Building a powered sub...

[PoorManQ45]

I'm making this thread to hopefully one day have someone gain a bit of knowledge, and save quite a bit of money compared to purchasing an already made, and inferior subwoofer.

Here's the part list, everything but the MDF is coming from partsexpress:Dayton 15" MkIII subwoofer: ~$160Dayton 1kw plate amp ~$300 : I may Use Beringer EuroPower Amp($250) or 250w Plate Amp($125)(2) 3in Flared ports: $15 each(1) 3/4in MDF: $22 each

External Dimensions(not including covering):24 length24 width30.5 height

Individual panel measurements(number of each will be listed in ()):(4) 22.5in x 22.5in (top/bottom)(two will be used for bracing)(2) 22.5 x 30.5 (two sides)(2) 24 x 30.5 (two sides to close in the others)

*edit* I'll take pictures as I go and then post them. Hopefully this will be atleast half-way interesting to a few people.

If you want exact tuning specs please ask and I'll post them


Modified by PoorManQ45 at 9:00 AM 2/13/2006

[PoorManQ45]

Here are some pictures of the dry assembly. Use the piece of wood that the box is sitting on as a reference. It's 4ft wide.

[Looneybomber]

I'm curious, what kind of a joint are you using on that enclosure? It looks like a butt-joint. Even though that's not gonig to be a sealed enclosure, having 1000w thrown at that Dayton will more than likely split some joints

[PoorManQ45]

I'm using butt joints with a 1x2 running th elength of every joint. The reason for this is to have something very solid to screw in to. It would be just fine without the 1x2s though.

The enclosure has two internal braces connecting three sides.

Looney: I'm only going to use the 250w Plate amp as it has a continuously variable phase knob. This will allow the sub to integrate into the rest of the system unnoticed

[PoorManQ45]

Here are all the specification pictures:

Maximum SPL FS = 19hzMaximum SPL FS = 13.5Impedance FS = 19hzImpedance FS = 13.5hzImpedance Phase FS = 19hzImpedance Phase FS = 13hzTransfer Function Phase FS = 19hzTransfer Function Phase FS = 13hzGroup Delay FS = 19hzGroup Delay FS = 13hz

[audtatious]

Not too shabby. If you used a table saw for those cuts, I'd replace it with a more accurate one

Just giving you some crap .... Anyway, is that particle board or MDF? That stuff tends to leak air through it (I've seen tests with industrial vacumes actually sucking enough air through those to pick up the table below two 4x8 sheets) so I suggest coating the inside with fiberglass resin for a good seal.

I assume you are going sealed?

[PoorManQ45]

The joints will be sealed, then a 1x2 corner braces sealed again.

Then I will be finished it with 1/4in oak that will be stained and/or sealed.

The edges will be quarter rounds.

Don't worry, it'll be sealed good enough

Thanks for the advice though. BTW, it's 3/4in MDF

[audtatious]

Good deal...

FWIW, while I use it, I tend to dislike MDF and HDF. Splits too easy, even with my brad-nailer. That's why I now prefer to use 1x1 solid-wood runners along every seam so I don't have to shoot into an edge...

[PoorManQ45]

Good deal...

FWIW, while I use it, I tend to dislike MDF and HDF. Splits too easy, even with my brad-nailer. That's why I now prefer to use 1x1 solid-wood runners along every seam so I don't have to shoot into an edge...

Hence why i'm using 1x2s in the corners

BTW, if you ever want to screw into the MDF joint you MUST predrill the hole or else it will split.

[audtatious]

Hence why i'm using 1x2s in the corners

You mention corners, I use them for all seams. Not just corners.

BTW, if you ever want to screw into the MDF joint you MUST predrill the hole or else it will split.

Now who's being

[PoorManQ45]

You mention corners, I use them for all seams. Not just corners.

Huh? Where is there a seam that isn't a corner in a box?

[audtatious]

Huh? Where is there a seam that isn't a corner in a box?

Corner = area where three surfaces meet.

[PoorManQ45]

Oh, oops.

Well then yes, I put a 1x2 at every joint.

[audtatious]

Oh, oops.

Well then yes, I put a 1x2 at every joint.

LOL...

OK, carry on then.

[phuphyter]

Update please

[PoorManQ45]

Mkay, all the sides are put together. The internal braces are in. I rough cut the hole for the driver and the ports.

I left the top panel off so I have easy access to the inside.

All that's left to do is buy the amplifier and the sub, stain the oak and then install everything.

[phuphyter]

What? You're not done yet? j/k

Funny, I thought you already bought everything but the box. Well, when you get everything put together, pics would be cool

[PoorManQ45]

Yeha, the amplifier costs $125, and the driver is $195.

I just had to spend $187 for a first time registration in florida.

[Looneybomber]

Yeha, the amplifier costs $125, and the driver is $195.

I just had to spend $187 for a first time registration in florida.

Excuses, excuses.

[PoorManQ45]

YEah, I know. It just sucks when I only make ~$180 a week. Imediately $40 is taken out of that for gas and food.

The rest goes in the bank. I'm almost ready to buy stuff

[PoorManQ45]

Subwoofer was purchased last week.

Arrived on Monday.

Now I have to cut the hole to fit the driver(previously rough cut).

Then I can stain the oak and put it on.

I am changing the design a little bit.

For feet/legs I am going to purchase Table legs. I'll cut a 90 degree angle into them and put one on each edge. The leg will extend all the way to the under side of the top.

For the top i'm going to make it into a coffee table like top.

[BlackHat]

I used wood glue along with screws in my boxes. The board will break in the middle before that wood glue gives if done right. Just a suggestion. You still should go over it with some silicone just to make sure it's air tight. Sometimes wood glue won't give a good seal (although it should if you see a bead along the entire joint, it's just hard to make it do that).

Box looks good so far. I look forward to seeing more pics!

[PoorManQ45]

I agree. I always use screws combined with 1x2s on th eedges and some sort of adhesive/sealent. I used polyurethane because that's what I had laying around.

I also agree ago going over the joints atleast twice to seal them. I actually have three/four seals. FIrst is the butt joints themselves have sealant. Then the 1x2 is sealed and screwed to both walls. Then when that dries I press another bead into th eedges.

Then finally, the oak is going to be sealed with polyurethane(no stain). That'll be glued on.

[Looneybomber]

*taps watch* Ok, so what's taking so long?

[PoorManQ45]

Money dude!

I have the sub, ports, and the box built, and the oak panels cut.

THe first layer of satin polyurethane is drying on the red oak paneling now.

THe amplifier will cost $150.

Hopefully I can order it soon, or I can have dad get it, but then he'll charge me $200 to retake ownership... LOL.

[PoorManQ45]

Pictures of panels on.

[Simmsled]

Neat!

[PoorManQ45]

Thanks simmsled.

ANy input?

[BlackHat]

Those are bulkheads inside? Or are there for some other reason?

[Simmsled]

Well, since you ask... Just make sure your ports are nice and tight, sealed (around the edges), and secure. The same goes for your sub. You'd be suprised how different the response is of a leaky ported enclosure. It appears that you are tuning the box to 19hz, so you will not really even need a subsonic filter to filter out whats below 19hz. Have you considererd lining the walls ((NOT THE BOX)) with fiberfill? Lining the walls and not the box is beneficial when you have the proper bracing like you do. Whatever you do tho, make sure not to fasten anything on the inside of the box with nails or staples. Glue/screws only. For the obvious reasons of them coming loose and being attracted to the magnet assembly. Naw man, looks good! Are you going to stain the enclosure?