Translam Subwoofers with 18" Passive Radiators - The Jedi Mind Tricks

[skatz]

Can't you clamp the layers together in position desired, and then drill clear through one layer and partially through the next to make the dowel holes? The alignment would then be perfect, and you are plugging the holes with the dowel, so wouldn't that work?

[KEtheredge87]

Can't you clamp the layers together in position desired, and then drill clear through one layer and partially through the next to make the dowel holes? The alignment would then be perfect, and you are plugging the holes with the dowel, so wouldn't that work?

[jhollander]

So if I read this right your baffle will sit in a recess in the walls such that the baffle to wall seam faces the front? Man that's going to be tough to get to look good. I'm sure PL would be fine to seal the baffle, it's the seam that has me worried.

Similar to what 4thtry did on his Line Hoppers, routing a grove might be the best way to straighten the edges. I wouldn't rule out a wider grove and filling it with banding or guitar binding. Maybe a tee molding.

[KEtheredge87]

So if I read this right your baffle will sit in a recess in the walls such that the baffle to wall seam faces the front? Man that's going to be tough to get to look good. I'm sure PL would be fine to seal the baffle, it's the seam that has me worried.

Similar to what 4thtry did on his Line Hoppers, routing a grove might be the best way to straighten the edges. I wouldn't rule out a wider grove and filling it with banding or guitar binding. Maybe a tee molding.

Hi John,

Thanks for voicing your concerns, as I have them too! You've got the general construction idea right. Ive attached a few pictures with a bit of 1/2" ply standing in for the front baffle. The thought of routing a slightly wider groove to even out this seam makes sense. it would help me address these issues, as well as help with that internal 1/4" radius that was unavoidable in the router template process. These are the things I do to try and make translam subwoofers with a minimum amount of waste! I couldn't bring myself to buy 5x the material just to have contiguous layers for these monsters. What I am hoping for is a decent seam that I can fill with some woodmate filler and have it look decent. Additionally, I do plan on making some grilles for these subs, so that would hide any major flaws for a bit... but where's the fun in facing an 18" passive radiator forward without showing it off!

[KEtheredge87]

Try to favor one edge of the board, the side you aren't worried about squeeze out on. In your case, probably the inside edge so it will squeeze more towards the inside of your enclosure.

Thanks Kevin! I picked up a tube of PL Premium at Lowes today. I've got a while before I need it, but I like your idea of biasing toward the inside of the cabinet to "direct" any squeeze out to an area I'm not concerned with. Based on John Hollander's feedback, I may end up with a bit more landing area to work with if I try to route the baffle recesses to be more straight!

[fpitas]

You'll want to cap your PL tube firmly between uses, otherwise moisture will cause it to cure in the tube. I use vinyl caps that fit snugly over the tip.

[Kevin K.]

... but where's the fun in facing an 18" passive radiator forward without showing it off!

[ATTACH=CONFIG]n1333584[/ATTACH] [ATTACH=CONFIG]n1333583[/ATTACH] [ATTACH=CONFIG]n1333582[/ATTACH]

Exactly, screw the grill! Those things are toooo purdy to hide!

+1 on John's suggestion. I like the idea of some black banding/binding around the baffle, that could look pretty sharp. Clean up the recess with a router like you were thinking Keith and it would only leave a little bit of work to be done with a chisel in the four corners.

[jhollander]

Note, my thought was to route the groove post baffle glue up. Get the best joint you can then straighten it out.

Could also consider an inside outside router template, same as for cutting irregular shaped drivers.

[KEtheredge87]

Note, my thought was to route the groove post baffle glue up. Get the best joint you can then straighten it out.

Thanks for clarifying, John. That makes a lot of sense. Waiting until I have the baffle glued in will give me a solid surface to actually rest the router on while making that groove cut.

...I like the idea of some black banding/binding around the baffle...

Adding some inlay to this project would definitely add another touch of class! When you say some black banding (if we're talking wood) my head immediately goes to ebony, which also makes things expensive (haven't googled yet, but I've never seen any of that stuff come at low prices). Is that kinda what you were thinking about?

[KEtheredge87]

You'll want to cap your PL tube firmly between uses, otherwise moisture will cause it to cure in the tube. I use vinyl caps that fit snugly over the tip.

Thanks Francis. I meant to show you this earlier. I did pick up a little gizmo from lowes that is supposed to help me seal up the tube. I hope it works! I've heard this stuff has a tendency to ooze if left unchecked!

[KEtheredge87]

Alright Guys,

Project update for the night. Before I start, a major Thank You to everyone who's chipping in ideas to help me be successful in this project. I hope one day I can return the favor!

Tonight's work was installing the first horizontal brace in the subwoofer wall. I used 1" poplar dowel rod from Menards between layers 7 and 8 of the subwoofer's wall pieces. In order to get the dowel rod seated in a curved wall surface, I did some custom fit work. I started with a scrap wall layer piece and trimmed the ends off. I needed the curved portion of the scrap piece to support the curved portion of my good piece while I used a 1" forstner bit to make a hole that was just barely over 1/2" deep. This hole was situated with the brad point of the forstner bit directly on the line where my good part met the scrap support part, so that I would get a half circle cutout in my good part.

From there, a chisel helped to square-off the round opening and be a snug fit for the dowel rod. Matching cavities were made in layer #8 that stacked on top of the dowel rod, thus sandwiching the dowel rod into the wall. I made sure to cut the dowel rod so it fit snugly, and can't rattle around back and forth. Even if there was some space, I used 5 minute epoxy to set the rod into the top and bottom of each layer piece, and filled the corner parts with as much epoxy as I could stuff into place.

Keen eyed observers may also note I had to upgrade my clamp size! The Irwin 6" quick grips ran out of clamping length after 7 layers. Good thing I went to harbor freight and stocked up on 24" clamps the other night. Only had to buy 8 after taking stock of what I already had (thankfully not the 20 clamps from 20 friends that I joked about the other day!)

I'll need to repeat this process between layers 17 and 18 for the second horizontal dowel rod. Once the cabinet is more or less together, I've got a plan to mark locations on the ceiling using dowel rods and blind nails (double ended). More on that as I get there.

For now, I'm pretty satisfied with the way the brace came together!

[Kevin K.]

Adding some inlay to this project would definitely add another touch of class! When you say some black banding (if we're talking wood) my head immediately goes to ebony, which also makes things expensive (haven't googled yet, but I've never seen any of that stuff come at low prices). Is that kinda what you were thinking about?

Something like this. I didn't look around a lot, but you'll get the idea. It's available in different colors also.

http://www.ebay.com/itm/8-pcs-5-feet...3D182520043380

[jhollander]

+1 in the guitar binding, there's another web site but I can't remember it right now...

Here it is http://www.lmii.com/products/mostly-...ings-purflings

[KEtheredge87]

Hey Everyone,

More progress to report tongiht. I finally finished all my MDF panel glue-ups for my front and rear baffles, which freed up some more table space. I used that real esate to start gluing layers together for the second subwoofer, so now I have both of them going. I also got bolder and glued more than 2 layers up at one time. I managed to do four layers at one go, which seems to be about the limit as far as glue squeeze out management. Any more layers and I'll need multiple wet rags to handle it all. Ultimately, I glued six layers on the second subwoofer, which makes it ready to have a dowel rod installed between the 7th and 8th layers like I did last night on the first sub.



Outside of sniffing glue, my walnut and okume veneer arrived with heat lock glue and a little roller... as well as my walnut dowel rods to cut some pins for the top layers. Love when UPS brings me some woodworking toys! I also spent some time thinking about that guitar banding idea that Kevin and John floated my way. I'm kinda thinking I'd use some of that stuff as a thin inlay, using a 1/4" wide band of it. I'll wait until I get closer to the final cabinet glue-up before making that choice. I'm not sure exactly how much of a gap I'll be trying to conceal between the baffles and the plywood cabinet walls.

We'll see what I get done tomorrow night. Saturday looks like my calendar is being claimed unless I get up early and do some sunrise work. Cue the Lion King song...

[Gordy]

+1 in the guitar binding, there's another web site but I can't remember it right now...

Here it is http://www.lmii.com/products/mostly-...ings-purflings

Stewart Macdonald
Stewmac.com