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  • InDIYana 2022; "Missing Link" theme announcement....

    InDIYana 2022 theme challenge:

    “Missing Link”
    Chuck and I (Ben) decided to go a different direction this year. I suggested picking some interesting less than perfect drivers, designing the cabinet along with the bass tuning, taking a full set of measurements of the chosen drivers in said box, and unleashing the competitive attendees on a xover challenge alone. Basically, we provide the front-end, amplifier, and the speakers. The entrant brings the xover. (Entering the challenge is still not required.)

    Since the unfortunate passing of Rick Craig and Jeff Bagby; This is the first time this kind of challenge has been done since Jeff won (tied, along with Dennis Murphy) at the event Rick hosted all the way back around 2000 (At least to my knowledge). I felt it was time we gave this a try again being that it has been that long. We also have not tried this challenge at InDIYana before. Software and tools available are vastly different than they were 21 years ago, especially since Jeff dropped his software suite in about 2005.

    I vetted the idea with several people that typically attend, and the idea was universally accepted. It gives a lot of options with an open xover platform. The lesser experienced or thrifty builder would have an easy go of things with all of the info supplied. While purchase of drivers or building cabinets is not required, builders are allowed to do so.
    Cabinet dimensions will be provided should someone want to give that a go for audible personal voicing. Drivers total runs about $250/pair. This is not an immense outlay of money, even well under past allowed theme costs, and the drivers are not bottom of the scale in performance. Cabinets are relatively simple, and of modest size. You are welcome to bring the cabs you build to the event to show them off, but for the competition the cabinets that I have built will be utilized.

    Drivers are to be the Dynavox LW6004HR-N kevlar honeycomb woofer and the SB Acoustics SB29RDC (SB29RDAC is identical save for an aluminum faceplate).

    The provided woofer alignment is about the best I can do. The driver has a somewhat weird set of specs. I used woofer #2 for the larger Vas, as the other will likely break-in a little towards it.
    It's high enough Qts to run sealed, but it didn't get low enough extension for me.
    Therefore, a vented-stuffed box comes out better, but I had to cut back on the box volume to keep the Xmax in check. I think a 15 ltrs 7" 2-way with extension to about 40Hz is reasonable. I also added 0.4 ohms for xover DCR into the box sim.

    14.5” x 10” x 11.5” HWD external. I used a 1" thick stair-tread for the brace (solid, no holes) about 2/3 the inside depth, positioned at 7.5" on center inside height, about 3/8" below the port. Since the port and brace are about the same length, I added a hardboard brace across the end of the port to tie in the top, port, and brace. Port exit has a 1" roundover, and is a 2.5" D (grey elec conduit) x 7" long. Lower cavity is well stuffed.

    I took the loaded cabs down to Coop’s place (thanks, Coop!) for a full set of measurements in his lab/barn. We even went through a second set of taking measurements because Coop felt something was off. Gating measurements allows good Impulse Response with valid data down to ~300Hz in his setup. Coop used ARTA/LIMP for the data retrieval. There is a read-me file for understanding the files’ nomenclature included in the .zip file that Coop has provided. I have included all of my data as well in the file, as well as the applied box model from Unibox.

    I know normally the theme is announced in July before MWAF and Tent Sale, and while I would have liked to do that, the drivers Chuck and I wanted to use were on back order awaiting arrival. They finally arrived on my doorstep the first weekend of August, and I knocked out the cabinets the following week as I had vacation time. I was able to get them down to Coop’s on August 28th for the first go around and then again on Sept 11th for the further task of bettering them. So as you see, there has not been much time left in getting the information presented and announced to the masses.

    The cabs have 4 binding posts present to the rear to facilitate connections. Due to time frame and how fast we go through the theme challenge, we highly mandate that banana plugs be utilized for these points of contact, and that the xover boards brought by the entrant be fitted with banana jacks for the inputs from the speaker cables. The components must be mounted to a board of some sort, and connections must be solid via solder, barrier strips, wire nuts, euro-blocks, spring terminals, or lever nuts, etc. There is to be no flaky alligator spaghetti type of connection, or cardboard as mounting structure. This is to prevent accidental misconnection, shorting of contacts, or loose or other connectivity issues and make sure the entrants have the fairest chance in the competition.
    As a safety measure, there will be a 100uF polypropylene capacitor in series with the tweeters to prevent accidental overdrive should something occur or be miswired by the entrant. Schematics of the entrants’ xovers will be required for perusal, and the entrant is to plug in their own xovers during the challenge.

    On a personal note, I'll be making my xovers fit an 8.5" x 7" board, and that should be a good enough size for the challenge. Yes, I will also be entering, and I feel me purchasing the drivers and building the boxes to be measured gives me the right, with no particular advantage over anyone else as I will be using the same set of data.

    There is no dollar amount limit on the xovers for this challenge. Use what you like, or as many parts as you like! While the drivers have been chosen, and the measurements taken, I want it to be clear that this is not Iron-Driver. We will not be taking measurements of the finished system except for matching the output levels between entrants via an RTA on a running Omnimic or other program/software and gear. Judging will be conducted via a show of hands as is the norm. In the event of a tie of votes, the xover's visual presentation will decide the winner if a recount of the 2 options still results in a tie. Should there be similarities in xover networks entered, Chuck and I may lump entrants into sectors for a bracketed system of judging as done prior.

    As usual, we are targeting the month of April, 2022. More details will be presented as the time gets closer as to where and what days.

    Let’s hope that Covid is taking a backseat by then, and we can all have a very splendid time at InDIYana 2022!
    I hope to see you there/here.

    Wolf

    PS- The forum does not allow the upload of the data package .zip file, I will still plan to have it uploaded to the event website for download in the next week or two at the latest, maybe this evening depending. It is an 18.5MB file size as compressed.

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    "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

  • #2
    Apparently, MAC forum allows the file size, so it has been uploaded for the moment here:
    https://diy.midwestaudio.club/discus...ement/p1?new=1

    Updates to the website will be forthcoming...
    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


    • #3
      Side-note; I have build photos of the cabinets, but I have not pulled them from the camera yet. The 8.5" x 7" boards will fit inside the boxes with a removable baffle as I have done. However, for the contest, all xovers must be external for connections.

      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


      • #4
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        Oh- I did not relieve the back side of the baffle for the woofer as it seemed open enough to not cause any interference.

        I really like these CMC/Connex locking nanner-jacks too. No more cracking/splitting of the locking-style plugs!

        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


        • #5
          Can an international entry be made by proxy? I'd love to have events like this here in Aus but as far as I know we don't :(

          Comment


          • a4eaudio
            a4eaudio commented
            Editing a comment
            You should definitely do it! InDIYana International Speaker Event sounds nice!

          • DeZZar
            DeZZar commented
            Editing a comment
            It would definitely be awesome - I just don't really have any idea how much interest there is and how many serious designer DIYers there are here. There are a few businesses that support DIY - would need to find a few sponsors and somehow gauge the level of interest - maybe make it like a mini DIY audio trade show?

          • Wolf
            Wolf commented
            Editing a comment
            Geoff Millar
            Wintermute (a mod over there, Sydney)
            AllenB (a mod too)
            PeteMcK (Sydney)
            Mardi (Sydney)
            _henry_
            TMM
            johnmath
            Andy Graddon (Andy G, maybe? He's not been active for a bit, but he might come out and play.)
            Rabbitz (Newcastle)
            blakkshepeaudio (Keith Arnold, Country Victoria)
            Frangus (Sydney)
            gainphile (Melbourne)
            tktran303 (Melbourne)
            andyr (Melbourne)
            fergs1 (Melbourne)
            Moondog55
            Brisso57 (Brisbane)
            Jye (Brisbane)
            mainframe99
            zog666
            fringy75 (New Zealand)


            ^^^^There are lots of guys on diyaudio that live in Oz.
            Last edited by Wolf; 09-19-2021, 02:54 PM.

        • #6
          You could always host one!

          That said, I would not be opposed to having a set of xovers shipped in, but return shipping would be the sender's responsibility.

          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


          • #7
            It's been a really, really long time since I've visited this place. Interesting timing for this to show up . I wonder if I still remember how to build a crossover.
            DARPA Jr - 2015 InDIYana Winner - RS180-8 + RS100P-8 + ND25FA
            The Aria's - RS150-4 (or RS150-8) + XT25SC90
            The Mariposa's - TEBM65C20F-8 + ND16FA
            The Canzonetta's - RS100P-8 and ND16FA
            AudioSource AMP-100 Mods OR Pyle PAMP1000 Mods

            Comment


            • #8
              This is a great theme Wolf! I may be able to do another theme participation.

              If planets align I may have a non theme build by then.
              Electronics engineer, woofer enthusiast, and musician.
              Wogg Music
              Published projects: PPA100 Bass Guitar Amp, ISO El-Cheapo Sub, Indy 8 2.1 powered sub, MicroSat, SuperNova Minimus

              Comment


              • #9
                What are the chances of getting rid of that extra 100uF protection cap?

                I totally understand the desire to protect your tweeter. But, a quick review of the network validating that there's some sort of a cap in series with the tweeter (assumed parallel network) S/B sufficient at quick glance to determine they're "safe."

                A quick/easy way to avoid visually directing the network would be to just hook up each network to DATS and run impedance sweep on it. This is what I'd do if it were my amp - a dumb overlooked error could exist on the woofer circuit just as easily as the tweeter.

                Yes, this is extra work and annoying. I understand. But, I'm a purist and want to ask. Also, I'm looking out for your amp

                Something to consider - nobody checks XO networks or DIY speakers in general at any "competition" or DIY gathering that I've seen. It could easily be an amplifier frying situation in some of those situations as well (thank goodness for protection circuitry). Food for thought.
                SEC DIY 2014 Speaker Show is on! *November 8th*
                Wanna win a set of Newform Research R30 ribbons?!?!
                SEC DIY 2014 Thread

                SEC DIY 2012 Speaker Show
                SEC DIY 2011 Speaker Show

                Comment


                • #10
                  I'm not worried about my Crown, as it's made to take the faults. The tweeters on the other hand need protected from miswired issues. While I am also a purist, I feel the time savings, piece of mind, etc is worth the addition to the circuit. Mind you- it is NOT an NPE. It's a nice Erse PulseX, for whatever it's worth, and it's far away from the active bandwidth. I also don't want to sit and DATS everything first. Like I said- it's not something where we will measure FR/Z of every entry.

                  Others have suggested we do the xover boards blind, but it really makes a lot of work. I am open for suggestions in terms of simply doing this. While I am entering, I will not vote, as I never do in the challenge. I just count the show of hands. A stipulation- if we do this blindly, then the speakers will be setup for toe-in only and not straight-forward placement. Still- I would like an easy method of blinding them.

                  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


                  • #11
                    Just thinking out loud here... I haven't even looked at the files so I have no idea if that 100uF cap would be hard to deal with or not. With that said, I agree a quick DAT's sweep and visual inspection the day of the event should easily flush out any potentially questionable xos. Anyone interested in submitting a xo for the theme would have to have their xo's (attached to the DUT's of course) impedance measured and visually inspected before the event even got started. That's what we do with tech/safety inspections in drag racing. You don't get your car number until you pass tech. With banana plugs and DATs I can't believe it would take more than 60 seconds per entry. That certainly could eliminate the need for the huge cap and possibly make things easier for designers. If I wanted to have a parallel resistor or LRC across the tweeter terminals to tame Fs.... now there is another reactive component there.
                    Craig

                    I drive way too fast to worry about cholesterol.

                    Comment


                    • #12
                      The 100uF shouldn't cause too much of a pain, that can easily be added to the models when designing the crossover.

                      Totally agree with a DATS sweep before lighting up the speaker with the amp, just a good preventive measure in case of error. With a fully constructed entry like usual the entrant will have presumably tested on an amp live so there's less risk of a big "oops". In this case, for example my entry would be strictly theoretical and assembled without a full system test.
                      Electronics engineer, woofer enthusiast, and musician.
                      Wogg Music
                      Published projects: PPA100 Bass Guitar Amp, ISO El-Cheapo Sub, Indy 8 2.1 powered sub, MicroSat, SuperNova Minimus

                      Comment


                      • #13
                        I get that (most) amps have protection, which is why I mentioned it. I just would prefer not to rely on it if I don't have to.
                        If I could offer some guarantee that I'd be attending, I would gladly offer to come and measure everything with DATS the day/night before the event (just in attempt to catch faults). Anyway had to ask.

                        I think blind is an excellent idea and welcome it. You could have a sheet up behind the speakers and table back there. You could just assign a random number to each entry and let people know what the number is for their evaluation feedback forms. If you're not judging/voting, then your bias is eliminated and not of concern in the rankings.
                        SEC DIY 2014 Speaker Show is on! *November 8th*
                        Wanna win a set of Newform Research R30 ribbons?!?!
                        SEC DIY 2014 Thread

                        SEC DIY 2012 Speaker Show
                        SEC DIY 2011 Speaker Show

                        Comment


                        • #14
                          Originally posted by wogg View Post
                          With a fully constructed entry like usual the entrant will have presumably tested on an amp live so there's less risk of a big "oops". In this case, for example my entry would be strictly theoretical and assembled without a full system test.
                          This.
                          SEC DIY 2014 Speaker Show is on! *November 8th*
                          Wanna win a set of Newform Research R30 ribbons?!?!
                          SEC DIY 2014 Thread

                          SEC DIY 2012 Speaker Show
                          SEC DIY 2011 Speaker Show

                          Comment


                          • #15
                            Originally posted by PWR RYD View Post
                            …If I wanted to have a parallel resistor or LRC across the tweeter terminals to tame Fs.... now there is another reactive component there.
                            This is a very good point

                            Comment

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