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LP THT 26" Build

post #1 of 26
Thread Starter 
I have other sub projects on the back burner, but I had some extra time and a 12" Alpine SWE-1243 car subwoofer on a shelf and I wanted to try it in a Low Profile THT (AKA The Low Rider THT).

I thought it modeled well in HornResp if I doubled the rear chamber volume.

I made the driver cut-out for the 15" Dayton DVC and made an adapter ring for the 12" driver, for just in case the 12" performs poorly in that box.
Of course, I would also need to reduce the rear chamber volume if I switch over to the Dayton.

The wood is cut and I plan on starting assembly after lunch today.
I did not take a lot of pictures, because I didn't think anyone would find it very interesting. But, I did take a few.

If you've seen the Low Rider plans, you know that this first piece is for bracing the driver plate. I made three of them, because the box is 26" wide and the plans say to space the braces no more than 8" apart.












Taper Jig for cutting tapered braces.




The next cut requires a 50 degree angle, but my table saw only goes up to 45.




I placed a 0.42" scrap piece on the table near the blade...




...and got a 50 degree cut.




This is how I set the fence for angled cuts.




One piece needs a 70 degree cut.
I reasoned, what's 70 degrees, but 20 less than 90.
So, I stood the board on edge (90) and set the blade to 20 degrees.
Here you can see a pair of magnetic "feather-boards", to keep the wood pressed against the fence.
You can also see that I installed a sacrificial fence, which should have been 3/4" instead of the 1/2" that I used, but it worked.
It also would have been better to use a tall fence, but the Grip-Tites held the workpiece tight against the short fence and I had no problems.







I got a perfect 70 degree cut.
I also scorched the two ends a little bit, because I fed the part pretty slowly at the beginning and end of the cut. But, that will get glue on it and never be seen again, so no problem.



12" to 15" adapter ring.
I just realized that this will push the driver back by about 1/2". I hope that does not wreck its performance, because of compression changes or something of that sort. If so, I can deal with that if need be.
I applied a coat of water based poly to these pieces, thinking that the gasketing foam might stick better to it.

post #2 of 26
Looking good so far! What part of Dallas are you in?
post #3 of 26
Thread Starter 
Quote:
Originally Posted by flyng_fool View Post

Looking good so far! What part of Dallas are you in?

Thanks! I'm in Forney.
post #4 of 26
What is a stay at home vacation in Forney called?
post #5 of 26
Thanks for taking the time to photograph the process. As with your other build threads, your extra work and attention to detail I appreciate.

I look forward to seeing how this project comes together!

Best of luck!

Kevin
post #6 of 26
As always, your project looks like it should come together without much trouble thanks to the level of precision and detail you always apply. And I'm sure the finish will be topnotch. Thanks for the pics.
post #7 of 26
Forney-cation.

Sheesh
post #8 of 26
Nice pics. Looking forward to following your progress.

Also looking forward to your comparison versus the original THT.
post #9 of 26
I'm in the Dallas area, where did you get your wood?
post #10 of 26
Thread Starter 
Thanks, guys!
TestWork--you had me stumped with that one.

I assembled the enclosure today, but I didn't get a lot of pictures, because I didn't want to get adhesive on the camera.

I ran into some problems, but it is purely my fault.
When I dry fit the pieces, I just checked for fit without making sure everything was square.

When I got to the last 3 pieces during the glue-up, I discovered that some panels were out of square and I remembered that I had some panels laying around that were out of square and I must have used those by mistake. Doh!

This box is destined for the landfill, because it will never pass inspection.
However, I hope it is air-tight and functional enough for tests.

I'd like to make it clear that, having built the Original Version THT and now the Low Rider, the Low Rider is even easier and faster to build than the original. So, don't let my careless mistake discourage you from building one of these beasts.

Who knows, if it tests okay, I may find a way to make it look acceptable.
We'll see.
You will know the box still looks bad if tomorrow's pictures look pretty distant--like I set up my camera in Fort Worth. If the pictures look like they came off a satellite, then the box turned out worse than I thought.

Here are the few assembly shots I got.
The larger tube is more economical, but a little awkward to handle, so I made a makeshift disposable grout bag.




Shoot some brads.




Apply the goo.




I can't believe how quickly and easily this went together.




That's it for now. I should have gotten a shot of all the clamps on it. Maybe tomorrow.
post #11 of 26
Thread Starter 
Quote:
Originally Posted by mikeflores View Post

I'm in the Dallas area, where did you get your wood?

I picked up some Aruco ply 1/2" at Home Depot in Terrell, which I used for the long, outer box parts, and some cabinet ply at G&S Hardware in Terrell, which I used for the inner panels. Seems backward, but the cabinet ply I used were cutoffs from a previous project.

Here's something worth knowing, since you're in the Dallas area--the McCoy's Lumber in Terrell has 5x5 1/2" Baltic Birch in stock for $24.95/sheet. Other McCoy's in the area may stock it for the same price.
post #12 of 26
I notice you always seem to sneak your Toyota into your build pics somewhere....:P
post #13 of 26
Thread Starter 
Quote:
Originally Posted by RyguyOK View Post

I notice you always seem to sneak your Toyota into your build pics somewhere....:P

Yeah, I really like that truck.
post #14 of 26
Nice use of the ziplock. Kinda like decorating a cake but with some real sticky stuff!
post #15 of 26
Quote:
Originally Posted by PassingInterest View Post

Shoot some brads.

Hey! What did we ever do to you?

Looking good - I have my plans, but won't be building it for a few months, still working on the room itself.
post #16 of 26
I thinking of using a couple behind my screen wall myself pending review by you early builders. PI, I could use a cabinet with cosmetic flaws if you want to drive it up here one weekend.
post #17 of 26
Thread Starter 
Bad news.
It was worse than I thought.
The out of square panels messed it up pretty good.

I thought I could maybe get some FR sweeps anyway, but it rattled pretty bad.
I tried crawling around on it, to put some weight on it to stop the rattling, so I'd know where to shoot some nails or drive some screws, but I never located the spot.

I decided it would be easier to start over than to try to fix it.
I've already dismantled it.


Quote:
Originally Posted by mynym View Post

Nice use of the ziplock. Kinda like decorating a cake but with some real sticky stuff!

Yes, but I'd rather use the "Grouting" comparison.


Quote:
Originally Posted by Brad Horstkotte View Post

Hey! What did we ever do to you?

Haha! That's like, "Fire at Will." Will's an okay guy. I'd rather fire at his brother.


Quote:
Originally Posted by BIGmouthinDC View Post

I thinking of using a couple behind my screen wall myself pending review by you early builders. PI, I could use a cabinet with cosmetic flaws if you want to drive it up here one weekend.

Well, I thought about driving all the way to Northern VA, and it's the thought that counts! Just kidding.
Too late anyway. It has been torn apart.

Thanks for all the encouragement guys.
I messed this one up, but honestly, this is a really easy build.
I just made a really stupid mistake when I grabbed some out of square panels and trimmed them to size, without ever checking them for square.

See you guys next build.
post #18 of 26
Thread Starter 
You guys probably figured out the failure already, but here's what I found, just in case anyone was curious.

The clamping force caused the out-of-square interior panels to pull away from adjacent panels, opening air gaps and causing the rattle I heard during testing.

I had applied the clamps after the entire box was assembled.
It was assembled all at once.

Less than 24 hours later, I carefully pried all panels apart and inspected inside as I went along. That's how I found the problem.
post #19 of 26
Ack! that sucks. Are you going to rebuild?
post #20 of 26
Thread Starter 
Quote:
Originally Posted by RyguyOK View Post

Ack! that sucks. Are you going to rebuild?

Yes, but I have to work the rebuild in when I can, so I can't start rght away.
It's disappointing that I messed this one up, but looking on the bright side--I get to do another build!
post #21 of 26
Quote:
Originally Posted by RyguyOK View Post

I notice you always seem to sneak your Toyota into your build pics somewhere....:P

Yeh, I bet he does that to make fun of me because I sold mine when it had hundreds of thousands of miles on it and many more left! I also bet he loves to rub it in that he's still in possession of a finely tuned T-100!
post #22 of 26
post #23 of 26
Thread Starter 
Quote:

Lost by a nose! That had to hurt in more ways than one.
post #24 of 26
Thread Starter 
Quote:
Originally Posted by erich h View Post

yeh, i bet he does that to make fun of me because i sold mine when it had hundreds of thousands of miles on it and many more left! :d i also bet he loves to rub it in that he's still in possession of a finely tuned t-100! :d

:d :d
post #25 of 26
Quote:
Originally Posted by PassingInterest View Post

Lost by a nose! That had to hurt in more ways than one.

I thought it appropriate for this thread as for a minute there it looked like you might complete the first Low Profile version documented in this forum. There is one over on BM's forum but that doesn't count.
post #26 of 26
Thread Starter 
Quote:
Originally Posted by BIGmouthinDC View Post

I thought it appropriate for this thread as for a minute there it looked like you might complete the first Low Profile version documented in this forum. There is one over on BM's forum but that doesn't count.

Oh man, I was so close, too!
I agree--if it ain't documented here, it doesn't even count!
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