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New FAQ - How to design without measurement gear

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  • New FAQ - How to design without measurement gear

    Listen up: this is answer to all the neophyte designers who ask, "I want to design a speaker. What measurement gear will I need to buy?" NONE! Don't buy any. Learn to design a speaker first! Measurement is a whole other can of worms; do not mess with it until you really understand speaker design.

    So here's the best step-by-step tutorial I can do of how to use mfr specs (or 3rd party measurements) to "simulate" measurements one can use in the crossover design software of their choice. Best of all, this whole process is FREE. Save your dough for drivers and MDF.

    http://sites.google.com/site/undefin...d-measurements
    Last edited by Paul Carmody; 07-31-2010, 12:48 PM.
    Isn't it about time we started answering rhetorical questions?

    Paul Carmody's DIY Audio Projects
    Twitter: @undefinition1

  • #2
    Re: New FAQ - How to design without measurement gear

    Nice write up on the FRD and ZMA file prep Paul. One thing you may want to add is how to invert the baffle step after its been applied in case someone only wants partial or no BSC in their speaker design.

    Take it easy
    Jay
    "I like Brewski's threads, they always end up being hybrid beer/speaker threads based on the name of his newest creation." - Greywarden

    Breakfast Stout - HiVi RT2 II/Aurasound NS6
    Imperial Russian Stout - Vifa DX25/Fountek FW146/(2) Fountek FW168s - Built by Fastbike
    Ruination 2.5 way - Vifa DX25/Fountek FW168
    Levitation TM
    - Vifa BC25SG15/Fountek FW168

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    • #3
      Re: New FAQ - How to design without measurement gear

      Have bookmarked for a good study in the AM. Thanks!
      "Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy." --Winston Churchill

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      • #4
        Re: New FAQ - How to design without measurement gear

        Good primer! At least they can create their own files from that. It's also decent enough and not too nitty gritty to where they lose interest.

        Well said!
        Wolf
        "Wolf, you shall now be known as "King of the Zip ties." -Pete00t
        "Wolf and speakers equivalent to Picasso and 'Blue'" -dantheman
        "He is a true ambassador for this forum and speaker DIY in general." -Ed Froste
        "We're all in this together, so keep your stick on the ice!" - Red Green aka Steve Smith

        *InDIYana event website*

        Photobucket pages:
        https://app.photobucket.com/u/wolf_teeth_speaker

        My blog/writeups/thoughts here at PE:
        http://techtalk.parts-express.com/blog.php?u=4102

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        • #5
          Re: New FAQ - How to design without measurement gear

          Paul,
          Wonderful job! I can almost follow it. I appreciate your efforts so much that I am going to name the first speaker that I design the "Carmody". This also lessens my fear of people from Chicago tremendously. Thank you.
          Howard

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          • #6
            Re: New FAQ - How to design without measurement gear

            I may learn how to do this yet!!!I have just read this one time and already things make a little more sense to me. This one is in "My Really Must Read and Study" list. Your talent for writing so I can begin to understand, and want to learn more is a gift.
            Thank You "Muchly"
            cuggie
            "What's Time To A Pig?"

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            • #7
              Re: New FAQ - How to design without measurement gear

              very nice paul. thankyou.
              " To me, the soundstage presentation is more about phase and distortion and less about size. However, when you talk about bass extension, there's no replacement for displacement". Tyger23. 4.2015

              Quote Originally Posted by hongrn. Oct 2014
              Do you realize that being an American is like winning the biggest jackpot ever??

              http://www.midwestaudioclub.com/spot...owell-simpson/
              http://s413.photobucket.com/albums/pp216/arlis/

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              • #8
                Re: New FAQ - How to design without measurement gear

                Originally posted by Brewski View Post
                Nice write up on the FRD and ZMA file prep Paul. One thing you may want to add is how to invert the baffle step after its been applied in case someone only wants partial or no BSC in their speaker design.
                Ah! but that's where the whole "learning process" happens when one experiments with the baffle diffraction simulator.
                Isn't it about time we started answering rhetorical questions?

                Paul Carmody's DIY Audio Projects
                Twitter: @undefinition1

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                • #9
                  Re: New FAQ - How to design without measurement gear

                  This is another excellently written tutorial, but having seen your other beginner's faq's that's not surprising. I have a couple of small notes regarding steps 3 and 5, since in a small percentage of cases you could end up with an unsuccessful design, but otherwise, this looks like a very valuable resource for beginners.

                  Step 3 - I would not agree that WinISD should be included in any list of easiest, fastest, most accurate box simulators, as it fails on all 3 counts. In the case of tall boxes (MLTL) or long ports, WinISD comes up far short and can be incredibly inaccurate. A simulator capable of predicting box and port resonances like Hornresp or MJK's Mathcad worksheets (preferred for this job) are far more accurate - and Hornresp is far faster and easier than WinISD too. Using such an advanced program as these makes Step 4 redundant, as it's already been done as part of Step 3.

                  Step 5 - In the cases where box and/or port resonances cause problems beyond the scope of WinISD, Response Modeller is no better equipped to deal with them. In these cases, the only way to bypass this issue is to create .frd and .zma from the program used in Step 3 and import them into Response Modeller, and then continue with Step 6.

                  These nitpicks will only affect a small percentage of cases but could result in a great deal of disappointment and no option to fix the situation besides starting again.

                  I'm not sure if a link would be appropriate, but I would suggest to beginner's that Wolf's 2 crossover blogs would be a natural next "must read" for the beginner who isn't aware of them, since it takes up where this resource leaves off.

                  Overall, good job.
                  Don't even try
                  to sort out the lies
                  it's worse to try to understand.

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                  • #10

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                    • #11
                      Re: New FAQ - How to design without measurement gear

                      Very cool Paul, I'll be using this tutorial next time so I can maybe design my own.
                      Thank You.:D
                      Dan

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                      • #12
                        Re: New FAQ - How to design without measurement gear

                        Originally posted by whatatrip View Post
                        Shouldn't a couple of those frd extensions be zma extensions?
                        Yes- you are correct.
                        Later,
                        Wolf
                        "Wolf, you shall now be known as "King of the Zip ties." -Pete00t
                        "Wolf and speakers equivalent to Picasso and 'Blue'" -dantheman
                        "He is a true ambassador for this forum and speaker DIY in general." -Ed Froste
                        "We're all in this together, so keep your stick on the ice!" - Red Green aka Steve Smith

                        *InDIYana event website*

                        Photobucket pages:
                        https://app.photobucket.com/u/wolf_teeth_speaker

                        My blog/writeups/thoughts here at PE:
                        http://techtalk.parts-express.com/blog.php?u=4102

                        Comment


                        • #13
                          Re: New FAQ - How to design without measurement gear

                          Nice Job, Paul
                          Click here for Jeff Bagby's Loudspeaker Design Software

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                          • #14
                            Re: New FAQ - How to design without measurement gear

                            Wish this was around 10 months ago. You have definitely made it easier for people to get adjusted to the hobby. Kudos to you Paul.

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                            • #15
                              Re: New FAQ - How to design without measurement gear

                              Way to go Paul!

                              Before I measured, and I still measure very little, I would set myself up with an L-pad on the tweeter with cap over the series resistor to fine tune voicing. Small changes in these components can make a big sonic difference, and it is easy for a beginner to play with and see the changes in PCD.

                              I would also use mids that needed a comp series resistor in a 3-way and found it easy to fine tine the mids with small adjustments. The just have to watch the impedance with that one.
                              .

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