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  • source for out-sourcing crossover design

    I read the forum daily, but really don't post as I'm trying to absorb as much as possible.

    I've enjoyed building many of the designs found here and around the web. I have an optical engineering background of sorts, but the audio world is relatively new to me.

    Among my favorites that I've built are:

    PEDS computer system by BOBinGA
    http://techtalk.parts-express.com/fo...room-or-office
    amazing how the bass boost of the 2.1 plate amp works with the Tang Band W6 sub driver

    Navyguy Kerry's Choti speakers

    Zisserson's New Horizons III

    Jeffb's Quarks with Paul C's voxel sub

    Chris Roemer's Nano Neos

    TomZ's Bantams (love the use of the PR)

    And last night I started working on the crossovers for Mark65's Dadiels.


    But I built one system that just doesn't sound right to me -- the LM1s.
    It uses good drivers:
    -Peerless 830991 woofer
    -Tymphany XT25BG60-04 tweeters
    I doubled checked the crossover designs and I'm making it exactly as the diagram shows.
    But it just doesn't sound right.

    I don't have OmniMic or any RTA, but compared to all of the other speaker designs that I've tried, these just sound way off.

    at this point, I am looking to outsource the design of the crossover to someone who has skills that would take me years to learn. I will then build the crossovers myself. It would be great if I could re-cycle any of the crossover components from the original design, but if not, no problem.

    Do you know of anyone who offers this service for a reasonable fee?

    thanks in advance



  • #2
    from last night's crossover build (Mark65's Dadiels)

    Click image for larger version

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    • #3
      Where are you located?

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      • #4
        Los Angeles

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        • #5
          Maybe someone close to where you live can help?

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          • #6
            Curtis List used to have a company that designed crossovers, mostly for pro audio, but he did DIY himself. I don't know if he is still doing it, he had a debilitating illness. I'll see if I can dig up a link to him if you wish.

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            • #7
              Here's what I found:

              https://www.linkedin.com/in/curtis-list-aa49136

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              • #8
                thank you. I will try contacting Curtis

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                • #9
                  Originally posted by ceiol View Post


                  But I built one system that just doesn't sound right to me -- the LM1s.
                  It uses good drivers:
                  -Peerless 830991 woofer
                  -Tymphany XT25BG60-04 tweeters
                  I doubled checked the crossover designs and I'm making it exactly as the diagram shows.
                  But it just doesn't sound right.

                  I don't have OmniMic or any RTA, but compared to all of the other speaker designs that I've tried, these just sound way off.

                  at this point, I am looking to outsource the design of the crossover to someone who has skills that would take me years to learn. I will then build the crossovers myself. It would be great if I could re-cycle any of the crossover components from the original design, but if not, no problem.

                  Do you know of anyone who offers this service for a reasonable fee?

                  thanks in advance

                  It's funny that you bring this up because I just mentioned in another thread a day or two ago that I would never recommend building this speaker to anyone.
                  -Kerry

                  www.pursuitofperfectsound.com

                  Comment


                  • #10
                    I threw this together quickly based on his measurements he had posted and using a nearfield merge from the woofer's published graphs. Assuming his measurements are mostly accurate, this might be a good place to start. You might have to play with some of the values a bit to see how you like it. Tweeter is in normal polarity.

                    Woofer: (first order electrical) 1.8 mH

                    Tweeter: (third order electrical with RLC impedance notch): 3 Ohm (series before crossover), 5 uF, 0.3 mH (use a resistor to get total resistance of the inductor and resistor up to 1.5 Ohm), 8 uF notch: 0.5 mH, 100 uF, 3.50 Ohms
                    Click image for larger version

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                    -Kerry

                    www.pursuitofperfectsound.com

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                    • #11
                      Originally posted by Navy Guy View Post

                      It's funny that you bring this up because I just mentioned in another thread a day or two ago that I would never recommend building this speaker to anyone.

                      For a newbie like me, the draw of that site / that design is that it is so very detailed in the documentation. To the uninformed (like me), it seems really well done... until the money is sunk in the drivers, crossovers, and dayton prebuilt boxes ($$$) and it is built. It's the most expensive build for me thus far, and the one I like the least.

                      But I'm hopeful that a revamp of the crossover can remedy the situation. If not, then I'll just scrap it and repurpose the dayton cherry cabinets for another design that has already been vetted

                      Thanks for your effort above -- looks good. What's the area that you're targeting with the notch filter?

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                      • #12
                        Originally posted by ceiol
                        For a newbie like me, the draw of that site / that design is that it is so very detailed in the documentation. To the uninformed (like me), it seems really well done... until the money is sunk in the drivers, crossovers, and dayton prebuilt boxes ($$$) and it is built. It's the most expensive build for me thus far, and the one I like the least. But I'm hopeful that a revamp of the crossover can remedy the situation. If not, then I'll just scrap it and repurpose the dayton cherry cabinets for another design that has already been vetted Thanks for your effort above -- looks good. What's the area that you're targeting with the notch filter?
                        The notch is for the impedance peak on the tweeter rather than in the frequency. It helped make things easier to shape in the crossover because of the size and location of the peak.
                        -Kerry

                        www.pursuitofperfectsound.com

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                        • #13
                          Kerry -

                          FYI for your sim - I don't know if you saw this, but he measured the acoustic offset to be 1.32 inches (0.335 m) using the DLR/Bagby method.



                          Originally posted by Navy Guy View Post
                          I threw this together quickly based on his measurements he had posted and using a nearfield merge from the woofer's published graphs. Assuming his measurements are mostly accurate, this might be a good place to start. You might have to play with some of the values a bit to see how you like it. Tweeter is in normal polarity.

                          Woofer: (first order electrical) 1.8 mH

                          Tweeter: (third order electrical with RLC impedance notch): 3 Ohm (series before crossover), 5 uF, 0.3 mH (use a resistor to get total resistance of the inductor and resistor up to 1.5 Ohm), 8 uF notch: 0.5 mH, 100 uF, 3.50 Ohms
                          [ATTACH=CONFIG]n1332282[/ATTACH]

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                          • #14
                            Originally posted by ernperkins
                            Kerry - FYI for your sim - I don't know if you saw this, but he measured the acoustic offset to be 1.32 inches (0.335 m) using the DLR/Bagby method.
                            I didn't, but he had his summed woofer/ tweeter with no crossover measurement posted. I used that and got 25mm. Strange that they would be different. By the way, the notch is in parallel with the tweeter, all components of it in series.
                            -Kerry

                            www.pursuitofperfectsound.com

                            Comment


                            • #15
                              I have a pair of those woofers! I can help you I believe. Can you post a link to the design, or tell me what parts are on the woofer? By the way, I really like the mids from this woofer.
                              A first order filter is not going to get the results you want. A 4th order will work way better, but will cost more.

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