New sub build. A few questions.

[panteragstk]

Ok, I ordered 2 1262w's from amazon today (prime is a wonderful thing) and am going to Home Depot later to grab a router. I've got a bunch of 3/4" MDF I plan to use for the build. I've got everything planned out, but want some suggestions on how to complete my boxes.

I'm going to do single drivers in two boxes on either side of the front of the room. The plan is to make a 15"x15"x15" box using three layers per side for an internal volume of 1.2 cu ft. With the sides all being 2.25" thick I don't see the need for internal bracing. The only reason for making everything so thick is just because I have a crapload off MDF to use, and if I do a pseudo dado on the edges there will be quite a lot of glue surface to keep things nice and sturdy.

Having said my plan, should I just go the traditional route and do two layers on the baffle, one on the other sides, and then internal bracing, or is my plan ok?

Lastly, I plan to get an xls1000 and run it at 2 ohms stereo for 550w per channel. I figure that will be enough for a 13'x17' room.

 

[ImcLoud]

Ok, I ordered 2 1262w's from amazon today (prime is a wonderful thing) and am going to Home Depot later to grab a router. I've got a bunch of 3/4" MDF I plan to use for the build. I've got everything planned out, but want some suggestions on how to complete my boxes.

I'm going to do single drivers in two boxes on either side of the front of the room. The plan is to make a 15"x15"x15" box using three layers per side for an internal volume of 1.2 cu ft. With the sides all being 2.25" thick I don't see the need for internal bracing. The only reason for making everything so thick is just because I have a crapload off MDF to use, and if I do a pseudo dado on the edges there will be quite a lot of glue surface to keep things nice and sturdy.

Having said my plan, should I just go the traditional route and do two layers on the baffle, one on the other sides, and then internal bracing, or is my plan ok?

Lastly, I plan to get an xls1000 and run it at 2 ohms stereo for 550w per channel. I figure that will be enough for a 13'x17' room.

I like it, I dont think you will need internal bracing at that point, but you are going to have one heavy box.... Plus you box being so small I think you will be OK...

I built something similar, except I used 13" JL audio subs, I did double 3/4 on the sides, I only did 1 X on the inside for bracing and everyone said it wouldn't be enough, but it worked and sounded awesome....
I would go up one size on the amplifier, they are priced really close and more headroom better than none...

 

[fuzz092888]

I like it, I dont think you will need internal bracing at that point, but you are going to have one heavy box.... Plus you box being so small I think you will be OK...

I built something similar, except I used 13" JL audio subs, I did double 3/4 on the sides, I only did 1 X on the inside for bracing and everyone said it wouldn't be enough, but it worked and sounded awesome....
I would go up one size on the amplifier, they are priced really close and more headroom better than none...

Not only more headroom, but the 1500 on up are setup a bit differently internally and it makes them superior to the 1000.

 

[panteragstk]

Not only more headroom, but the 1500 on up are setup a bit differently internally and it makes them superior to the 1000.

I had been considering that so I'll go ahead and add it to the list. Thanks.

 

[panteragstk]

I like it, I dont think you will need internal bracing at that point, but you are going to have one heavy box.... Plus you box being so small I think you will be OK...

I built something similar, except I used 13" JL audio subs, I did double 3/4 on the sides, I only did 1 X on the inside for bracing and everyone said it wouldn't be enough, but it worked and sounded awesome....
I would go up one size on the amplifier, they are priced really close and more headroom better than none...

The weight will suck, but I think it will be VERY solid. I plan to use the same box for some LMS-R drivers from TC sounds that should be able to do very well in the same box. I think the bigger amp will do well with them as well. Thanks.

Another question. Carpet spikes or no? Subdude?

 

[fuzz092888]

The weight will suck, but I think it will be VERY solid. I plan to use the same box for some LMS-R drivers from TC sounds that should be able to do very well in the same box. I think the bigger amp will do well with them as well. Thanks.

Another question. Carpet spikes or no? Subdude?

My personal preference is a subdude or gamma instead of carpet spikes. You can also make your own if you'd like.

 

[lsiberian]

I recommended 13 or 11 ply, but mdf is fine. You should brace your sub and be sure to stuff some rockwool in the back of it covered by cloth of some kind.

I use scrap wood to brace subs but some 1x2 oak is fine too.

 

[Swerd]

Ok, I ordered 2 1262w's from amazon today (prime is a wonderful thing) and am going to Home Depot later to grab a router. I've got a bunch of 3/4" MDF I plan to use for the build. I've got everything planned out, but want some suggestions on how to complete my boxes.

I'm going to do single drivers in two boxes on either side of the front of the room. The plan is to make a 15"x15"x15" box using three layers per side for an internal volume of 1.2 cu ft. With the sides all being 2.25" thick I don't see the need for internal bracing. The only reason for making everything so thick is just because I have a crapload off MDF to use, and if I do a pseudo dado on the edges there will be quite a lot of glue surface to keep things nice and sturdy.

Having said my plan, should I just go the traditional route and do two layers on the baffle, one on the other sides, and then internal bracing, or is my plan ok?

Lastly, I plan to get an xls1000 and run it at 2 ohms stereo for 550w per channel. I figure that will be enough for a 13'x17' room.

Have you ever built a six sided box before? You should plan on making some mistakes. Then that crapload of MDF won't seem so large.

Get a plunge router. It, and a circle cutting jig, will make cutting circular holes much easier.

A box made with three layers of ¾" MDF plus the driver will be extremely heavy – as in get a forklift .

I strongly suggest going the standard route, one layer on all sides with two on the front. You will have plenty of scrap MDF to use as cross braces.

Thick cabinet walls will vibrate less than thin ones, but will still have panels with the same large surface area dimensions, and the same resonant frequency associated with that surface area. Using cross braces makes for smaller panels with a higher resonant frequency. For a sub woofer cabinet, it will be easy with cross braces to get the panel resonant frequency above the pass band of the sub woofer.

 

[panteragstk]

Have you ever built a six sided box before? You should plan on making some mistakes. Then that crapload of MDF won't seem so large.

Get a plunge router. It, and a circle cutting jig, will make cutting circular holes much easier.

A box made with three layers of ¾" MDF plus the driver will be extremely heavy – as in get a forklift .

I strongly suggest going the standard route, one layer on all sides with two on the front. You will have plenty of scrap MDF to use as cross braces.

Thick cabinet walls will vibrate less than thin ones, but will still have panels with the same large surface area dimensions, and the same resonant frequency associated with that surface area. Using cross braces makes for smaller panels with a higher resonant frequency. For a sub woofer cabinet, it will be easy with cross braces to get the panel resonant frequency above the pass band of the sub woofer.

Yes, I have built a six sided box before. If I hadn't then I wouldn't be trying to do this the way I am as I would get frustrated and quit.

I wouldn't even try to do this without a plunge router. Got my eye on a Bosch combo base kit. I do need to find a circle jig though. Quite a few have recommended the Jasper jig so I'll be looking at that one.

 

[Swerd]

Yes, I have built a six sided box before. If I hadn't then I wouldn't be trying to do this the way I am as I would get frustrated and quit.

Good. I hoped you had some experience.

I wouldn't even try to do this without a plunge router. Got my eye on a Bosch combo base kit. I do need to find a circle jig though. Quite a few have recommended the Jasper jig so I'll be looking at that one.

Bosch routers have a good reputation, but I've never used one. The combo model is probably what I'd get too.

I use Jasper jigs and they have worked very well in my hands. There is no reason why a home made circle cutting jig couldn't work.

For cutting circles in ¾" MDF, I use a ¼" spiral up-cut bit. It moves the dust up and out of the groove you are cutting. On my router, a DeWalt, I can attach a shop vac hose. So with that bit and the shop vac, most of the dust is pulled up from the groove as I make the cut. Check if the Bosch can do that.

When I cut MDF, I wear a simple dust mask. I also use ear plugs. Routers are very noisy, and if you also have a shop vac running, it will be even louder.

 

[panteragstk]

Good. I hoped you had some experience.
Bosch routers have a good reputation, but I've never used one. The combo model is probably what I'd get too.

I use Jasper jigs and they have worked very well in my hands. There is no reason why a home made circle cutting jig couldn't work.

For cutting circles in ¾" MDF, I use a ¼" spiral up-cut bit. It moves the dust up and out of the groove you are cutting. On my router, a DeWalt, I can attach a shop vac hose. So with that bit and the shop vac, most of the dust is pulled up from the groove as I make the cut. Check if the Bosch can do that.

When I cut MDF, I wear a simple dust mask. I also use ear plugs. Routers are very noisy, and if you also have a shop vac running, it will be even louder.

Thanks. I'll have to see about the shop vac. I made the mistake of using my table saw inside my garage. Needless to say I had a bit of dust to clean up. I figured I try it my way just to see. I may make one the traditional way too. I just want it to be as solid as possible. For the internal brace, how would you go about building that? Just a solid piece with a cutout for the driver, or something else?

 

[Swerd]

For the internal brace, how would you go about building that? Just a solid piece with a cutout for the driver, or something else?

There are many ways to cross brace a box. Your idea will work well.

With a box where all the sides are the same, you have more choices. Send me a PM with an email address. I'll send you the plans I followed for a 12×12×12 box. It shows the cross bracing with photos and a diagram better than I can describe. You can easily modify it to your size.

 

[armed]

you said youre using 2 3/4 mdf....15x15x15?
you dont need any internal braces for that...
i used to compete for db drag, car audio bass competition..
i would used internal braces if the box is somewhat big..
but for a 15x15x15..i dont think you would need it..
maybe if youre using 2 12s in 1 chamber..thats just me..

 

[panteragstk]

Ooh pretty. Can't wait to see how this goes.

 

[panteragstk]

Progress on the box is good. Easier than I thought. The Bosch router is fantastic when used with the Jasper jig. Cheap Harbor Freight clamps work very well.

 

[panteragstk]

All finished. I've only got 100w going through it, but it is a significant improvement over my previous sub (8" kenwood that is ancient). Box is holding fine. I'm surprised how easy it was to build the box. Lots of glue and clamping. No leakage or signs of the box flexing. I'm going to put more bracing just to be safe before I get the XLS 1500 and push over 700w through it. That will tell me if my box is strong enough. If it isn't, I've got plenty more scrap MDF.

Thanks for all the advice, now all I need to do is choose a finish.

 

[panteragstk]

Tried a few bass test movies and all I can say is for the ~$70 I spend on this thing I can't believe it is as good as it is. With only 100w going through it no less. If you are looking for a budget build that sounds great and is simple to do I can't recommend this enough. Can't wait to get my amp to see what this little guy can really do. I just wish I had a way to measure it to see how the response looks. Oh well.

 

[panteragstk]

Another question. If you were going to use a single driver in a ported config, how would you put everything together? I'm guessing 2 cu ft, but the question I have is how long of a port, what location (front, back), and how large in diameter?

Thanks

 

[jinjuku]

You wouldn't guess. You would model for starters. The box displacement and port dimensions would depend on where you want to gain the tuning efficiency at.

 

[panteragstk]

You wouldn't guess. You would model for starters. The box displacement and port dimensions would depend on where you want to gain the tuning efficiency at.

That's what prompted the question. I would use winISD to model right? Any directions you could point me to? Last time I used winISD I didn't do something right, or I just didn't have all the information.