Need help building Sonotube Subwoofer

[ketchamftw]

Hey guys!

I have to complete a culmiating project in order to graudate, and I chose to build a sonotube subwoofer at the recomendation of my (not very helpful) teacher. I don't know much about speakers or building them, so I'm kind of in the dark. My budget is a strict $200-$250 pushing it.

What I need right now is a parts list.

I am planning on buying a Dayton DC380-8 15" Classic Woofer for the driver, but that is about as far as I have gotten so far. Also, I am planning on buying some 24" sonotube (don't know the length to be cut yet).

Any and all help would be greatly appreciated!

[jbell]

search will give you several links, it's been discussed before.

A PROVEN formula, given to me by Dr. HSU if you want, is this:

18" sonotube, 26" interior dimension, a pair of 4" diameter ports 24" long, with an HSU 1203 driver.

You can accomplish it easily with your budget, and is STILL one of the best sounding (quality) subs I've built. And for SPL... I use these for small church PA all the time.

To make it look great, buy some stretchy black fabric, and sew it to make a fabric 'cylinder' so it can be stretched over the tube. (spray paint tube black first, to hide any lettering)

I personally like to use doug fir 2x12, glue/join a pair of 22" long sections together to make a 22"x23" blank, and then 'turn' it down on the table saw, which requires ZERO talent.

Here's a pic that I've posted before. I've literally made dozen's of these, and they work extremely well.

Don't skimp on the thickness/strength of the caps. The HSU driver can make 2x12 flex !!!!

ping me if you need more details. Also, be aware that the concrete supply companies that carry sonotube, only sell 12' long sections, and you'll probably get $50-$70 dollars in an 18" tube. 24" tube is obviously more expensive. See if you can at a minimum get a buddy to build a 2nd one, as a single 12' long tube will build 4.

http://hsuresearch.com/products/asw-1203.html
BTW the plus minus 18mm xmax of the HSU driver TOASTS the 3mm of the dayton.... Subs are about displacement, and that dayton is lacking.

good luck

[MarkR]

FWIW you need to use the search or you won't find much help on any of the forums. But I'm bored so here are some links.

Here is a link to one sonosub

another one

another



Here is a calculator, I've never used it so download at your own risk...
link

This one I have used but it seems to be not working right now? Maybe it's dead for good???
Link

I would also look into if the driver you list is good for a down firing set up. With 4.35mm of xmax I doubt it. You should look for a different driver IMO. PE has a formula for it on their site under "other resources" of the DIY resource tab on the left.

If you are strapped for cash and don't want to dump allot on a driver you may want to look at
this one

It's a 12" er but it has 12.5mm of xmax. And is only $53.00 so it's a little cheaper than the 15". You should still figure out if it can handle being down firing.

Oh and you will need a plate amp like this one

You just hook up your "sub woofer" pre-out to the input and you are good to go. After you build the sub enclosure first of course.

BTW jbell made a solid suggestion with HSU driver it will take most of your budget though once you get the sono tube and amp though.

[GM]

Originally posted by MarkR

This one I have used but it seems to be not working right now? Maybe it's dead for good???
Link

'Jumping' into the Wayback Machine : http://web.archive.org/web/200712080...o/diy/sonosub/

GM

[jbell]

good sonosub options there mark, applause from me.

as always, when on a budget... go here.

http://home.comcast.net/~jhidley/

You can't beat a $50 subwoofer plate amp, and something tells me you might find a use for a foster 10" or the 15" jack has to sell.

If this is just for 'class credit' and you want to keep costs REALLY low... Here's a shopping list you can consider.

1. $30 gets you the foster 10" and you get 13mm of xmax.
2. $10 or less gets you a 4' long piece of home depot cardboard tube about 12" in diameter, it's not sonotube by a LONG stretch, but workable. (they have various diameters, find the largest you can)
3, $50 gets you a sub amp.
4. Some scrap lumber to make the ends, and about $4 in fabric and you are complete for under $100.

The added mass ring to the NHT 11-083-2 driver gives it a VERY low fs of 16hz, which means you can put it in a small sealed and work very well. Just buy some polyfill and lightly stuff the cabinet. Sealed cabinets are the MOST FORGIVING of all of the subwoofer types you can build. A 12" diameter tube 18" tall gives you a F3 of 33hz with a very shallow roll off, which would match up well with the rising room gain of an average listening room, and get you flat response WAY DOWN into home theater territory. You'll get 105db output at 100watts. It would be a great little sub on the cheap.. maybe just what you need for class. The sub amp will allow you to drive 2 subs from one amp, so if you want more output, buy another foster 10" driver, and build 2 cabinets... 2 cabinets in corners of your room would actually get you THX levels at listening position.

You'll find several who'll champion the idea that multiple small subs actually sounds better than one big 'uber sub' so, this fits in well with that way of thinking. Also, the foster is a shielded magnet, so it can go close to electronics, tv's, etc.. without a problem.

again, good luck.

[MarkR]

Originally posted by GM


'Jumping' into the Wayback Machine : http://web.archive.org/web/200712080...o/diy/sonosub/

GM

Good call GM forgot about the wayback machine.

Jbell,
Could you explain your method of using a table saw to "turn down" the caps?
I think I know what you mean but how do you make sure you get a nice circle? Do you have a jig?

[jbell]

For turning on the table saw... it's so clever, it took a redneck with no sense of safety (me) to think of it.


1. Clamp a board with a nail sticking up through it to the deck of your table saw.

2. drill a small hole in your wood you want to cut, and place over the nail, that is positioned a radius the size of circle you want to cut away from the blade.

3. with the blade completely lowered turn on table saw.

4. raise blade till it just barely contacts the wood, and allow the blade to spin the wood. (sometimes its best to actually start it spinning by hand)

5. raise the blade at a speed that just keeps the blank spinning at a controlled rate of speed.

6. Be careful when you are about all the way through, as the 'excess' will come apart from the round blank, and you don't want it spinning wildly when this happens.

Somewhere I have a pic of this, and I'll post it when I find it.

This makes it SUPER simple (and fast) to take 1.5" stock (2x12) and turn 2 different diameters, so half goes inside the tube, and half goes over the edge, to create a nice clean look.

The key to this, is to have enough faith to let the wood actually spin. Once spinning, your table saw is effectively a lathe.

[GM]

FWIW, this is a safer way: http://www.videojug.com/film/how-to-...-a-table-saw-2

GM

[jbell]

Thanks GM.. I've done that with my sled, and with 1.5" wood, well, lets say I decided that spinning was easier, especially on my 1.5" oak tops I've cut.

It also allows me to create a 'step' by moving the pivot point in, and only going up through half of the thickness, at the smaller radius.

Good thought for 3/4" softwood/mdf/etc. If you want to cut 2 layers of 3/4" at different radius, and then glue them together afterward, this would be a good way of doing it.

[ketchamftw]

Thanks a ton for all of the help, it really means a lot