So i have built said enclosures form thick cardboard like materials about 1/2" wall thickness. These performed well but I can't get that material anymore. So I would like to know if anyone has ideas on this. I have tried sonotube from hardware store and it just seems too thin walled. Maybe 1/16" wall thickness. Has anyone tried 2 different diameters of sonotube one inside the other and pour concrete between the two? Is concrete non porous enough? Anyway like the tube idea just need to knbow where I can get it with thick enough walls.
1/2” thick cardboard tube is an unusually thick example of the genre.
Due to the cylindrical shape, the material can be quite thin and work well.
One can also use a bucket, PVC pipe (pricey unless you score a scrap), or some of the wood cyclinders available. I have done 1 pr pipe speaker and have PVC pipe for 2 x stereo pairs of woofers (8 & 12” PVC).
dave
Due to the cylindrical shape, the material can be quite thin and work well.
One can also use a bucket, PVC pipe (pricey unless you score a scrap), or some of the wood cyclinders available. I have done 1 pr pipe speaker and have PVC pipe for 2 x stereo pairs of woofers (8 & 12” PVC).
dave
Second advice on pvc pipe but buy scraps which cost v little. Easy to cut and sand to make even. Extremely rigid and doesn't ring much. Good for subs and easy to make end caps for.
Thin works fine since you're going to preload it a little bit with the [4] threaded rods tying it altogether/mounting the driver and extending down to act as legs/spacers.
Recess the hardware up top and use tabs of industrial Velcro to attach a heavy/decorative top plate.
GM
Recess the hardware up top and use tabs of industrial Velcro to attach a heavy/decorative top plate.
GM
A thin-walled concree construction tube will work fine, and potential resonances in the pipe will be at a much higher frequency than the top of the bandwidth and will not be excited.
Do note that the company that makes Sonotube™ has gotten mad at the forum for people using their brandname generically. Please don’t,
dave
Do note that the company that makes Sonotube™ has gotten mad at the forum for people using their brandname generically. Please don’t,
dave
No, the high pressure eigenmodes are along its length where a pipe is strongest, hence the 'preloading' recommendation/requirement; its cross sectional eigenmodes are 'limp-wristed' weak in comparison.
GM
So not completely understanding the preload explanation. I have built numerous subs with tubes(thick Wall) with just glueing and screwing MDF circular caps that fit inside the tubes. Are you talking about something different?
I believe that GM was talking about ready rod from one end to the other end under tension to greatly stiffen the 2 panels that will have maximum liklihood of ringing.
dave
dave
Right, run the rods through the driver mounting holes, end caps with nut/flat/lock washers on each side. Some folks covered them with alum/whatever tubes to hide the ugly hardware.
No need for them inside the woofer tube, though some used plastic pipes as spacers for preloading rather than gamble on over tightening.
There use to be a complete buildup article w/pics online from guys that later became SVS, but couldn't find it and don't have the original link. Then again, I keep forgetting that there's now all sorts of audio related videos on youtube, so have at it 😉: concrete tube subwoofer - Google Search
GM
No need for them inside the woofer tube, though some used plastic pipes as spacers for preloading rather than gamble on over tightening.
There use to be a complete buildup article w/pics online from guys that later became SVS, but couldn't find it and don't have the original link. Then again, I keep forgetting that there's now all sorts of audio related videos on youtube, so have at it 😉: concrete tube subwoofer - Google Search
GM
What have you used Dave? I have a few (8 +each roughly)feet of 777cm2 and 366cm2(sonotubes) to give to my son to stick something in?(the 8 and 12”). qW preferred, but not written in stone.
Subwoofer. At or near Fs and above ~x3
Fs 26.5hz
Re3.2
Le4.2
Vas58liters
Qes.53
Qms6.7
Qts.48
Xmax15.5mm
Sd570cm2
600watts
And/Or
38hz
3.8
4.2
22liters
.34
5.15
.31
15mm
506.7cm2
1000watts
have 2 of each
Fs 26.5hz
Re3.2
Le4.2
Vas58liters
Qes.53
Qms6.7
Qts.48
Xmax15.5mm
Sd570cm2
600watts
And/Or
38hz
3.8
4.2
22liters
.34
5.15
.31
15mm
506.7cm2
1000watts
have 2 of each
I used a piece of 6” PVC for the 1st pipe build. A crude TL.
the toobs Mk 1
The next 2 are not finished. A shortish section (2x) of 12” which will have 4 12” Foster woofers push-pull push-push. That wil use up 8 woofers.
Abd a tall 8” PVC pipe with 6” Eastech (out of Monsoon mutimedia speakers) in an ML-TL.
dave
I’ve cast a concrete speaker between two rolled up sheets of corrugated iron. It’s inert as only concrete can be. It’s also heavy @90 kg despite the small size. It ended up in the front garden with a flower in it... not to say it wasn’t fun making it. But moving the damn thing when rearranging furniture wasn’t.
I’ve now got three 950x550mm cardboard tubes with nearly 25mm wall thickness waiting for some 18” subs. The cardboard tubes weigh about 20kg each, very manageable. Compared to concrete anyway. These tubes started their life as cores around which some tons of steel was wrapped. Find a local steel shop and ask them if they’ve got any.
Tried to tack on some pics. Also note I used two sets of threaded rods in the concrete sub to hold it all together, as per the pre tensioned principle mentioned further up in the thread. That works really well.
Send pics of your build I’m intrigued.
I’ve now got three 950x550mm cardboard tubes with nearly 25mm wall thickness waiting for some 18” subs. The cardboard tubes weigh about 20kg each, very manageable. Compared to concrete anyway. These tubes started their life as cores around which some tons of steel was wrapped. Find a local steel shop and ask them if they’ve got any.
Tried to tack on some pics. Also note I used two sets of threaded rods in the concrete sub to hold it all together, as per the pre tensioned principle mentioned further up in the thread. That works really well.
Send pics of your build I’m intrigued.
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