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It’s that time audio enthusiasts! Registration for the 2019 Speaker Design Competition is now open! Visit midwestaudiofest.com for details and to list your speaker project. We are excited to see all returning participants, and look forward to meeting some new designers this year, as well! Be sure your plans include a visit to the Parts Express Tent Sale for the lowest prices of the year, and the Audio Swap Meet where you can buy and trade with other audio fans. We hope to see you this summer! Vivian and Jill
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'Tandems'- an InDIYana 2018 theme driven build process...

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  • #61
    Okay, time for some updates....

    Jig number 1 for this build was the Circle Jig I built. The circle-jig build is logged here:
    http://techtalk.parts-express.com/fo...rk-in-progress

    I still think I might have to enlarge the entry into the dust extractor a smidge. Oh- and I did get the second router for the circle-maker...

    Now I had the means to do the updated curved side panels for the Tandems build. I went to Paint and added some circles of what I would be aiming for;

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    You can see how the curves will augment the design, as well as allow the xover to be placed between the outer rear ribs. This looked much better, and would be the direction I chose to approach.

    Jig numbers 2 and 3 are that of the woofer and coaxial through-holes. You'll see later why the use of multiple jigs was required here to reduce the risk of fouling something up.

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    And of course number 4, the coaxial rebate:

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    I actually made the coax rebate twice as I was unhappy with the first template. The final template I used for the coax rebate ended up being a single side-arc. Due to all of the jigs being made to pin in the same center and location, I just rotated the arc into the four positions when I routed. The corners did require some chiseling to get them just right for driver installation. The jig having the longer tongue was for clamping to the cabinet during use, and are the same width as the baffles for even spacing from the nearest edges.

    The woofer rebate is too close to the edges of what I was using for the rest, as well as being very close to the baffle edge as it set, so it had to wait anyway. I didn't want to break through the edges when making the cut. IIRC, I even just used the new circle jig to cut the rebates without a jig. Teeth-clenching was inevitable this time around...

    And lastly number 5, the template I made for the side panels. I used a full-scale drawing made with straight edge and compass to get the curves I wanted, and then used the circle jig to cut the curves in the full-sized template. I needed the 2' trammel for these as they were around 19-20" radii for the larger 2, and 5" for the smaller lower curve. The circle-jig was so slick to make these curves too.

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    The jigs for drivers were of course made after the baffles were constructed, but I wanted to lay out the jigs I used first. I might not even be done making jigs for this build, but these are the first 5 used.

    More to come...
    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:
    http://photobucket.com/Wolf-Speakers_and_more

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

    Comment


    • #62
      The inspiration to what follows here was greatly influenced by the making of the circle-jig. With 4 layers of tempered hardboard (HDF), I was amazed at the stiffness of the panel. The thoughts entered, "What would an entire speaker cabinet of this material ______ like?" Many thoughts placed different words there; sound, ring, thunk, and even lift. This project then went into the first tier of 'snowballing', as I like to call it, where a project becomes more of a mission. (With the Cecropias it was the coil jig in a round xover for another example. The Canvas was a higher order xover than necessary.) I can't just leave well enough alone and make it simpler. I have to walk around the barn to get to the door and make the project more difficult as well as test what I can accomplish when I put my mind to it. In a nutshell, this is why these are likely the most difficult build I've ever attempted to date.

      There are other DIY-ish examples of this HDF-lamination method. Keith did several layers in this year's 'Bare Minimum' entry. Tom Zarbo has curved several pairs this way. Bill did large curves with it in his Kowaxial coax build last year. Ed Rosenquist has done it several times over for Vapor Audio in the Nimbus and Aurora. Most of them I've seen in this type of build have been utilized in curves and done a layer or 2 at a time. En route for my Tandems, I chose to make both trans-lam areas and plywood panels with it, something I've not really done much of before in either case.

      So, I bought a lot of hardboard in 1/8" thickness. At roughly $6/sheet for 2' x 4' panels from HD. I cut 2" wide strips at 32" length to achieve 40 pieces of HDF, followed by 5 pieces of same dimension of 1/4" plywood underlayment, and then 2 pieces of 0.75" plywood at same dimension. That led to this:

      Click image for larger version

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      I then made a jig (number 6!) to drill a hole at the same position on every piece in the drill press for a 1/2" dowel to be inserted through one end. The other end was left like a feeler-gauge for spark plugs. I then proceeded to glue up the layers with Gorilla glue, using the dowel as a vertical alignment tool.When I got through the stack, I laid it down on newspaper atop the table saw for a flat surface guide to align the other end. I used aluminum stock to clamp the sides evenly and keep them as straight as possible. After the glue set, I removed the foam expansion excess, ran the 'board' through the table saw for squareness along the length, and the miter saw squared up the ends. I had a 2" x 8.5" x 32" translam HDF/ply material as a result.

      The next step was to saw the board in half across the width lengthwise. ie- to 'resaw' the board into 2 half-thick boards. After some tripping of the breaker (15A) on the power strip that the table-saw was plugged into just trying to smooth out the width on one side let me know the table saw was not going to be able to do this. Local fellow builder Steve (skvinson) recommended a local woodworker space, Three Rivers Woodworking Club, to try and get this step done. I paid a small fee for a 2 week membership and the host for the day proceeded to help me get this resawn on their large bandsaw that is setup for resawing only. A couple swipes through the joiner to square it up on the faces, and off we went. Post-cut, we took them to the barrel-sander to both smooth and even out the thickness on both pieces at the same time. I bet they went through that sander 100 times, with me on the shove-in, and he on the pull-out. When they get very close to flat, the belt drive does not have the torque to pull them through and the sanding drum can leave low spots in the surface if you don't help the boards keep moving. After this point, I had 2x 32" x 8.5" x 7/8" thick boards. Apparently, I don't have a photo of the twins after they were separated. He then insisted I go to the down-draft table and hit them with some wet-sanding. They were smooth as glass when I left the shop that morning.

      The next step was to measure carefully, and miter one cut at a 45* across both boards to make them into front and top pieces. Measure 5 times and cut once. Heck, I bet I measured 10 times before I cut it to make darn sure I didn't have to start over. Being that these are all 4 from the same piece, the pattern matches from bottom front edge to top rear edge after they are glued up. The key is to flip the tops from the one they were cut from and glue to the other piece. This kept the wooden dowel pin from being visible and on the inside. I also backed both of the top and bottom boards' inside surfaces with another piece of ply in case they want to split later.

      Click image for larger version

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      I'm likely at my word limit, so more to come...
      "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:
      http://photobucket.com/Wolf-Speakers_and_more

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

      Comment


      • #63
        More pieces cut out to make the midrange chamber and the Isobaric chamber:

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        Then I used corner cut-offs from the Stance project and some other pieces to seal off the ISO chamber and eliminate excess volume between the woofers if possible:

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        I added a spacer between the chambers atop the ISO to ensure the glue-up was square and strong:

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        At this point I cut the rebate for the coax, and cut part-way through for the outer woofer's through-hole on both sides of the baffle. This way I could flush-trim later and still make sure everything would fit. Then I cut the coax through hole and relieved the back of the baffle for breathing room.

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        More in a few...
        "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:
        http://photobucket.com/Wolf-Speakers_and_more

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

        Comment


        • #64
          Inside rear:

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          Front rebate for coax:

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          coax-rear:

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          And then the ISO, mid chamber, backing for top, backed baffle were all glued up together:

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          My 10" x 7" x 3" ISO volume was reduced to 10" x 5.5" x 2.25" dims. I added a triangular brace in the aft apex of the midrange chamber. In 2 stages, I added the sides 2 at a time:

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          Stay tuned....
          "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:
          http://photobucket.com/Wolf-Speakers_and_more

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

          Comment


          • #65
            After I flush-trimmed the sides t the baffles, I was able to finally cut the woofer rebate then through-hole in that order. I used MDF to make sure the rear edges of the front and top sector met the requirements of both the slot-port top and that of the soon to be hinged arrangement at the inner woofer location. MDF in 1/2" and 3/4" are the correct thickness to flush the angled and vertical edges to. The front top edge was rounded with a 1" roundover, and dimensions of the bottom most and rear-most were trimmed to the required dimensions. I then laid on 2-3 coats of Watco Danish Oil.

            And this was the result:

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            I followed that with a brush on coat of polyurethane, and showed one off at Meniscus DIY last September (Thanks, Bill, for the photo!):

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            And this is largely how these portions have remained since then. When February hit, it was really dry and cold, and the baffle/top had some de-lam in a few places adjacent the plywood underlayment strips. I bought some epoxy to fix it about a month ago, and went to do it a couple weeks ago and they had returned to their former position. I still plan on applying some kind of binding clear-coat, but it appears I can wait a bit. (The other reason they sat for awhile is I built the 'Bar-Gain' soundbar for a coworker. That and I figured if they were going to crack I wanted to allow it so I know what I had to fix. I can glue up wood, but a cracked driver frame is not as congenial.)

            While I was finishing these last fall in the basement, I was also creating my own HDF-ply to slab-side these previous pieces as in the drawing. I used a piece of flat MDF as a table with a clamped piece for squareness on one end, and slowly laid piece (alternating the curve of the pieces per layer) after piece of 2' x 4' 1/8" HDF to 5 thick while troweling from the gallon of Titebond in between layers to cover the entire surface. I then placed clamps around the perimeter and large bench-weights in the center to try and keep them as flat as possible. I let it cure for a week as it was in the 60s temps around that time. Then I did the second one, same process. One of them had a bit of bow, and the other was negligible. So- I added 3 more pieces each in the attempt to flatten them out a smidge. I was largely successful even if they were not perfect. When they were dry, they sat all winter long atop my table saw as I couldn't do much with them in the cold winter we had. I was hoping they would stay relatively flat.

            I then had 2 HDF-ply boards, 2' x 4' x 1" thick. You think MDF is heavy!! Wow... These were easily 50 pounds, likely more. If my scale was working I'd have weighed them, but no dice.

            Fast forward to about 2 months ago... I built the Zingers in 2 weeks before InDIYana, and then was back at these afterwards. I made my pattern with the circle-jig I posted earlier, and proceeded to cut out the 4 pieces for which these boards were created. Let's first say that I have never had to use as much elbow grease as this process took in my wood-working endeavors- EVER! When the tools go to cut this stuff and they turn and laugh at you, you know you are in for some really rough wor-* (I mean fun!)... times ahead. I had to go get new Bosch jigsaw blades to cut these out. Even though the dull one I had been using didn't mind MDF or plywood, it literally would not cut this stuff. 3 Progressor blades later, I had 4 rough-cut panels close enough to flush trim on the router table. The Ridgid Jigsaw got uncomfortably warm a few times and I had to give it a rest. More or less I cut one out every weekend over the last month, following it up with screwing the template to the piece, and then flush-trimming them in the table- to which the flush-trim bit kept trying to throw the workpiece. I had a 1.5" long Whiteside flush trim bit in the Triton 3.25 HP router for this job. Being they were curved edges it was not easy to guide by fence. So, I planted my feet, and held the pieces like a vise-grip to avoid the initial throwing on contact and slowly powered through the process. I have never had this be so trying in the past. It was a lot of work to cut these out, plain and simple.

            Then I clamped the 4 pieces together to sand them and have them be the same size. I had to start with 60g just to remove the thicker spots, and worked my way up to 400g once they were all the same size. The new Ridgid variable speed orbital sander I just got is a nice addition and did the job rather nicely. After I was done, the edges just shine on their own without a finish applied. I may still have to flatten a couple of the pieces on what will be the inside so that they can meet up with the back/bottom/bracing without much trouble. This will be jig #7 to get that job done.

            The remainder of the 2' x 4' panels will be used to brace internally wherever possible, as it is very strong stuff.

            Some pics of the edges before I got most of the tool marks removed:

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            And a mock-up of a front/top clamped between 2 unfinished panels, just to get the idea of how they will end up:

            Click image for larger version

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            Thanks for looking! More to come... when I get time....
            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:
            http://photobucket.com/Wolf-Speakers_and_more

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

            Comment


            • #66
              Holy cow Ben those look amazing!

              Comment


              • #67
                Glad to see the detailed update on these bad boys! Definitely a long term mission here, and I'm excited to hear them sometime soon!
                Voxel Down Firing with Dayton SA70
                Translam Subwoofers - The Jedi Mind Tricks
                The Super Bees - Garage 2 way
                SevenSixTwo - InDIYana 2018 Coax
                The Defiants - InDIYana 2019 "Bare Minimum" Build

                Comment


                • #68
                  They have kind of become an attempt to out-do those of the British coaxial empire. I call the HDF-ply my 'poor-man's panzerholz'. They've definitely become something other worldly.

                  Thanks, guys,
                  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:
                  http://photobucket.com/Wolf-Speakers_and_more

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

                  Comment


                  • #69
                    Nice progress, I hope to hear these someday. I think the largish and irregularly shaped midrange enclosure is a great idea.

                    Comment


                    • #70
                      The larger the mid enclosure, the more it can do what it does best while unhindered. In this particular case it's 5 ltrs, and while that is not large, it's pretty good sized for a midrange. It's actually just shy of being a good volume for the midbass operating as a woofer with reasonable extension. As a ROT, I tend to prefer to not have a flat wall behind my midranges. This is piece of mind to know there is no immediate parallel surface for direct internal reflection. This design form follows function under that criteria.

                      I have much more work to be done....
                      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:
                      http://photobucket.com/Wolf-Speakers_and_more

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

                      Comment


                      • #71
                        Nice Wolf. I have been waiting to see this build.

                        Comment


                        • #72
                          Nice looking cabs. Look forward to hearing these someday. As I read your long description of the flush trimming process, I could remember how difficult it was to flush trim my Kowaxial speaker curves. That stuff is some really tuff stuff! I trimmed the laminated material as close as I could get to the edge before using my router and the flush trim bit. Even then, it was a very slow process, taking off just a little bit at a time to complete the trimming process.
                          SideTowers: http://techtalk.parts-express.com/fo...corundum-build
                          Totally Flat: http://techtalk.parts-express.com/fo...5-totally-flat
                          Plumber's Delight: http://techtalk.parts-express.com/fo...notech-winners
                          Linehopper: http://techtalk.parts-express.com/sh...Esoteric-build

                          Comment


                          • #73
                            Looking good Ben, I'm glad to see these coming along!

                            Comment


                            • #74
                              No doubt, these are one of your coolest builds yet. I'm very impressed with those cabinet construction materials and all the jigs to make it happen. Bravo!
                              A mains
                              The Ventures
                              Open Invit8tions
                              RSR
                              Sound Troopers
                              Acorns
                              442
                              DGBG's
                              The Monuments

                              Comment


                              • #75
                                Thanks, guys!
                                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:
                                http://photobucket.com/Wolf-Speakers_and_more

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

                                Comment

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