Me documenting my Dayton 18-22 cabinet build and thanks to...

[moves]

First off, big thanks to Loveinthehd, TLSGuy, Verdinut, and everettT (Never noticed the 3rd 'T,) who were the main dudes, or dudettes, who helped me get off me feet. For the noobs that have the same type of questions regarding the Dayon 18-22 cab build, take a look at the following thread. It discusses amplifier selection, DSP, cables and connections for this driver. https://forums.audioholics.com/forums/threads/hsu-vs-jtr.111952/

The plan I got from the driver supplier was sized at 3.8 or so c.f. without braces. So I decided to just copy the Parts Express Box and watched their you tube video and figured out the dimensions and assembly procedures. I am using 1" MDF instead of the Parts Express 3/4" MDF. I am also using 3/4" plywood for the braces. So for, I have everything cut and now just have the cross brace left to do. I'll likely get that done this week. I'll try to keep posting updates for whoever is interested.... I like to hear some feedback on the goods and the bads of what I am doing.

Cheer!


Below are some pics of a dry fit with some braces: I am about a month in.

 

[moves]

I will glue the centre brace tomorrow

 

[Alex2507]

I like everything about the 1" MDF except the weight. The rabbeted corners are a new approach that looks interesting. Keep the pic's coming por favor.

One thing of some concern is mixing ply with mdf. I believe JL Audio had something on their site saying to use the same material for the braces that you use for the cabinet. The details escape me. The other thing I remember is that they said not to use particle board. I've broken both those rules on the same build without hesitation or regret, FWIW.

 

[moves]

I like everything about the 1" MDF except the weight. The rabbeted corners are a new approach that looks interesting. Keep the pic's coming por favor.

One thing of some concern is mixing ply with mdf. I believe JL Audio had something on their site saying to use the same material for the braces that you use for the cabinet. The details escape me. The other thing I remember is that they said not to use particle board. I've broken both those rules on the same build without hesitation or regret, FWIW.

Hey thanks for the comment. I've read that it is better to use plywood (not particle) board because it is more dense than MDF (not particle board). Ill be glueing the sides on today... stay tuned for some pics. I have read that many hardwoods are not sound friendly. Some are.... the species escapes me but I know Cherry was included. However, I am trying to save cost here

 

[Verdinut]

Hey thanks for the comment. I've read that it is better to use plywood (not particle) board because it is more dense than MDF (not particle board). Ill be glueing the sides on today... stay tuned for some pics. I have read that many hardwoods are not sound friendly. Some are.... the species escapes me but I know Cherry was included. However, I am trying to save cost here

No, plywood is not more dense than MDF. Medium Density Fiber is heavier than any plywood, even the baltic birch plywood. The article you read is all wrong.

In my opinion, MDF is the best material for building speaker enclosures. Second best is the baltic birch plywood which is more expensive and unavailable in some areas.

 

[KEW]

Hey thanks for the comment. I've read that it is better to use plywood (not particle) board because it is more dense than MDF (not particle board). Ill be glueing the sides on today... stay tuned for some pics. I have read that many hardwoods are not sound friendly. Some are.... the species escapes me but I know Cherry was included. However, I am trying to save cost here

Cherry has a pretty nice, tight grain, but it is still not as good as MDF!
The problem with any solid wood is that there is a direction to the grain which causes the material to have different properties in different directions.
If you look at a simple, old fashioned yardstick, it is actually pretty durable because the wood grain is aligned with the 36" direction, but I think everyone intuitively recognizes how fragile it would be if the grain was oriented to to run perpendicular to the length (the 1-1/2" direction) or even more ridiculous, in the direction of the ~3/16" thickness (so end-grain is on the printed surface). But wood of a certain length will tend to resonate at a certain frequency.
Furthermore, the amount of contraction/expansion from exposure to humidity is about ten times as much across the grain as it is along the grain. Think of the grain as a bunch of straws which as they get wet get fatter and the shrink when they dry; however, the length barely changes. For this reason, it is critical that you match an end grain edge to another end grain edge and side grain to side grain. Otherwise seasonal reactions to humidity can cause wood to split if it is glued to another piece of wood that expands at a different rate. Not as big of a problem now as it was before AC, but it is still common to see humidity fluctuations between 30% and 70%.
Plywood addresses these issues by alternating grain directions (and there is a fair amount of internal stress and often some splitting of the layers) which makes it more stable overall.
MDF completely eliminates the grain structure, giving a consistent and largely inert cabinet material, making it the preferred choice, especially given the low cost.

 

[lovinthehd]

Plywood's advantages are lighter weight and strength (and somewhat less messy dust when cutting), why you'd not use mdf for touring speaker cabs....

 

[moves]

Thanks for your replies The plywood was easier to work with anyway because of the dados. The 3/4" dado was a touch too small with the 3/4" MDF that I was thinking of using for the braces. The braces are 3/4" but the side walls are 1". The plywood has some give and is probably 11/12" so it fits nice. I am glowing one side at a time and just using the dry side as a support for now. I'll do the other one tomorrow.

 

[moves]

No, plywood is not more dense than MDF. Medium Density Fiber is heavier than any plywood, even the baltic birch plywood. The article you read is all wrong.

In my opinion, MDF is the best material for building speaker enclosures. Second best is the baltic birch plywood which is more expensive and unavailable in some areas.

You're right sorry. Strong is the word I was looking for.

The only thing I would do differently is to maybe rotate the clamps so they are pulling from different directions but I'll do that on the next panel.

I spent a lot of the weekend researching subwoofer connections and I think will try the one VC per channel approach with the minidsp and see how it behaves. I am sure It will be amazing.

I am just about to start practicing a black high gloss mirror finish on some scrap MDF that I will document. Stay tuned....

 

[MrBoat]

I use plywood braces with MDF because MDF has no directional stability. For a given size, plywood on edge, is way stronger than MDF. MDF, or any of the byproduct sheets, could sag over time. As shown with the cheap sauder type furniture where they try to use particle board on edge as part of the structural support. Fine when it's brand new, but let that desk sit with just it's own weight on itself, and the top will be like an old swayback mule in short order. Industry still tries to arrange particle bit constructions as if the same applies as if it were real wood or plywood, but it never works.

The way to fix that old swayback desk or bookshelf, would be a plywood backer beam supporting the original particle board one. If they upgraded their engineering to include some more noble material with predictable directional stability for it's key structural components, they'd be miles ahead.

 

[moves]

It's coming along... sanded the cabinet and it looks great.. pics to come. I picked up some Bondo that is also good for wood to fix up some of the gaps in the joints so i will do that tomorrow. Pics to come.

This is the glue job for the double front baffle. Laying it on the step ladder worked well so i can get the clamps under it nicely. The 2 X 45ilbs plates is also handy. Stay tuned for more pics to come.

 

[Swerd]

@moves

Your sub woofer cabinet build looks really good. Keep up the good work. And we enjoy the photos, keep them coming.

I noticed the door in one of your photos (post #2). Is your workshop in a basement? Will your heavy cabinet fit through the doorway? Will you be able to carry it up stairs?

I also saw the 45 lb. barbell weight. If you regularly lift them, perhaps I'm worried for nothing .
If not, you might need one of these.

 

[moves]

@moves

Your sub woofer cabinet build looks really good. Keep up the good work. And we enjoy the photos, keep them coming.

I noticed the door in one of your photos (post #2). Is your workshop in a basement? Will your heavy cabinet fit through the doorway? Will you be able to carry it up stairs?

I also saw the 45 lb. barbell weight. If you regularly lift them, perhaps I'm worried for nothing .
If not, you might need one of these.

View attachment 26994

Edit*** oops yes post number 2 is the garage. the rest are in the furnace room. It's actually 2 X 45 lb plates
Ha no no it's only a 4 cf box so me and my wife carry it around the house for various work .... I just finished adding Bondo to the cabinet where there were gaps... the stuff stinks and can only be done indoors because it's winter here. It needs 24C for it to cure. I have another cab to build and I am seriously thinking that I will wait for the summer to put it together. I think I may also wait to paint this one in the summer as well.... spray painting anywhere but the garage may be tricky... The pics you are seeing are in my furnace room so I shouldn't really be painting in there because of the fumes.... I need a heated garage. that's what I need.

Here are some close ups. I change the temperature of the colours to highlight the gaps that I filled.

I think I will go over them one more time and then sand again. I still have to make a circle jog and cut the baffles. Since the double baffles are already glued, cutting the hole will be interesting. I can do it!

 

[moves]

Here is another one: https://drive.google.com/file/d/1EC2TBgX9ge874hHyID0YfBUczjGCie_H/view?usp=sharing

I can't seem to make the file small enough to upload here so I've linked it in from my Google Drive!

 

[moves]

Here are some more pics with bondo applied to the seems and gaps inside and out. The end grain is also sealed for painting.

Here is one after sanding. The other pics are pre sand.

 

[moves]

Here are some pictures of the baffle and the T nuts. (You can see my other thread on installing T nuts because I had some basic questions but I think I have it figured out) The baffle was tricky to cut with the router because I couldn't get through the 3 inches of MDF from one side so I had to flip it over and cut through. It is a touch off as you can see from the pics but I think it'll do. You can see some a one prong over hang because of the mistake from the cut but I used 3 prong nuts for those 2 holes and extra epoxy. It's tight. I still have to cut the perimeter of the baffle to size. Just a couple inches off of each side and it'll fit nice. I'll do that tomorrow and then glue. Enjoy!

 

[TLS Guy]

I like everything about the 1" MDF except the weight. The rabbeted corners are a new approach that looks interesting. Keep the pic's coming por favor.

One thing of some concern is mixing ply with mdf. I believe JL Audio had something on their site saying to use the same material for the braces that you use for the cabinet. The details escape me. The other thing I remember is that they said not to use particle board. I've broken both those rules on the same build without hesitation or regret, FWIW.

Well that is the way I have always done it. Do not use butt joints building speakers.

 

[TLS Guy]

Here are some pictures of the baffle and the T nuts. (You can see my other thread on installing T nuts because I had some basic questions but I think I have it figured out) The baffle was tricky to cut with the router because I couldn't get through the 3 inches of MDF from one side so I had to flip it over and cut through. It is a touch off as you can see from the pics but I think it'll do. You can see some a one prong over hang because of the mistake from the cut but I used 3 prong nuts for those 2 holes and extra epoxy. It's tight. I still have to cut the perimeter of the baffle to size. Just a couple inches off of each side and it'll fit nice. I'll do that tomorrow and then glue. Enjoy!

View attachment 27331View attachment 27332View attachment 27333View attachment 27335View attachment 27336

This build looks as if it is going very well.

 

[moves]

Well that is the way I have always done it. Do not use butt joints building speakers.

Correct! The butt joint will not be as strong. The rabbet is the way to go with dadoing the braces.

 

[MrBoat]

Here are some pictures of the baffle and the T nuts. (You can see my other thread on installing T nuts because I had some basic questions but I think I have it figured out) The baffle was tricky to cut with the router because I couldn't get through the 3 inches of MDF from one side so I had to flip it over and cut through. It is a touch off as you can see from the pics but I think it'll do. You can see some a one prong over hang because of the mistake from the cut but I used 3 prong nuts for those 2 holes and extra epoxy. It's tight. I still have to cut the perimeter of the baffle to size. Just a couple inches off of each side and it'll fit nice. I'll do that tomorrow and then glue. Enjoy!

View attachment 27331View attachment 27332View attachment 27333View attachment 27335View attachment 27336

I just drill the pivot hole for the circle jig thru multiple layers with the stack just clamped together. Then the same center works for all the circle cuts on the pieces individually.

Here, I had the stack just tacked with brad nails in place. The baffles were first flush trimmed and sanded to the sides so the centers would be exact, finished centers. Here I am prying them apart after the outside has been routed.

Nip the brad nails about 1/4" and leave them, and they become pilot pins when you go to put it back together and keeps it from sliding around when you glue it.