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Vintage 10" Sub build - TAKE 2!!

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  • Vintage 10" Sub build - TAKE 2!!

    I've been wrestling with a sub build for quite awhile now that was detailed here. After some difficulty with how the box was going together (i.e. going together terribly) I decided that I needed to reassess things and do a bit of redesign to get somewhere that I'll be much happier with. I originally planned on a 3 cu^ft enclosure tuned to 20.75Hz. That resulted in an 22" cube external enclosure which ended up being quite large. I have since redesigned things for a 2 cu^ft enclosure that will be 19" cube. Only a 3" difference in each dimension but I think it will provide enough of a difference visually where it won't seem quite as monstrous.

    I'm still keeping the same design aesthetic of a "Vintage" sub. The enclosure will be a wrapped in a walnut veneer and then wrapped with a large band of gray acoustic fabric to give it a look similar to an old 50's stereo cabinet.

    Transfer Function:

    The red line below is the initial 3cu^ft design and the yellow is the new 2 cu^ft box. There is a bit of difference here. The smaller enclosure has a little lower output at 20Hz but this is a trade-off I'm willing to make. I do gain some around 30Hz but may not be noticeable? Though really, anything I end up with will better than what I have now.

    Click image for larger version

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    Enclosure:

    Some Sketchup shots that show the smaller enclosure. The design is very similar to the original. Rounded edges, down-firing port, with a very recessed driver. I had to recess it enough to avoid the sub from hitting the acoustic fabric which results in a very thick baffle, 2.75" in total. The outer recess is 1.5" deep and the inner 1.25". The slot port is a little longer here. It runs up one side and extends out along the top to about middle of the box. No amp box this time around and honey-combed bracing rather than squared. I also didn't model the feet here but there will be some.

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    The design can't change now! Gotta role with this and make it work.

  • #2
    First order of business will be to try and salvage the moulding I'm using for the corners. I have extra material for two corners but not four. I tore down the original box and now need to try and mill out some MDF from the edges of the moulding. I need to try and take this...

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    ...back to this...

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    I'm hoping a combination of a few passes on a table saw followed by a few on a router table will get me there. Won't be without it's challenges.

    Comment


    • #3
      I've got a little of that stuff, and it was pretty expensive if I remember. Probably even more nowadays.
      Good luck getting it salvageable! I like the design, those larger round-overs just add a bit of pizzaz to it.

      TomZ
      Zarbo Audio Projects Youtube Channel: https://www.youtube.com/channel/UCEZ...aFQSTl6NdOwgxQ * 320-641 Amp Review Youtube: https://youtu.be/ugjfcI5p6m0 *Veneering curves, seams, using heat-lock iron on method *Trimming veneer & tips *Curved Sides glue-up video
      *Part 2 *Gluing multiple curved laminations of HDF

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      • #4
        Thanks, Tom, Yeah, it wasn't cheap but is pretty neat stuff. Any pointers on assembly? The first time I put the box together it was not square at all.

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        • #5
          Had some time this weekend to work on the moulding and getting it back to a usable state. I have some sanding/scraping/chiseling to do but I think I'll be in good shape here. Here's one of the corners...

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          • #6
            When working with MDF gotta predrill the screw holes or will always get that splitting.
            I'm certainly not good at this. Just stubborn enough to keep going.

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            • #7
              If those holes were there as part of the construction of the cabinet I absolutely would have pre-dilled them. They are only there as I had to screw a few squared up pieces of wood to both sides of the moulding to use a jig on a router table. These corner pieces are going to get shortened by about 1 1/2" on both sides and since the holes aren't very deep, I fully expect the splitting to get chopped off.

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              • DrewsBrews
                DrewsBrews commented
                Editing a comment
                ah cool then

              • unclejunebug
                unclejunebug commented
                Editing a comment
                Though, expectations and real world results can often be very different. Hopefully I'm not wrong! haha

            • #8
              I had some time to cut the sides and corner moulding down for the smaller box size. This new dry fit looks a lot like the old dry fit only smaller :D

              It does look and feel like a better size overall than before...

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              • #9
                I had some time over the weekend to get started on assembling things. I don't have any band clamps and decided to go with some actual pocket holes to help hold things in place. While I like the look of the rounded corner moulding, I find it difficult to work with using the tools I have and likely won't try it again. I made a bit of a jig to try and get things to go together square, and while it's better than it was, it's not quite as "perfect" as I would like. That being said, I can't change it again so I will have to live with what I've got

                The current state looks a lot like the dry fit just with pocket holes filled with dowels and then trimmed...

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                Last edited by unclejunebug; 01-23-2023, 08:00 PM. Reason: grammer

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                • #10
                  I decided I needed a little me time so I took the day off from work and spent all day on this project.

                  First off I smeared Bondo around the rounded edges and covered the dowels that are filling the pocket holes. The dowels weren't quite long enough to fill the entire pocket so there was space at the back of each dowel that needed filling. I cheaped out and got dowels rather than the Kreg pocket plugs since the Kreg plugs are like $9 and dowels were $3. I figured I'd be doing some amount of filling with the Kreg plugs anyways so I went with the cheaper option.​..

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                  One thing I found difficult when working with this moulding was getting the adjoining panel to sit flush with the edge where the round-over begins. I don't know if there are tolerance issues with the moulding or with the MDF I'm buying at my local HW store but sometimes the panel would extend just proud of the round-over. The bondo helped with smoothing out the transitions on several edges...

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                  After that I got out the router table and rabbeted the inside of the cabinet on the top and bottom to accept the top/bottom panels. It was a little cumbersome since my router table top is rather small so at least half the cabinet was not being supported by anything. The panels that make the top/bottom sides are 1" thick and my plan was to laminate two 1/2" thick pieces together. I marked the shape of the rabbet onto one 1/2" piece, cut that out with a track saw, and then rounded the corners with a sander. The fit isn't pristine but it's tight and is good enough for me. In addition to the standard wood glue I plan to put a bead of epoxy into the rabbeted channel to help fill any gaps (unless anyone can think of some reason both adhesives shouldn't be applied simultaneously?)

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                  • #11
                    I then rolled some glue onto the inserts and to two other 1/2" pieces of MDF, nailed the crap out of the inserts so they wouldn't shift, and then placed about 200lbs of floor tile on top of each one. I let them dry for about an hour, removed the tile, fit the top and bottom panels into place, and then flush trimmed them to the cabinet. Here's where I ended up...

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                    I still have quite a bit more to do on the cabinet itself. The baffle will get 1 3/4" thicker so I can recess the woofer quite a bit. The other three side walls will get an internal 1/4" piece laminated to them to get them up to 1" thick. I'll then need to build in the slot port and two window braces running from front to back. Right now the hole in the baffle is rough cut. I'm going to start building out the baffle with a piece of 3/4" MDF that will have a proper hole cut with a Jasper jig. Once that's in I'll trim the outside hole with a bottom bearing flush trim bit.​

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