Dayton 18" HO Ported Build Thread

[Haoleb]

Time for another update! I have been hard at it for.. well.. days now. FINALLY got all of my pieces cut but still have a good amount of hole cutting to do with the router and then putting round-overs on those holes. Granted, I have been taking my time and making sure everything is perfectly square and to the exact dimension. But dang there are alot of parts to these cabinets. I can see the value for folks who choose the simple slap it together designs. I think I counted 43 pieces per box.


So far everything is going exactly as planned. I am very pleased with the progress and I am also pretty glad I took the time to design everything using the 3d cad software beforehand because there is no guesswork involved anymore. Its just up to me to make the parts like I designed them

Working on the first main panel brace as I call them. I thought cutting the holes with the router would leave me in a huge cloud of dust but actually its the cleanest process so far considering I can hold the vac hose right on the cut and it just sucks everything right out.

First one completely done! Used a 1/2" round over on the holes and cut my little dado's with a 1/2" straight cut bit in two passes to give me the 1" wide x 1/4" deep groove. Then set up a little jig to cut out the little portion that goes over the top of the port assembly with a flush trim bit.

The other side. No dado cuts. The reason for them in the first place was because originally I was going to use 3/4 thick MDF for these but since I needed to loose some volume I made them out of 1 inch instead but kept my other braces the same as they were with the 3/4" dimension.

The makings of the first "arch brace" 8" hole cut out of it with the 1/2" roundover. Just need to cut it in half now.

twins! only 14 more to make!

Started gluing parts together. I did some research what seems to be the best glue... Some say PL premium... Some titebond... Then there's which titebond. Well I have titebond original. and I bought some PL premium... But in the end I decided to use the Titebond III. I have always used titebond and I don't really want to experiment on this project. I may use the PL to go through everything with a nice bead in the corners to be sure this sucker is sealed but I dont think that will be a problem.

Got the first port in the clamps as well! These parts I glued and screwed. I just like to add screws to certain parts. Again... I did alot of research on the best screws for MDF. Consensus was these "confirmat" screws. Basically they act like a metal dowel. You use a special countersink/drill bit that drills deeper than the actual screw and also ensures the head of the screw does not volcano out the MDF. I got the "firmit" generic screws that are the same thing from my local rockler store and got the countersink bit from amazon.

Special countersink.

"firmit" connecting screws. These are the 7x50mm that I am using.

 

[TheWarrior]

Keep it coming! (I wish had a bigger garage!)

 

[chucksrt]

Awesome build! I have never seen these fasteners before but i am going to have to stock up. Keep it comming!!!

 

[walter duque]

For passive subs this is not a bad amp http://www.amazon.com/QSC-GX5-500-Watt-Power-Amplifier/dp/B0018D84YC
Now this http://www.abamps.com/amplifiers.html#800-2 amp has the same power rating but sounds a little better, so I think or imagine anyway.

I own both, the QSC is not a bad deal.

 

[Haoleb]

Well things have slowed to a crawl. Now that the holidays from work are all over with its back to the grind. I am also doing some moonlighting at a former employer after my regular job gets out so it doesn't leave much time to work on things I actually want to be doing.

I do have the ports glued up to the point where I need to paint the inside of them before I put the tops on them otherwise it will be hard to do later on. I also am working on gluing the bracing up one piece at a time. Very slow. I do however have EVERYTHING finally cut, routered, rounded over... I am sure my neighbors just loved listening to me cut holes all day sunday... If only they knew what I was working on! Then they would have a reason to worry.

Also the first of two drivers I got had sort of a bent frame when I inspected it so I contacted parts express and they had me send it back. I am still waiting on the replacement. I have been told it should ship by tomorrow. Today I received the second driver which I ordered. And again same story the frame is slightly bent upwards in one area. The first time they said it was shipping damage. Now I am convinced its a defect with their casting because it is exactly the same. Its bugging me but I guess I will just have to live with it. I doubt it would even be noticeable once the thing is mounted and I can't see it affecting sound quality but it still bugs me. I have sent them detailed photos and a description of my findings urging them to inspect a new driver off the shelf. We'll see what they say.

Guess I better get to it and glue something else together. At this pace I think sometime in February looks like a decent timeline to get them fired up. Really sucks to spend my whole day staring at the wall for 8 hours at work because they can't keep me busy when meanwhile I have no time to do other stuff.

 

[ARES24]

There is always the option of going without sleep

 

[JohnnieB]

Hey Haoleb, looks great so far. I do have one curiosity. Why did you not dado both sides of the main panel brace?

 

[lsiberian]

This is really coming along. Can we get this thread stickied?

 

[Haoleb]

Hey Haoleb, looks great so far. I do have one curiosity. Why did you not dado both sides of the main panel brace?

I don't know. I could have. I just didn't. The only reason I did the dado cut in the first place was because i needed to shrink the thickness of that panel because I did not want to go back and re-draw other parts in the 3d Cad. I could have just as easily cut 1/8" deep dado on each side. Or 1/4 on both sides and lengthened the arch braces...

Now that I have been assembling it I can see this design is not really something I would recommend for a first timer. Even being as precise as I possibly could if a few parts are 1/32 long or short by the time you add those parts up it creates a less than perfect fitment.

I will have to snap some more photos this weekend when I get a chance since it is starting to look like something now.

I also have been in contact with parts express about my drivers and they have sent a replacement for the first one that came that was bent and ups picked up the second one that came bent today. They are still firmly saying its shipping damage so I will just have to wait and see if the replacements are the same or not. Fingers crossed!

 

[JohnnieB]

Thank you. I suspected this was how you adjusted the final cabinet volume. I will keep this in mind.
Looking very nice. Very well done so far.
Sorry to hear about the driver baskets. I should re-inspect mine as well. Its been sitting on the porch just waiting.

 

[Haoleb]

Time for a few more pics! I got the first port glued all up and glued down to the bottom panel. Once the last couple parts dry I will roundover the inside opening and then I can attach the rear panel.

Bracing for one sub as complete as I will assemble it before it goes into the cabinet. After that I can assemble the rest of the parts and adjust them for proper fit if needed.

Arch braces

This is the rear of the top panel of the port. Rounded over with a 3/4 roundover since this edge is exposed in the port.

The black paint I used for the inside of the port is rust-oleum ultra cover satin black. I am actually pretty pleased with the finish when using a foam roller. Last time I built my subs I painted them with a professional HVLP unit but Since I don't have that luxury anymore I think its down to a roller finish. I was thinking duratex but I don't really care for the textured finish. I might just go get more of this rust-oleum stuff and roll it on. Using the foam roller gives it a slight texture that helps hide the "endgrain"

Glued and screwed the top port panel on with 5 screws on each side down the length. I used the PL premium on these joints since it is less messy and the joints were not perfect enough. You can tell where I used the PL because it turns the MDF dark anywhere it touches. I used a bunch of the titebond to glue the port assembly to the bottom panel and simply set a bunch of the other cut MDF on it to keep pressure until it dried.

 

[Haoleb]

Well progress has been slow, But I have just a few more parts to glue into one of the cabinets then I can start attaching the sides and front panels.

I also received both of my replacement speaker drivers from parts express. One arrived perfect and one arrived slightly bent again. They have been outstanding in their customer service and trying to get me drivers in perfect condition. The replacements I got both had extra packaging and care but UPS still managed to hit one hard enough to bent it slightly. I emailed them the details and said I do not want another replacement. Once I get the driver installed it shouldn't be noticeable. They could improve the packaging but as I said their customer service has been great.

So.. pics. That's what you're really here for anyway.

Port assembly glued to the bottom and now gluing the back panel on.

put a 3/4" roundover on the port opening and painted. I could have rounded over both edges sides but figured it was not necessary.

First sub starting to come together with most of the bracing glued in.

This thing is starting to get heavier and less manageable with every part I glue on.

 

[Haoleb]

Update... progress is still very slow. The last couple days I haven't even had a chance to touch the subs but this weekend I plan on getting something accomplished. I am hoping to get one subwoofer fully assembled and ready to start painting and the second I plan to get to the stage the first one is already at.

Ready to attach a side panel

I am still not sure where I am going to put the rockwool insulation. Possibly line the side walls with it I am thinking.

Gluing and screwing on the first side panel. I screwed the middle of the panel into the main panel braces with three screws each. Had to get a few more pipe clamps to make sure everything fit together nice and tight.

Both sides attached. Now it is starting to get pretty heavy. Between the size and the weight it is becoming quite a chore to move it around. And I still have three panels and the driver to add.

The glue going all over the place is not exactly pretty but some of those areas are getting hard to reach to clean up the excess. And excess there was. Don't want to starve any joints for glue now do we.

The threaded inserts I got from McMaster-Carr to attach the driver. 1/4-20 screws. The 1/4-20 just barely fits into the holes on the driver. I will likely have to run a drill bit through them to take off just a hair. They go in if I turn the bolts but they do not go in by simply pushing. These inserts were the longest ones I could find and also have a small flange to help in strength. I also will apply glue to them when i screw them in. I picked up what is basically super glue made for woodwork that some folks seem to use in MDF. It is very thin so it should flow into the hole very well.

Of course I will test a couple before trying it for real just to be sure it goes as planned.

 

[Haoleb]

Well the CA thin stuff is definitely a no-go for this purpose. It soaks into the MDF real well but just not thick enough to adhere to the fastener. Got another one with PL drying. See how that holds. They would be plenty strong without any glue at all but I don't want just strong enough. I want indestructible!!

 

[ARES24]

There are some pretty impressive epoxy's

 

[Haoleb]

More progress!

Speaker hole cutout in the front baffle and recessed for flush mounting! The jasper circle jig I have only goes to 18-3/16 with a 1/4" bit which is pretty much exactly what the driver measures... SO rather than have it end up being too tight I just threw in my half inch straight cut bit and used the 18" hole giving me 18-1/4 recess. Used calipers to measure the thickness of the flange and set the depth stop for that perfectly flush fit

Next up was drilling the holes for the inserts. I don't have a drill press but I do have access to one so rather than drag the whole baffle to the drill press I used it to drill some holes in a scrap piece of MDF and then used that as a guide to keep the bit straight. Worked great.

Because of the thickness of the baffle I then had to recess the inserts a little bit. I could have got longer bolts but did not want to do that. Since the hole was already drilled and the cleanest cutting drill bit I have is a forstner bit (which requires a place to center) I used the router with that 1/2" straight bit again and plunged it down to create the recesses. The bonus here is now I have a small pocket to fill in which will seal the bolt holes from allowing air leaks.

After the holes were drilled and recesses cut I rounded over the back of the baffle with the 3/4" roundover. There will be a large amount of air rushing past this area coming from the cone.

Inner baffle glued in and the port cutout with the flush trim bit after the glue dried.

Next up was gluing on the outer baffle. This meant covering both surfaces with wood glue. I did not want wood glue dripping down the port so I cut a piece of foam and stuffed it in there to contain the squeeze out.

Gluing on the outer baffle. I used 3 of the same size drill bits I drilled the insert holes in the baffle with to line up the holes once again for perfect alignment since I had the two baffles clamped together when I drilled them but needed to attach them to the box one at a time.

Front baffle glued up and again the port hole cut out and rounded over. Now Is when I screwed and epoxied in the threaded inserts for the driver. I installed the bolts so that I could see how straight they were going in and make corrections. Worked great. I decided to use 2 part epoxy after testing with the CA, gorilla glue and the PL premium. Figured the epoxy would hold the strongest and did not really think of epoxy until Ares Mentioned it.

Nice thing about this stuff is it has the mixing tube so there is no messing with mixing it and then having to try and apply it. But of course you waste half the darn thing in the tube. Half for this sub half for the next one I have used this stuff in the past and it is pretty strong.

Wanted to test fit the driver and screw it in just to be sure everything lined up perfectly and was going to be no problem before I get the cabinet too far done to fix a problem. The bolt holes in the driver are just simply too small for 1/4-20 bolts. I ran the 1/4 bit through them and they fit better but unless the alignment with the bolt holes is absolutely dead on and perfectly squared it was a little too tight for comfort. No problem. I ran a 9/32 bit through the holes to open them up another 32nd. Much better fit. Also when bolting them in I will use a little thread lube just because it makes the threads go in so much smoother.

Luckily all my holes line up fine and everything fits perfect. The way that the driver was made the holes in the rubber surround do not line up perfectly with the holes in the cast frame causing the bolt heads to smoosh over the rubber in a few holes. But... that's what I get for being a perfectionist.


I currently have the clamps back on the box attaching the rest of the bracing that attaches the front baffle to the rest of the internal bracing. A couple more days and I will be putting the top on and starting to get it ready for paint.

The other one is much further behind. I have only today attached the rear panel to the bottom panel/port which I had already glued up.

I must say thing thing is turning into a BEAST. I can no longer pick it up. Just too big and too heavy. And that is without the top or the driver. It really is obscenely big compared to most commercial subwoofers. And built like a freakin' tank.

Thats all for now. Until next time.

 

[ARES24]

It's a good thing that you made the driver hole a bit big, paint takes up more space than I would have thought it does. I made my hole about 1/16" bigger then needed and after I painted the driver is tight and difficult to remove.

 

[JohnnieB]

I can see I may need a few more clamps.
Lookin' good H! I'm anxious to see the finish.

 

[lsiberian]

I can't imagine moving that thing. That's why I use plywood(stronger and lighter) I know it costs a lot more and requires more expensive blades and bits.

I never really have seen someone use epoxy. I normally use PL construction adhesive or titebond. I'd be interested in hearing why you went the epoxy route.

From a design standpoint is the reason you went with mdf bracing rather than oak simply a matter of cost. I've found bracing with oak to be very effective in my builds and much easier to work with.

It's cool too see someone build something with very different techniques. I never even though of building a slot port separately and then attaching it into the box. That's so clever. Everytime I think about doing a slot port build I always worry about that getting the slot onto the box exterior. Now I may give it a go with that technique.

I know your pain of lining up drivers and screws. I confess I just use screws. I hate working with threads and t-nuts. Kudos to you for making them work. I'm sure you are eager to get this thing to a test phase.

 

[lsiberian]

I can see I may need a few more clamps.
Lookin' good H! I'm anxious to see the finish.

You can never have too many clamps. Corner clamps are probably the most useful ones I own. I suggest at least 8 of them.