Dayton 18" HO Ported Build Thread

[Rob Harrison]

I'm finally getting around to providing the documentation of my build based on TLS Guy's design and Haoleb's build. I tried to educate myself and play with various online sub calculators, bassbox pro, and WINisd pro. Ultimately I found using a larger box.. around 8.5 cubic feet and tuning it to 19 hertz produced a flat and deep reaching curve on WINisd pro. I also researched the vent calculators and found the article by Troells Graveson I posted above, where he varied vent lengths and measured responses to back calculate and verify the vent calc correction factors. HIs findings were that the vent lengths are calc'd too long using the normal methods. I applied an average correction based on his findings and arrived at a vent length of approx. 26" to tune the 8.5 cubic foot box to 19hz.
I've not measured the response with microphones and such... but the performance of this sub is extremely pleasing. I'm amazed with it... and so are my friends.

Anyways... attached is the design... I did modify it a bit as I went. I've not gone back and updated the design drawing, but the main difference is that I doubled the bottom by using two panels of 3/4" MDF. The pics will show this... pics to follow....

 

[Rob Harrison]

The sub finished.... except I'm contemplating a grill. Can't stand the waffle grills I used on my car subs when I was a kid... I"ll post more on the grill if I ever get around to making one. Also included one pic to show the interior bracing.....

 

[Rob Harrison]

I start by whittling down the large MDF panels using my circular saw and a clamping straight edge. I usually go a bit big and then perform fine sizing on my table saw.
I really like these clamping straight edges...

 

[Rob Harrison]

In these next pics, I've dry fit the back onto the bottom panel. You can see how I used the doubled panel for the bottom... it creates a nice rabbet joint, lots of glue surface. You won't see it in these pics, but I used biscuits all the main panel joints, dados for all the internal braces.

PIcs also show the layout and dado the bottom for the vent ribs and dry fitting the ribs prior to gluing. The center vent rib is also the primary vertical brace for the back panel.

 

[Rob Harrison]

Here are multiple pics showing the bracing. None of the braces are glued I these pics, other than the central vertical brace that is also the central vent rib. All the pieces are placed into tight-fitting dado joints for these pics. Again... I'm only making a dry run. Later you will see pics of the final bracing after I've rounded all the corners/edges (not in the glue joints). Seems to me the movement of pressure waves would be less disrupted by rounding over the sharp edges of the exposed bracing. Is this a silly extra step or not????

 

[Rob Harrison]

Dry fitting all the sides. Detail showing how the bracing is installed.
You can see the detail on how I made the baffle double thick and joined it with the sides, similar to how the side and back panels are joined to the bottom panel. Again... I used biscuits to help with alignment during gluing as well as providing strength to the joints.

 

[Rob Harrison]

Cutting the hole in the baffle for the driver. I use my own version of Jasper jig... it's a piece of plywood or Masonite that I fit to the base of my router and then drill holes at the appropriate radius and use the drill bit as a pivot. Works like a champ... infinitely adjustable by drilling more/different holes... etc. Okay.. not infinitely adjustable, but more than adequately adjustable!
To cut the primary hole, I make successive cuts with a straight bit, going deeper each time until I'm left with maybe 1/16" inch of material. My jig saw makes quick work of this...
Then finish the hole with a laminate trimmer.
To get the recess for the driver I used a rabbetting bit with a bearing that happened to be the right size for the driver flange.
Had my rabbetting set not been the correct size, I would have created the flange rabbet with my straight bit and my hokey jasper setup before cutting all the way through the baffle.

 

[Rob Harrison]

Photos of the gluing process.... The trapezoidal shape of the base made for some fun. Clamping against the angle needs some extra love.... I use wedges to present a flat surface to the clamp face. Works for me. Probably a million ways to do it.... whatever works for you. BTW>... the old adage about clamps is true... seems like I never have enough. The big ones are expensive... I'd really like to have about 4 more 48" Bessey K clamps (they are the clamps with the substantial red clamping mechanisms.... the bar clamps I use (silver with blue anodized aluminum parts) are from Rockler. I really like these... much better than a typical pipe clamp. Not as expensive as the Bessey clamps... but not quite as nice as the Besseys. (If my wife is reading this, xmas idea for you honey!)

Note that I"ve used the dados and biscuits for joinery. I like having the surface area for clamping and both of these also help with aligning the parts during the gluing. I always get a bit anxious during a glue up session... seems like I can never work fast enough... I run out of glue mid way and have to find a new bottle..., I have glue on my hands and have an itchy nose.... my phone rings.... parts seems to slip and slide all over the place.

That's why I like biscuits... they really help maintain the alignment during glue up.

Also note that I've rounded over the exposed corners of the bracing.

 

[Rob Harrison]

More glue up photos....

BTW - I'm using titebond II for most of this. I used some polyurethane in places... can't remember why or where. But in the spirit of full disclosure......

Included some shots showing the bracing after I have the top on.

 

[Rob Harrison]

Forgot to mention the sanding and routing of all external corners. I used a 3/8" roundover bit and sanded to 200 grit using my random orbital sander. I needed a bit of wood dough in a few spots here and there... Also forgot.. I made the top and bottom slightly oversized. After finishing the gluing, I trimmed the top and bottom with my laminate trim bit. Left a perfect seam!

Mounting the woofer.... This is a time to be meticulous. Go slow. Careful.
I used the woofer to mark the hole locations. I used a Vix Bit to drill partial pilot holes... If you aren't familiar with these... become acquainted. I use them quite a bit... door hinges, blinds and curtains, coat hooks, etc. They automatically center the drill bit in the screw hole of the object being mounted. They worked great for centering the screws in the woofer's mounting holes.

I then moved the box to my drill press to finish the holes. Given the minimal amount of material at the edges of the woofer cutout, I wanted to make sure the holes were accurately installed and perpendicular.

I used black oxide coated cap head screws, 1/4-20 thread, and I forget the name of the threaded inserts. I bought the inserts from Mcmaster Carr. They are the version with the flange/stop. Mcmaster's screws were kinda spendy and sold in boxes of 50.... I think I ended up getting just a dozen from a third party retailer on Amazon. They are finished nicely...

I used a pair of gold plated binding posts from Parts Express.... rattle can truck bed coating over automotive gray primer.

 

[Rob Harrison]

So there you have it. Documented build of my theater sub using a Dayton Audio RS466HO-4.
You will need two full sheets of MDF to make this. There is some waste, but considering a sheet of MDF is coming in around 90 pounds, I'm thinking the sub box weighs around 140 pounds, add the woofer weight Which I think is around 60 pounds... total weight is coming in around 200-ish.
All told... I love this project and the outcome. It exceeds my expectations. When your outcome exceeds expectations... you gotta be happy. It is head and shoulders better than my servo-controlled velodyne 15" powered sub.

I highly recommend building one.... just do it.

 

[TLS Guy]

Very nice build!

 

[JohnnieB]

Thank you for sharing Rob. Looks great.

 

[annunaki]

Yes agree with others. Great build and execution!

Nice job!

 

[Haoleb]

I'm not sure who the moderator is for the DIY forum but if one of you guys could somehow unlock my previous posts in this thread I will go through and fix all of the broken image links. I got tired of paying for a domain and hosting that I was not using so I let it lapse but I still have all the images for this thread saved.. I just can't go back and edit posts that old.

 

[Sean McCormick]

I'm not sure who the moderator is for the DIY forum but if one of you guys could somehow unlock my previous posts in this thread I will go through and fix all of the broken image links. I got tired of paying for a domain and hosting that I was not using so I let it lapse but I still have all the images for this thread saved.. I just can't go back and edit posts that old.

BUMP, can a mod please let him post pics? I'd love to see this build! OP, is there any web server link you can share to see the album those pics came from in lieu of the mod unlocking your posts?

 

[rojo]

BUMP, can a mod please let him post pics? I'd love to see this build! OP, is there any web server link you can share to see the album those pics came from in lieu of the mod unlocking your posts?

Archive.org for the win! <-- click that.

 

[Sean McCormick]

That is way cool! Thanks for the link! Good to know for other old and broken picture links!

 

[Raymond Leveritt]

So here are some photos of the box design. The total outside dimensions of the box are as follows.

24.5" Wide
27.5" Tall
34.5" Deep

The port design I decided on is basically a complete self enclosed port inside the box. Meaning it does not rely on the bottom or back panel as a port wall. This makes it stiffer and allows me to move the bottom of the port cutout up from one inch from the bottom to two inches.

Also the port length is exactly the specified length of 37.29" when measured from the face of the front baffle to the opening inside the box. Measured along midway of the port (1.5" down the 3" wall)

The port itself is 3" tall by 14" wide inside dimension.

Good Morning, I cannot see the pictures and I would really like to. What do you know about that? Thanks, Raymond

 

[Raymond Leveritt]

Good Morning, I cannot see the pictures and I would really like to. What do you know about that? Thanks, Raymond