46.17Hz
    Vas = 21.93L (0.774ft^3)
    Sd = 135.62cm^2 (21.021"^2)
    Qes = 0.6
    Qms = 1.28
    Qts = 0.40851
    Re = 5.83ohms
    Le = 0.92mH
    BL = 6.35 N/A
    Cms = 8.3067e-04mm/N
    Mms = 0.0143051Kg

    L = 30.22"
    pipe area (CSA) = 46.017"^2
    vent = 2.5" dia x 4.5" long near/at the bottom
    driver down from top 11.53"

  • #2
    Re: MLTL for Vifa P17WJ help

    Using the T/S values and cabinent dimensions as quoted below, I modeled this ML-TL. I modeled with ~6 ounces of stuffing uniformaly distributed at a density of 0.75 lb/cu.ft. in the top 18" of the enclosure. I modeled with the port's center located 2" above the bottom. So, yes you do need to use stuffing and it can be normal polyester "pillow stuffing" (Polyfil from Walmart) or Acousta Stuf. I've attached the resulting system SPL vs. Frequency response graph.
    Paul

    Originally posted by abn1701 View Post
    Hi I found the following comment from a poster in a DIY audio forum
    It looks a very interesting design.
    Just a question ,should I use any sort of stuffing?
    TIA

    "They have to be large to go low with any authority. A ML-TL is much more flexible though. Here's a proven design that's slightly <25L for a single P17 tuned to ~Fs using these averaged measured specs of several units:

    Fs = 46.17Hz
    Vas = 21.93L (0.774ft^3)
    Sd = 135.62cm^2 (21.021"^2)
    Qes = 0.6
    Qms = 1.28
    Qts = 0.40851
    Re = 5.83ohms
    Le = 0.92mH
    BL = 6.35 N/A
    Cms = 8.3067e-04mm/N
    Mms = 0.0143051Kg

    L = 30.22"
    pipe area (CSA) = 46.017"^2
    vent = 2.5" dia x 4.5" long near/at the bottom
    driver down from top 11.53"
    Attached Files

    Comment


    • #3
      Re: MLTL for Vifa P17WJ help

      Thanks a lot Paul.

      Comment


      • #4
        Re: MLTL for Vifa P17WJ help

        Hey Guys, what driver is that and do you have a link to the thread?

        Cheers!
        Marty

        Comment


        • #5
          Re: MLTL for Vifa P17WJ help

          Hi! Marty
          this is the link

          http://www.diyaudio.com/forums/multi...-speakers.html


          Cheers

          Comment


          • #6
            Re: MLTL for Vifa P17WJ help

            You're welcome and I hope it works out to your satisfaction.
            Paul

            Originally posted by abn1701 View Post
            Thanks a lot Paul.

            Comment


            • #7
              Re: MLTL for Vifa P17WJ help

              Originally posted by Paul K. View Post
              You're welcome and I hope it works out to your satisfaction.
              Paul
              Thread Jack----

              So my ML-QWTs that you designed last summer/fall are first on the list to completed this spring, things got hectic and never got around to building them. Maybe by the next DIY meet I'll have them up and running. Just wanted to let you know your efforts aren't in vain.
              ----------------------------------
              Gear:
              Samsung PN50A650
              Yamaha RX-V2500
              Hafler DH-200
              AC130MKII/BG NEO3PDR Two-Ways
              RS390HF-4 w/ HPSA500

              Comment


              • #8
                Re: MLTL for Vifa P17WJ help

                Good to hear and I look forward to listening to them.
                Paul

                Originally posted by JustinG View Post
                Thread Jack----

                So my ML-QWTs that you designed last summer/fall are first on the list to completed this spring, things got hectic and never got around to building them. Maybe by the next DIY meet I'll have them up and running. Just wanted to let you know your efforts aren't in vain.

                Comment


                • #9
                  Re: MLTL for Vifa P17WJ help

                  Originally posted by Paul K. View Post
                  Using the T/S values and cabinent dimensions as quoted below, I modeled this ML-TL. I modeled with ~6 ounces of stuffing uniformaly distributed at a density of 0.75 lb/cu.ft. in the top 18" of the enclosure. I modeled with the port's center located 2" above the bottom. So, yes you do need to use stuffing and it can be normal polyester "pillow stuffing" (Polyfil from Walmart) or Acousta Stuf. I've attached the resulting system SPL vs. Frequency response graph.
                  Paul
                  Hi Paul,

                  I have 10 of these units in my parts depot....so I sent you an email for details. But I forgot to ask one other thing. Could these be modeled in a smaller "bookshelf" type TL...such as what PMC uses...what would be the result? Something around 15-16" tall, 8.5" wide, and ?? inches deep...outside dimensions using 3/4" materials. Thanks,

                  John

                  John
                  If it doesn't fit right the first time, you obviously need to use a larger hammer. :p

                  Comment


                  • #10
                    Re: MLTL for Vifa P17WJ help

                    John, I sent you a direct email before reading this and mentioned the cabinet could be configured as a stand-mount by folding the line once. Your suggested outside width and height are spot on and the outside depth would end up around 14.5".
                    Paul

                    Originally posted by johnnail View Post
                    Hi Paul,

                    I have 10 of these units in my parts depot....so I sent you an email for details. But I forgot to ask one other thing. Could these be modeled in a smaller "bookshelf" type TL...such as what PMC uses...what would be the result? Something around 15-16" tall, 8.5" wide, and ?? inches deep...outside dimensions using 3/4" materials. Thanks,

                    John

                    John

                    Comment

                    Working...
                    X