Dimensions for sealed 18" sub box - Page 2

You'll be able to get 4 of these boxes for that price or less.

I should look into gluing some up and taking them to the local paint shop. That could be interesting. But they aren't here yet, so let's just see how it goes.

I've been working on a bracing idea, but there hasn't been enough time to really tweak my the system yet. So these boxes are going to be your typical fancy window pane shelf bracing set up that ties all panels together. The problem is how much wood that eats up making a huge square with most of the wood removed from the middle. Ideally they'd be smaller interlocking triangles and narrow beams to save weight and wood, but still give the same bracing power. I'll spend more time getting that right for the next runs.

There's a couple problems with your scenario though. What you were worried about is actually the opposite. The strongest part of a box is at the corners and edges. So in reality, the smaller the baffle and the closer to the edge the driver screws are....the stronger it would actually be, not weaker. The closer you are to corner or angle, the better.

Plus, once the wood is glued, the joint is stronger than the wood itself. The problem would show up with a huge baffle and a smaller driver in the middle of that panel.

Having said all of the, the baffle will be bigger than 20"x20" anyway.

The 10" and 12" sealed boxes were cut last weekend, I just haven't had time to list them yet or take pictures. Those are mdf. I'm hoping they get me a prototype for the 15" and 18" within the next week or so. As soon as I assemble them and everything goes together properly, they will be cut very quickly. I was at their shop last weekend and they said they're starting a second shift for the CNC machine which should really help out.

The first 20 or so will be mdf just to make sure it all works out. But the Baltic birch might also be done at the same time for those bigger boxes.

Things should now start trickling in at a fairly good clip.....finally. Flat packs for Paul Carmody's Swope speaker design are done. And I've got 3 other speakers cut that are waiting for the crossover work to be finalized by the designer. Those haven't been posted yet. I think I've got about 12 different flat packs cut right now with maybe 6 waiting to be done this month. That's not counting subwoofer boxes.

Right after Mother's Day my landscaping jobs slow down a lot and things fall into a regular schedule. All the SEOS speaker stuff should be here around the end of May which means a lot more designs.


And if all goes well.......there should be some interesting sub driver prototypes coming soon. I probably shouldn't say much about that though.

It's taking a lot not to talk about the 18" models that are coming. But I'll bite my tongue for a bit longer to make sure these are really going to materialize. I should know for certain in a couple weeks.

Forum member BWaslo stopped by my place today and I showed him the subwoofer flat packs. He thought they were really nice and easy to assemble. I'll get the photos up tomorrow. I tried to get some this evening, but they didn't turn out very good.

The only thing I need to do is get a price for the packaging material and we're good to go.

I need to get the price for packaging material to figure final costs. Plus the first small quantity I picked up isn't an accurate price yet. I got an email from the CNC guy this evening letting me know I should stop down at their shop to discuss pricing on a larger quantity than I initially got. The smaller boxes are not problem and prices will surely be priced good for how beefed up they are. The larger boxes use more than 1 sheet of mdf, so I'm not sure how that will be handled yet. In the past they have bought 5' x 10' sheets of mdf so that things fit better during cutting. I guess that's what they've been working out.


As you can imagine, I'd like to try and sway them to the cheaper side but I'm really not sure what I should tell them we're shooting for on price. If I recall, they quoted around $125 - $135 last year for Baltic birch on the larger sized 18" sealed box. But that had simpler bracing in the design using less wood.

If they can get us the big 18" well braced mdf sealed box for less than $100, I think that would be pretty good. Less than $80 for the 15", less than $60 for the 12", less than $40 for the 10"????

Any input on that? I'm sort of just throwing out ideas of what I should tell them though. Maybe I should postpone the meeting tomorrow and post photos.


The reason the first ones will be mdf is strictly due to cost and to make sure these go together really easy. Baltic is going to be a decent amount more, so it would be best to make any small changes to the design with the cheaper stuff first. But they're pretty nice and go together very simple.

I've got about 4 different bracing ideas, but the easiest one of those will have to be done later after I work with them on a few designs. Right now I drew them up as your typical "matrix" style shelf braces with interlocking vertical beams pulling it all together. BWaslo and I put one of the bigger ones together well under 5 minutes using masking tape. I was able to pick it up and move it around with only tape holding it together. It was surprising solid for just tape.

They hold together good enough to where a seasoned DIY guy could nearly glue up the entire box and then clamp it all during one session. And that's with a decent amount of bracing. Later drop in the 1st baffle layer after it dries, then the outer baffle on top.

They haven't actually told me prices yet, I'm just guessing. But not sure if the numbers I'd like to see are good or bad yet. I'll get pictures up later today to see what you guys think. I've already got a good starting amount of each size, but they won't mind changing bracing or some other easy stuff if needed.

Main thing is to figure out how to ship these without damage, but I've got some good ideas. Shipping rates were checked as well. Because of all the stuff I helped ship out last year my FedEx rates are pretty darn good. So that will help everyone out. I've also talked to my sister about possibly helping me package these things up if I can't keep up with all this stuff once the waveguides come in. I told her maybe we could add $5 to each of the larger subwoofer flat packs if she could help box them up. She did help on some things in the past for free, but not sure on these heavy sub boxes. I mentioned it to another friend as well and he would help if needed.

My busy season is over in about 1.5 weeks, so it might not be an issue anyway.

Yes, a few are already designed for the SEOS waveguide that's coming. The CNC company scanned in the plastic waveguide and cut me a test box. I could get some of the boxes done without the SEOS perimeter cut in the front if you think the boxes should be made for other waveguides as well.


I sort of wish I knew a price range to shoot for on these larger speakers and subs. The previous flat packs were all small and cheap, so it was no big deal when the price came in at $13 - $20 per box. But I'm going in blind on these larger boxes.

Any price guesses or hopeful ranges would help out. I postponed the meeting 2 days so I can get a better idea.