Taking my 15" DIY subs to the next level.

ACI had a weekend sale back in the summer and I was lucky enough to grab four 15" sub drivers from them. They're pretty nice looking units that were used in their Maestro subwoofer. But they stopped making the Meastro and sold the remaining drivers for a great price.




I wanted to do something that looked a bit nicer than my last subwoofer build so more time was spent designing the enclosure and a lot of time experimenting with the final finish on spare wood prior to the build. I figured out a method that will allow anyone to get a mirror shine without any hard work......no sanding, and best of all, it can be done in your own living room.

Yeh, I know that sounds hard to believe. But just to keep you interested, I'll post one of my experimental boards. Now this trial actually had 2 experiments going. If you look close on the right side reflection, you can see some roughness, that was the other half of the board.

I didn't really need a super low tuned subwoofer, I figured 17hz-18hz was fine for me. After running the specs, 6.5 cu ft looked okay. After talking to Mayhem13, he figured I could go as small as 5.5 cu ft. So i figured 6 cu ft tuned to around 17.5hz with dual 4" ports would be nice.

These 2 enclosures are being built with 1.25" worth of birch/baltic birch plywood. Top and bottom are actually 1.5" and the baffle is 1.75" because of an extra piece of mdf.

The cut list will be posted later because I remember last year before my first build, I was looking everywhere for a cut sheet I could use. So it may help someone eventually if I post it.

But for now, on with the build.

I marked where the braces would be going inside the enclosure and then glued small pieces of wood along that mark so it would be easier to line everything up during the build.






As you can see, this made it much easier to line up the braces, plus gave them a little more gluing surface. This is showing the first layer of birch.






These hard plastic 90 degree squares are nice and can be bought at Rockler. They came in handy for perfect angles. You can clamp the wood to both sides of the square if needed and it will hold nice and secure giving a perfect angle. It's hard to see, but I did leave about 1/16" overhang to grind off later with the flush trim router. In hindsight, that could have been left out because i covered the whole box with another layer of baltic birch anyway.

Yep, it's the truth! I'll post more about it later.


Alright, so here's the boxes after 1 layer. I believe the bottom box was just glued in this photo so I stacked some weight on top. Yes, that's an old stripped sub box I had build for me back in the 90's.......now being used for weight. I did throw it away a couple days after it served it's purpose though!






And yeh, I figured the drill press on top of that would add just enough weight to get things done like a professional. Had I not used the extra weight of the drill press, have no doubt, this whole build would be worthless. So never forget to use spare heavy tools versus lifting weights from the weight bench.

Just in case no one has ever seen a hole being cut, I give you a cut hole photo:




I'd also like to pay tribute to my smaller circle jig that got destroyed during this build. The pin in that one always seemed real tight and as I lifted it out of the wood. The plastic cracked right where it was screwed into my router and actually fell off. I do have a tendency to over tighten screws, so I'm guessing that didn't help much either. Regardless, after it broke, I got aggravated and found out that it flies pretty far when you throw it like a frisbee. It's somewhere in the back yard. If I don't find it by spring, the mower surely will.

After the first layer, I had to flush trim the sides all around. Then I rolled wood glue on each panel and put a 1/2" layer of baltic birch on top of the 3/4". I guess the 3/4" would have been fine, but the box felt too light compared to my mdf enclosures, so I figured why not beef it up a little more. After the 2nd layer, I had to flush trim all the sides again.






And here's the box with no roundovers yet. As you can see, I did add braces in between the other braces....beef it up.







Next up.....freehand routing with the humongous 1.25" roundover bit. Did anything break, did any animals get wrapped up in the spinning blades? You'll have to check back later to find out.

Gloss finish method is coming, don't worry!

The big ole 1.25" roundover bit is so large that you need to either make or buy a base that it will fit through on the router. I chose to make my own......the fun/scary way of course.

I had an old Craftsman base that was pretty much worthless. It was about 1/4" thick plastic, but the through hole for the router bit didn't fit. Easy to fix though, check it out:




Ha, I put the bit in the router, then just slowly......slowly adjusted the base level up. As the spinning blade came up, it chewed through the plastic. Yeh, it probably wasn't the "right" way to make one, but it was a bit more fun having plastic flying everywhere.


And here's the edges afterwards: No lives were lost, no injuries either. It actually went just fine.

I wanted to have the top and bottom pieces wider than the box itself. Sort of like a table top, but with only about 1/2" over hang all around. I also wanted an extra piece on the front baffle for flush mounting everything.

The top and bottom pieces are 3/4" mdf and the front baffle cover is 1/2" mdf. I have some more good news in prepping the mdf for paint (this is not for the mirror coat stuff mentioned above). I've used a lot of different primers on bare mdf and it takes many coats to seal it up. I've used diluted wood glue to seal the mdf before primer and still needed 2 coats.

Well, I just happened to stumble across this Krylon rust primer formula:





BARE MDF, no wood glue sealer......1 coat of this primer did the job. That's no joke. And this stuff came out of the can like no other spray can I've used. Very good pressure and it lays down some serious coverage. Matter of fact, on my front bare mdf baffles, after 1 coat I was ready to paint. I barely had to sand anything at all. But I had them standing straight up while painting.

On the tops and bottoms, I laid them flat which didn't give me nearly as nice of a primed finish because of how I held the can. BUT I still only needed 1 coat, I just had to sand it more than the baffles.

1 coat on bare mdf: It wasn't quite dry yet in this photo, but you get the idea.






You can see that small piece of sandpaper laying there. That one side of paper is all I used on both front baffles (not pictured). Literally 30 seconds on each one was needed if that. I found the stuff at Meijer's. It's like a Walmart, I believe they are nationwide. Not sure if HD or Lowes carries Krylon.




Stay tuned for a way to put some cheap feet on your subs.

Sorry I let this thread dry up, I was busy with the next project.

On with this build. Keep in mind, the following parts only got spray paint, not the piano finish.

I needed some cheap feet for this beast, there were some nice looking kitchen drawer pull knobs at Lowes for about $1.50 on clearance. They turned out better than I thought. Photos of that DIY portion may come later.

Here's the second 3/4" layer that will be glued to the bottom of the subwoofer. Notice I didn't need to spray much towards the center because you'll only be seeing about 1/2" of the edges. My trusty cabinet door knob jig was used to mark where I wanted my feet to be.





Next up was a forstner bit in the drill to countersink a hurricane nut so that it was flush with the mdf. I did that because it is going to get sandwiched between the 2 bottom layers. Some "Goop" glue was added to hold them in place just in case.




The only thing you'll see when this piece is glued on the bottom will be the roundover portion.

Sorry, but I've got to jump pretty far ahead here to get this finished up. No need to post photos of my baffle cover and all that. On with the finished product.

A little detail about the finish that I've been talking about. Lots of testing was done to get this right. It's very easy to get the 100% smooth mirror finish and I will show that later. But I realized that these subs were going right next to my screen and when I put my sample of 100% gloss pieces next to the screen, they acted like a mirror.....literally. So I had to use the same product to finish the subs, but try to give it some texture. The gloss is still there as you'll see. Don't worry, I'll describe how to go from this finish to a mirror when I'm done here.


Here's a close up of the finish texture that my friends liked better than the "mirror" (this could be considered harder to do actually). I glued the veneer over the roundovers, and marked where my front baffle was going to stop. I then did the finishing technique up to that tape line.

Leaping ahead. The base and top pieces were glued on as you can see. I made these come out far enough in the front to cover over my extra piece on the baffle.

The tape lines were removed along side the veneer shown in the last picture. Then my extra 1/2" thick baffle piece was glued on. This was mostly for decoration, but it does take the front to about 2" thick I believe. It was mdf for easier painting, the rest was baltic birch.







Pay no attention to the odd looking couches. That's what happened when a past ladyfriend went looking for furniture......yikes. I never go into the room though, so no big deal.

So here's what will blow your mind, this finish was SO easy that I did it right in this livingroom! No sanding either. And that's no joke, even though you're probably shaking your head yelling "LIAR" at the monitor right now! But first, more photos.


Side view:








I really like how the front blends in with the roundovers. This was a little bit of a worry while I drew it out on paper. But in the end, it came out pretty good, at least good enough for me. You can see why I opted for the texture instead of the mirror shine. Next to a screen, it was just too smooth and shiny.......is that even possible? Oh, and that photo was taken before I waxed the sides too!

Next came the polyfill glued to the inside walls. Here's a good tip to keep you from going to the fabric store to find it: those super cheap Walmart pillows are just 1.5" polly batts rolled up in a tube shape and covered with cloth!! You can literally just unroll them right out on the floor. At least with the ones I bought.


Now I had to somehow stuff two 33" long 4" ports in these dishwasher sized boxes. It turned out that I had to assemble each one in 2 sections, and then glue them together inside the box. That's because they were too long at the 90 degree bend to make the swing upwards. No big deal though, PVC glue is easy and fast to work with.


Here's the photo: That speaker wire isn't coming out of the port, it's just laying inside it.








Also, if you look close at the box on the right, you can see where the speaker terminals were added. And I should also make a note that the backs were the first portion I finished. You can probably tell that they're much smoother than the other sides, but still have some texture. I figured that would be enough, but it was still too shiny for me......so I let it be a little rougher on the sides and front.

Oh yeh, big ole dishwashers being finished in the livingroom! Here's a decent shot showing the texture.





And dragging this beast outside to try for a better shot before the drivers go in. Well, I hoped for a better photo, but it didn't happen. They aren't quite this dark, but the texture on the side shows pretty good.






The white stuff on the base is dust from a canvas drop cloth. I used it to help drag the subwoofer through the house! It got wiped off later, don't worry!

Probably one of he meanest comments I've seen on this board Penngray!

Thanks guys, I appreciate the comments.

Here's the final product in place: It's difficult to get a good photo in my basement. Must be something with the greyish green walls I guess.






And the front view:





That's not where I'll be keeping my mains of course. I just sat them up there temporarily. But believe it or not, they don't sound too bad laying like that. Maybe I could rebuild them like the center channel with the tweeter in the middle, I'm not sure.


Later today I'll post details on how I put the gloss finish on my proprietary burl veneer. I might have to take some more photos to show it better.

Thanks LonelyRaven, you're right, I did try and plan it out much better this time than my previous build. Glad you like how it came together in the end.

fj6474, nope, no Saran wrap.

I've got to head out for a while, but I will get details up later. I'll probably just do a sample piece and take photos of the process.

Someone sent me a message asking for the cut list, I'll try and get that posted later as well.