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Sonotube Subwoofer

David_NC

David_NC

Super Member
I've been wanting to build a relatively big subwoofer for a while now, and a friend has offered to assist by cutting the end pieces with a CNC machine, which will be fun (since I get to participate in that). Any suggestions as to what I'm considering will be appreciated! The end caps will be doubled 3/4" MDF, with one fitting inside the tube and the other slightly wider having a 1/4" deep 'ring' CNC'ed into it to allow the tube end to be recessed. I'm planning on a 4" port on the top.

I'd like to keep the diameter under 24", since 24"x24" will be the size of the MDF squares we'll be using. I'd like this to have decent very low frequency output, so being a bit tall won't matter so much (48" seems to be about right for the larger driver).
Here are the drivers I'm considering, mainly the 15" (again, suggestions for others that will give me the low frequency output I'm going for will be great):

Adire Audio Tempest 15": www.adireaudio.com/product/tempest/
Fs: 18.9Hz
VC: dual 4 Ohm
Vas: 292.07L
Xmax: 14mm (one way)​

Adire Audio Shiva 12": www.adireaudio.com/product/shiva/
Fs: 21.4Hz
VC: dual 4 Ohm
Vas: 157.26L
Xmax: 16mm (one way)​

I'd love to hear from those who've built a Sonotube subwoofer and any ideas they have on this. Thanks!
 
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Built 18 Sonotube subs so far. The subs that have the best transient /sq and play the lowest with the most punch are from Stereo Integrity . The last 2 were for a friend of mine and I used 26" diameter tubes, 5ft tall, down firing positioned about 5 inches above the floor on 1/2" all thread rods. Used a 6 inch Aeroport in the top tuned to 16hz. Covered the tube in black indoor/outdoor carpet, sprayed the top and bottom plates with satin black paint. He used the HST 15 models from Stereo Integrity but should have used the 18" models as big as the tubes were. The drivers were 90 lbs each and have 4 inches of travel. Takes up very little space standing up near a wall.
 
Measure the ID of the particular tube you are using. They are often manufactured in a variety of sizes, so multiple tubes of the same nominal size can be shipped nested inside each other to save space.

Some flavors of tubing have a slippery waterproof coating on the inside that resists glue adhesion. This very thin layer can be carefully peeled of by hand- once you get it separated at an edge, you can peel it out of the entire tube in seconds.
 
My DIY Sonotube subwoofer is about 7 cubic feet.
44" Long x 20" ID heavy-duty Sonotube (22" OD)
Each baffle is 1.5" MDF made from doubled 3/4" MDF (the inner/smaller ID is beveled for a very tight compression fit)
Top-mounted 15" Eminence Omega Pro
Bottom port is approx. 4" ID x 11" (possibly 13", from memory)
Stands on three legs approx. 5" tall, with long bolt running through fat dowel and both layers of MDF into T-nut. Cap head of each bolt rests on tiled concrete basement floor.
Woofer is similarly bolted through both layers of baffle into T-nuts and securely torqued (absolutely required to eliminate rattle/buzz at high SPL)
Empty SonoTube is approx. 80 pounds.
Complete assembly is approx. 140 pounds
Fed by a miniDSP crossover and parametric eq with 24dB slope at 50Hz into a bridged-mono amp (approx. 300 watts RMS)

I'm currently having difficulty with getting photos (and music) from my NAS server.
 
I pulled this unmarked paperboard tube from an old warehouse during a relocation; it is indeed probably another brand.
It may have been an industrial roll for storing material, as there is no good way to peel this behemoth off of a column of cured concrete.
The 1" thick sidewall is incredibly 'dead'.
 
Wow, 1" huh? No wonder it weighs so much. I've often wondered how it would work out by using two concentric Sonotubes with concrete poured in between. Problem would be getting all the air out (plus the weight :) ).
 
DeFriend said:
My DIY Sonotube subwoofer is about 7 cubic feet.
44" Long x 20" ID heavy-duty Sonotube (22" OD)
Each baffle is 1.5" MDF made from doubled 3/4" MDF (the inner/smaller ID is beveled for a very tight compression fit)
Top-mounted 15" Eminence Omega Pro
Bottom port is approx. 4" ID x 11" (possibly 13", from memory)
Stands on three legs approx. 5" tall, with long bolt running through fat dowel and both layers of MDF into T-nut. Cap head of each bolt rests on tiled concrete basement floor.
Woofer is similarly bolted through both layers of baffle into T-nuts and securely torqued (absolutely required to eliminate rattle/buzz at high SPL)
Empty SonoTube is approx. 80 pounds.
Complete assembly is approx. 140 pounds
Fed by a miniDSP crossover and parametric eq with 24dB slope at 50Hz into a bridged-mono amp (approx. 300 watts RMS)

I'm currently having difficulty with getting photos (and music) from my NAS server.
Click to expand...

Standard Sonotube is 1/4" and works fine, from what I've read, fortunately! I'd rather not have 80lbs in an empty cardboard tube! ;) If it was free, I'd likely use it due to its density. Otherwise, that sounds similar to the size I'm planning, though I'll put the woofer on the bottom for stability. The doubled 3/4" MDF is what I had planned, too. I'm considering trying the MiniDSP, too. How do you like it? Do you use it for low-pass only, or are you feeding your mains with it as well. I was curious as to any degradation from the AD > DA conversions, but otherwise, it looks like a great option... especially with the calibration mic. Do you know how low and loud it plays? It'd be great to see some pics of it, if you get a chance.
 
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