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Discussion Starter · #1 · (Edited)
Background:
I first got into car audio about 3 years ago, when a friend gave me a pair of Sony subwoofers in a box with a Kenwood amp for free. I got into it only to the point where I got it installed and working (amp screwed to the side of the box), added tweeters, replacing my headunit, and replaced the factory woofers.

Other than spending a fair amount of time with an RTA, I had basically lost interest in doing anything else.

About two months ago I had to pull the sub box out of the trunk to make room for a huge package, and it inspired me to finally mount the amp under my parcel shelf. Since then I've been going through and correcting everything else halfass about my original install.

I've been using the plastic mounts that came with my replacement speakers, but they actually really suck. They are flimsy, don't fit well, and don't do anything to seal the speaker to the door.

This is definitely detrimental to their sound, and so would need to be replaced.

I dug out the OEM speakers to take a look at their built-in mount, and realized they were actually angled up toward the driver.

While it would have been pretty easy to just cut out a new flat mount and call it a day, I decided to copy the angled factory mount.

Car manufacturers try to make their cars as good as possible as cheaply as possible. Any positive attribute becomes a selling point. This includes their sound systems, especially in recent years. While the actual speakers were not very good, I'm sure some engineer was paid to make them sound their best (or at least as good as their manufacturing ability and budget allowed), since a properly designed mount does not cost much more than a poorly designed mount.

So it wouldn't hurt to start there.

Introduction:
I live in a basement apartment at the moment, and don't have access to a lot of big tools. (table saws, planers, belt sanders, etc) I also don't own a proper router. So I have to make do with what I have.

Originally I was going to make them out of MDF which I'd coat with some sort of sealant, but I found a better, easier solution in my wood pile: PVC lumber.

For those unfamiliar, PVC lumber is exactly what it sounds like: long, flat boards made out of PVC. You'd use it as a rot-proof alternative to wood for building outdoor trim, and can find it in the lumber section of any Home Depot or Lowes.

Its sold like wood, cuts like wood, and is priced like wood with one major difference- unlike wood, it does not need to be coated with anything.

Tools and Materials:

1) Dremel tool, with router bits and circle guide. (Good)
Router (Best)

2) Hack saw (cleanest cut) OR Sawzall (if you lack patience... like me...)

3) Regular PVC Cement- you can find it in the PVC/Plumbing section of Home Depot. The brand I bought is called "Oatey," and is the kind used on piping.

4) Sandpaper. Palm sander optional.

5) PVC lumber- I used 1/2" because that's what I had lying around, but 3/4" or 1" might be easier.

6) Closed-cell foam- mine came from Sound Deadener Showdown, and was leftover from when I treated my front doors.

Method

--Part 1--

1) Determine the inner and outer radii of your bracket. It doesn't hurt to use manufacturer recommendations for the inner. Use your own discretion to determine the outer. (Just make sure its thick enough to be rigid.)
-->My wall thickness ending up being ~1/2"

2) Determine the height and angle of your bracket. This, and your board thickness, will determine how many circles you will need to cut.
-->It is assumed that you have already checked your door to make sure this will fit

3) Trace that many circles onto your PVC board.

4) Then, trace two larger circles. Use the same inner radius as before, but make the outer radius ~3/8" wider. These will bolt to the door.

5) Begin routing the circles. Start with the outer edge This might seem obvious, but your circle jig won't work without material in the middle. Also, some tutorials suggest leaving a 1/2" piece of material on the inside, and finishing up with a jig saw. I didn't need to with my Dremel, but I see needing to with a real router.

6) Once you have finished routing all of your circles, take the two larger ones and set them aside. We will go back to them later.

7) Take the remaining pieces somewhere with a LOT of ventilation. Ideally outside. PVC cement is f***** horrendous, and will off-gas horrifically for a few more hours.

8) Take two of the circles. Coat one face of each with the PVC cement, then push them together. The cement sets pretty quickly. Just makes sure you keep them pressed together for at least 30 seconds.

9) Once its tacked on nicely, coat the top face of your stacked circles with PVC, coat one face of another ring, press them together.

10) Repeat until you have a nice, even tube of PVC.

11) Leave this outside where it won't get disturbed. Preferably overnight. It only says it needs 2hrs cure time, but it doesn't hurt to have more. At the very least, by that point it will stop smelling like ass.

--Part 2--

12) At this point, you have two options:
1. Sand the outer surface of your tube nice and smooth. I used 150 and 220 grit sandpaper. DEFINITELY WEAR A MASK.
2. Save that for later, and skip to next step.

13) (Looking at it from the side) Mark the middle of your tube.

14) (Looking at it from the end) Divide the face into 4 even, equal quadrants, and mark the bisecting lines.

15) Continue those lines down the sides. These will mark the locations of the high, low, and middle points of your angle. (These do not determine your angle, however)

16) Draw your angle onto the side using the points from step 15 as a guide.

17) Clamp the tube into a vise.
-->I used a B&W Workmate. The really basic one. $20 at Home Depot. One of the best tool purchases I've made.

18) Set it so that one of the guide lines from Step 15 is facing up. You will be looking at the angled line.

19) It is imperative that you cut straight down at the guideline from step 15, following the angle you drew on the face. Do NOT change the vertical angle of your cut. Your blade MUST remain parallel to the ground in order for your cut to be clean.

20) If using a hacksaw, simply take your time and be patient.

21) If using a Sawzall, start with a shorter, metal-cutting blade. Cut in as far as it will go while remaining perfectly level. Then, continue the cut using the full-length blade.
-->I found that when I tried starting with the long blade, it wobbled too much resulting in an ugly gouge on one side. Starting with the short blade resulted in a much cleaner cut

22) If you need to flip the work piece over, make sure that the other halfway guideline is facing up. Ensure your cut is level with the work piece.
-->IMHO it ends up cleaner if you try to go all the way through without flipping it.

23) Set this aside.

--Part 3--

24) Pull out the wider rings from earlier. Remember those?

25) Draw up a template for the mounting holes on your car door, and transfer that to the wide rings. Drill out those holes.

26) Take one of your recently cut pieces of angled tube. The flat, uncut face is where your speaker will mount. So, set the cut side onto one of the mount rings to check for gaps. If you're some sort of ubermensch mega-carpenter, it will sit flat. If you're like me, you'll have some sanding to do.

27) Using a sheet of coarse grit sandpaper- preferably on a palm sander- sand the surface as flat as possible. Recheck for gaps. It doesn't need to be perfect perfect, but it certainly helps. As long as 90% of the surface is in contact with the mount. (for structural reasons)

28) Once you're satisfied with the fit, determine the angle your speaker will face in relation to the car door. Sit the tube on top the mount, and draw marks to help you line them up again at that point.

29) GO OUTSIDE, and coat the cut face with PVC cement, coat the interfacing portion of the bracket with cement, and mate the two pieces together ensuring your marks line up.

30) Hold these together- as before- for about 30 seconds.

31) Repeat with the other two pieces. Remember, the tube will face the OPPOSITE direction on the other side. ;)

32) Leave outside to dry overnight.

--Part 4--

33) Once dry, once again don your mask, and begin sanding the inside surface of the tube. Start coarse and work your way to finer grains until the inside becomes one smooth, consistent surface.

34) Take plumbing caulk, and fill in any remaining gaps, both on the inside and outside. Use either your finger or a tool to smooth those flush with the surface.

35) Let that dry for awhile.

--Part 5--

36) Pull out your closed cell foam.

37) Trace the top and bottom of each mount onto the foam. Cut those pieces out.

38) Glue the CCF to the top and bottom of each mount using regular ol' Super Glue.

39) Let dry.

40) Enjoy.

Discussion
After all the time it took to route the circles and glue them together, it took me awhile to get the courage to cut into it. I almost gave up and used wider circles by themselves as flat brackets.

BUT! I am really, really glad that I didn't give up, and I am extremely satisfied with the way they turned out. Other than my ugly foam-cutting job, they look really clean.


Full disclosure: they haven't gone on the car yet, but I'll provide an update once they have.

Any comments, criticism, critiques encouraged. I don't claim to be an expert, only sharing my experiences. ;)

Edit: I forgot to add, it might be easier to make a straight cut if you make yourself a jig first. That being said, I did just fine without one, and I am by no means a master woodworker.

-------------------------------

DISCLAIMER: ATTEMPT AT YOUR OWN RISK. THE AUTHOR WILL NOT BE HELD LIABLE FOR ANY DAMAGES TO YOU, YOUR TOOLS, OR YOUR STUFF.

Be Smart. Be Safe. Wear glasses. Use a mask.
 

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Discussion Starter · #2 ·
FYI, I didn't initially plan on doing a write-up, hence the lack of pictures. But I'll see if I can recreate and take pictures of what I did to make things more clear. I'm an extremely visual person, so I understand how others might need that too. :)
 

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Nice write up! I did something similar with 1" HDPE I obtained from ebay (in 8" width by roughly 3'). So PVC glue was not an option. What I did was to heat/melt the HDPE to "weld" it together as well as some bolt/screws thru the layers. From what I've read, PVC also has a modest melting temp to allow heat welding.

My stock ('04 Chevy Impala) 6.5" door mount was/is almost 3" thick at the bottom and around 1/2 at the top angled of course up and out from the bottom of the door. So it took me two 1" pieces and the remainder of angle slice I cut back on top for the other 1" (to make 3" at thickest).

HDPE is a bit of a PITA to cut due to melting or binding while cutting. Just have to really take your time and move blade in and out when using Sawzall to keep chips clear. I also used nonhardening clay around final mounted speaker.

Here is my pic with the start of the clay laying:
 
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Nice work, BOTH you guys. I just got some 3/4" HDPE today to make baffles for mounting some XS69 into my doors. While driving to get it, I was pondering just how to angle them up as much as possible. Your ideas are helping me out,though since I have a 12" bandsaw in the wood shop, I might just bevel cut the HDPE full width.
 

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Discussion Starter · #5 · (Edited)
That HDPE baffle reminds me of something that would come out of my 3D printer. ;) I just wish it had a build envelope large enough to make a 6.5" woofer bracket. :(

I am very, very jealous of your 12" band saw. :) That and an angled jig sled would have made the process SO much cleaner.
 

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For those big HPDE mounts I used a table saw to get the cut started by attaching the original bracket to the HDPE which gave me the angle I needed. Drilled a hole in the center (I did not cut rings and started solid in the middle). and mounted it vertically on a board attached to the table saw fence.

As the piece is rotated around the drilled center (with the bit left in as a turn axis) it was eccentric. Meaning it followed an axis that brought where I wanted to cut along the diameter of the piece into the blade's axis. So after adjusted right/left and brought the blade up to the rotating piece and cut 1/4-1/2" at a time/rotation. But the 10" saw only really gives you at best a little more than 3" of depth and not enough to complete the job. Then finished it with Sawzall. Sorry no pics of this setup.

Then used a table mounted jig saw (Rockwell BladeRunner) without the arm which is just a up and down blade sticking out of a table. I got long enough blades to cut thru the thickness of the semi-finished piece. Through the really thick parts I found myself stopping every 30 seconds or so, removing the hot blade (quick release on the BladeRunner no tools required) and plunging into ice water to cool.

HDPE is also a little tricky to sand since any heat up melts in and the sandpaper is toast. But despite the name high density, its actually fair soft and easy to cut if you mind the binding causing heat then melt issues. Unlike MDF it is completely weatherproof and stable.
 

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Discussion Starter · #7 ·
I also used the OEM ones as a reference. But what I ended up doing was wrapping a sheet of paper around the bracket, then cut it flush. I then moved the paper to my stack of rings, and transferred the line onto there. That also gave me the proper bracket height.
 

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Discussion Starter · #8 ·
I'm sure both materials are pretty acoustically inert, too.
 

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Very interesting, I'd like to see a shot of the door panel grill also. If it had to be modified or left stock
 

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just as a quick note....use pvc primer before the glue. it creates a permanent bond, whereas just the glue does not.

aside from that, awesome write up!
 

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Discussion Starter · #11 ·
So they're in, and it's definitely an improvement. I still haven't run my door wires, so I'll take photos once that's done.

Because they were based directly on the factory mounts, I didn't need to modify anything on the door. The only fitment issue I encountered was that the "base" rings were a little too wide. After I trimmed that, the door skin went back on cleanly.

Also, thanks! :)
 

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My HDPE pictured above was also the same size as stock mount thus not requiring any door panel modifications.

As CK1991 said: use pvc primer prior to gluing whether you are doing mounts or plumbing.
 

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Discussion Starter · #13 ·
I'll definitely keep that in mind for next time. That being said, even without primer it's a pretty strong joint. But I'd rather do it the right way than the easy way. :thumbsup:
 

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A big benefit of angled baffles is it doesn't transmit nearly as much energy into the door panel, because the movement of the cone is no longer perpendicular to the door panel/skin. This can significantly reduce vibration and rattles.
 

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Discussion Starter · #15 ·
In theory. Although if you were like this one person who somehow managed to muscle his door card back on despite one of his two brackets not technically clearing, you might find the opposite to be true.

That unnamed person...

<---(Hint hint)

...still needs to fix this problem. :p
 

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I'm curious to see how changing the angle of baffle would not reduce vibrational energy that gets transmitted to the panel.

Granted I haven't tried it in a door, and where I have tried it isn't really fair, but part of the reason I bolted my kick panels to all 3 panels in the corner of my kicks was because of a couple of FEA sims my dad put together on just this while we were still on talking terms. The sims showed vibration reducing as the angle increase, up to 45 degrees. He modeled 0, 15, 30, and 45.

I guess I can always try it myself and measure it in a few weeks once CLD testing is finished with the CLD test rig, with some modifications.
 

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I'm curious to see how changing the angle of baffle would not reduce vibrational energy that gets transmitted to the panel.

Granted I haven't tried it in a door, and where I have tried it isn't really fair, but part of the reason I bolted my kick panels to all 3 panels in the corner of my kicks was because of a couple of FEA sims my dad put together on just this while we were still on talking terms. The sims showed vibration reducing as the angle increase, up to 45 degrees. He modeled 0, 15, 30, and 45.

I guess I can always try it myself and measure it in a few weeks once CLD testing is finished with the CLD test rig, with some modifications.
 
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