Weird and unusual shaped subs

m4rky_m4rk · 02-10-2009, 8:33 PM

The Death Star thread got me wondering what other unusual shaped subs are out there.

I found several rocks, a rubrics cube, nitrous oxide tanks.

Rock Sub

Rubik's Cube Sub

Nitrous-Oxide Sub

Ball

Sputnik Its 3000 dollars

More EBTB weird speakers and subs Everthing But the Box Unveils Sputnik Subwoofer | Elite Choice

I actually have two JBL Rocket shaped subs and alien speakers

Rocket sub and alien speakers

I guess they do not always have to look like a wooden box. Food for thought for the DIY'ers who have to factor in a WAF.

For speakers the choice is more varied. Here's some plant pots:

Plant Pots

**IronGiant** · 02-10-2009, 8:46 PM

you've missed the thread on here where someone built one from a kevlar missile nose cone

I believe he built his, rather than borrowing photos off the internet

m4rky_m4rk · 02-10-2009, 8:50 PM

I do have a couple rocket subs.. see above. I added a link. I never mentioned it before because I never think of it as a real sub. Actually it looks cool (IMHO) and sounds pretty good for what it is. Lots have wondered where the bass comes from.

Russell.Williams · 02-10-2009, 11:31 PM

Quote:

Originally Posted by IronGiant

you've missed the thread on here where someone built one from a kevlar missile nose cone

That would be this one.

I don't suppose it bears mentioning that anything other than a box is an inefficient maximization of occupied volume? It doesn't? I'll get me coat.....

Russel

**IronGiant** · 03-10-2009, 12:13 AM

Pragmatic as always Russel

Dav

Nimby · 03-10-2009, 6:47 AM

Quote:

Originally Posted by Russell.Williams

I don't suppose it bears mentioning that anything other than a box is an inefficient maximization of occupied volume? It doesn't? I'll get me coat.....

Russel

But a box is an inefficient maximization of panel resonances since so much stiffening must be applied.

A spherical enclosure is best for resisting enclosure wall flexure followed by the cylinder. The former is quite hard to find ready-made in larger sizes. (for a subwoofer) While cylinders are commonplace objects found in many different materials.

I used to tout the idea of spherical GRP fishing floats for enclosures but for some strange reason people objected to having bright orange balls. I can't think why. The advantages are so obvious and worked well in practice at very low cost. I wouldn't be surprised if B&W (and others) nicked my idea after I posted images of mine online.

I often think there is room for considerable imagination in the design of external reflex ports. It seems so obvious to drag them out into the light and show them off in brushed aluminium or stainless steel. Rather than folding them tightly inside what is already a very cramped space.

m4rky_m4rk · 03-10-2009, 7:45 AM

I think you are right. A box is a bit boring and often tries to hide and merge amongst the furniture. As long as the sound isn't adversely affected subs could be an opportunity for some design creativity. DIY'ers could create something very stylish,,, or maybe not. Most seem to choose a surface finish of either veneer or painted. There must lots more materials these days to choose from. I did wonder if a sub could be tiled for example... with some designer tiles of course. The Death Star Sub got a lot of attention on the internet on looks alone.

Everything But The Box seem to think this way.

Here some crazy looking horn speakers

AngelEyes · 03-10-2009, 9:15 AM

If my DIY skills are up to it, I really want to try something that will sit well with my teardrop shaped XTZ 99.36 cabinets.

This sort of project will be very labour intensive which is probably why boxes are so popular.

Sunday I will be hopefully getting some tips from a joiner, so if I end up building a box you will know it didn't go well

Adam

m4rky_m4rk · 03-10-2009, 10:16 AM

I guess boxes are used because they are, as you say, cheap and easy to make.

Boxes are not the ideal shape for speakers and subs, correct?

Couldn't any shape be made by using wire mesh frame and fibre glass on top? TVR used to make some very nice curvy shapes and its very strong too when made of several layers. There's plenty of fancy paint jobs that could be done for the final finish... I guess it will all add up in cost though.

**IronGiant** · 03-10-2009, 4:24 PM

Ask Namuk, I'm sure he can give you lots of tips

Nimby · 03-10-2009, 4:30 PM

There are spherical GRP fishing floats available up to (at least) a couple of feet in diameter if you can find a fishing boat port.
They are thick and tough enough to take self-tapping screws once you saw out a hole for the driver with an electric jig saw.
Primed and painted nobody would ever know it was bright orange.

Easiest enclosure you will ever make.

m4rky_m4rk · 03-10-2009, 4:57 PM

If you look around there are many spherical enclosures... I found some Googling septic tank and the like

This one is 250L and stainless steel.

Product:*Tank spherical stainless

With a bit of imagination....

The larger ones could be useful as an IB

paulst10 · 03-10-2009, 5:54 PM

All you need is a balloon, some paper mache and something sharp to pop the balloon when finished

deansocial · 03-10-2009, 6:57 PM

ACRYLIC* SPHERES

Moonfly · 03-10-2009, 7:05 PM

Quote:

Originally Posted by deansocial

ACRYLIC* SPHERES

Top find, I can see The_Force getting a couple of these to build his own Death Stars using parts from his Fathoms

deansocial · 03-10-2009, 7:17 PM

i think metal spheres can be spun out of sheet metal. Just would have to find a company that does it

m4rky_m4rk · 04-10-2009, 1:58 PM

Found someone who built a large spherical sub. It looks funky:

Orb Audio speakers, but what about a sub? : reZenerate

m4rky_m4rk · 04-10-2009, 2:41 PM

Whilst exploring I came across some articles on subs with spiral horns built into the port tube.

Like this

What's the advantage? Is it combining the advantages of horn amplification and a port tube?

I can imagine that the spiral pitch could be varied so it flares out towards the opening.

If you get to the bottom of the article above you will see he adds tennis balls into the cabinet for bass dampening, or maybe its also volume fine tuning?

**IronGiant** · 04-10-2009, 6:32 PM

There is a page on why use a spiral, but I'm left none the wiser

I can only think it is supposed to mimic a longer port, but in a compact space.

Dave

*banners* · 04-10-2009, 6:41 PM

The cross sectional area is tapered, to the diy'er this is difficult to achieve with tubes. It may also help stop the port/tube resonating itself.
TBH it looks far more complicated than it needs to be IMO!

m4rky_m4rk · 04-10-2009, 7:13 PM

Quote:

Originally Posted by IronGiant

There is a page on why use a spiral, but I'm left none the wiser

I can only think it is supposed to mimic a longer port, but in a compact space.

Dave

The pitch of the spirals gets wider towards the opening. I am intrigued. It is like a horn within a tube somehow. Maybe it amplifies the same and help remove port resonance.

I did see other info elsewhere on methods for making the spiral. It didn't seem to hard. It was made of many identical cut outs stacked on top of each other. A bit like how you might build a spiral stair case. Why go to the effort, what is the advantage?

I did a little calculation of box vs sphere foot print. The box wins by factor 2 for the same volume. In other words for a cube of diameter d you would need a sphere of diameter 2d for same volume. Spherical subs occupy twice as much floor space as cube sub.

deansocial · 04-10-2009, 8:28 PM

surely how it sounds is more important than foot print

Nimby · 04-10-2009, 8:39 PM

Quote:

Originally Posted by m4rky_m4rk

The pitch of the spirals gets wider towards the opening. I am intrigued. It is like a horn within a tube somehow. Maybe it amplifies the same and help remove port resonance.

I did see other info elsewhere on methods for making the spiral. It didn't seem to hard. It was made of many identical cut outs stacked on top of each other. A bit like how you might build a spiral stair case. Why go to the effort, what is the advantage?

I did a little calculation of box vs sphere foot print. The box wins by factor 2 for the same volume. In other words for a cube of diameter d you would need a sphere of diameter 2d for same volume. Spherical subs occupy twice as much floor space as cube sub.

Volume of a sphere: 4/3 Pi r^3

I haven't read anything on the subject but if the pitch of the spiral or its area changes then someone may have hoped that the deign would avoid strong pipe resonances. I don't think this can be true because the overall length remains finite and the pipe fundamental and harmonics may well fall within the powerband. Many musical instruments use slow tapers to achieve certain objectives. The only obvious advantage to a spiral is that the over-long port is made more compact in length at the expense of greater diameter. Note that the web page was last amended in 2005. This suggests abandonment of the project.

Nimby · 04-10-2009, 8:49 PM

Quote:

Originally Posted by deansocial

surely how it sounds is more important than foot print

Indeed. The sphere has one distinct inter-boundary dimension which is easily controlled with a loose acoustic packing. The diameter for the same volume is larger than any single dimension of a cube or similar box. It does not suffer from panel resonances since the sphere stretches but little around the circumference under cyclic pressure.

I turned a pair of Linn Kans into 10" GRP spheres. (more strictly speaking torus enclosures since they had a moulded through pipe for a rope) These sounded far better than the original kiddy's shoe boxes.

m4rky_m4rk · 05-10-2009, 11:53 AM

What happened to the Tactile Death Star Sub woofer thread.

Can't find it any more. Moved, deleted?

paulst10 · 05-10-2009, 11:56 AM

Quote:

Originally Posted by m4rky_m4rk

What happened to the Tactile Death Star Sub woofer thread.

Can't find it any more. Moved, deleted?

Must have blown up again

**IronGiant** · 05-10-2009, 12:22 PM

Quote:

Originally Posted by paulst10

Must have blown up again

It was deleted at the request of the OP as he didn't intend people to take it at face value and think he was actually building it.

I can clean it up and reinstate just as a thread about the original 2005 build.

Dave

m4rky_m4rk · 05-10-2009, 12:25 PM

Not sure why it blew up, it was harmless

Any way, it left a debris trail all over the internet so pictures are not hard to find. IronGiant had done a could job of putting all the pics in one place so its a pity the latest thread has now crashed and burned. Google did pull it up briefly but the link was broken.

The v.old and not as good thread is still on AVF .... the sub sold for 310 back in 2005.

Talking off unusual subs. I found another one

Elemental Designs Dodecasub

Edited to add:

The Death Star has retruned

**IronGiant** · 05-10-2009, 12:37 PM

No problem, I'll give it a dose of thiopental, dust it off and re-instate it

micb3rd · 06-10-2009, 8:29 PM

The Dodeca is an interesting subwoofer.

It a dipole affair as it has 10 woofers, 5 wired in phase (the upward facing drivers) and 5 wires out of phase (the down ward facing drivers) in a sort of push pull affair.

So this mean it is directional, i.e when aimed on axis and within a certain distance you get good bass, as you go go off axis (say by 90 degrees) the the bass is canceled away.

Bass also reduces as you get further away much more than a normal suibwoofer.

EDIT: I found the video back in 2007 that explaned this.

http://www.youtube.com/watch?v=vqWS4...e=channel_page