Once upon a time, many radios and TVs only came with a single (mono) speaker. Then someone decided all audio hardware should have as many speakers as we have ears. That was until [Olivia] came along, and whipped up a dodecahedron speaker as an educational piece for workshops. Really, it shows us that twelve speakers should be the minimum standard going forward.
The speaker relies on a 3D-printed frame. The dodecahedron shell is assembled from 12 individual faces, each of which hosts a small individual speaker. Multichannel audio fans shouldn’t get too excited—all twelve speakers are wired to the same input in four groups of three, making this essentially an exceptionally complicated mono device. It might sound silly, but it’s actually a great way to deliver audio in many directions all at once. [Olivia] even went to the effort of running some sweep tests in anechoic and reverberation chambers to see how they performed, which is a fun bit of extra detail in the build log.
[Olivia] notes that these unique speakers are great as a beginner workshop build. They’re easy to modify in various ways to suit different ideas or levels of ability, and they can be made for less than $30 a pop. We’d love to see an advanced version that maybe packed in a lithium battery and a Bluetooth module to make them a standalone audio device. Video after the break.
im still a “speakers found on the side of a road” kind of guy. just make sure rodents dont live inside. ask me how my know, and why my cats are fat.
Built an amp out of a Class-D module, 24V PSU and a gutted toaster. Speakers are classy though.
https://hackaday.io/project/204101-stereo-toaster
heh all my ‘speakers on the side of the road’ acquisitions have corroded contacts that i know i can work around easily and successfully but i have insufficient motivation. because i already have the pinnacle of home audio in my livingroom — the 1999 cambridge sound works pc speaker with subwoofer system.
but i recently wanted to install a separate speaker in my greenhouse, and for whatever reason i didn’t wnt to fix up something from the free speaker pile. but i hate review-shopping for audio equipment, so i found this shortcut…i just shop using my credit card rewards points. i don’t know how they curate it but i appreciate that they don’t even properly describe the product, it’s shopping with absolutely none of the details. so i got this soundbar, and hung it in the greenhouse. btw, it’s a total trip to have a soundbar hanging 3ft directly above my head, it is really a lot like wearing headphones.
the punchline is, after a few months i’m convinced, the new soundbar sounds better than the old pc speakers
sigh
Pot plants love GWAR!
They will grow big and strong, but buds will look like Cuttlefish.
GWAR buds are the best.
Ditch the sound bar, sing to your plants they will grow love you, do not sing to your plants and they will turn on us
I had (and still have, in a box somewhere, I think) a Cambridge Soundworks PC Speaker with Subwoofer system from around that time. Mine is/was a classic-PC beige 4.1 setup – a small sub that sat on your desktop, connected to your PC, with connections for the four satellite cubes on the back. It has/had these little plastic tripod stands for the rear speakers that were about 1.5ft tall.
Not what I would call high-end audio, exactly, but they were as close as I would get to real surround for many years.
RE: soundbar above your head, I have a cheapish one wall-mounted above my bed, linked to a Google Home speaker, that exists solely to play white noise tracks when I sleep. I added a sub to it that sits under the bed, to give those thunderstorm tracks some bass, and it lets me sleep like a baby…
Basically, building your own version of : https://www.hbkworld.com/en/products/transducers/acoustic/sound-sources/loudspeaker/4292-l#!ref_bksv.com
Which has been around for decades.
Technically, that’s not a dodecahedron, but an icosidodecahedron…
More like a DIY version of the Design Acoustics D12.
olivia from the article here,
that’s not a dodec speaker, but yes speaker builds have been around! the goal for this build was to make CAD, 3D Printinf, soldering, prototyping etc ACCESSIBLE for all, while also making sure the whole build is affordable ($10/pop if you have equipment like soldering iron already). i’m a huge advocate for STEM outreach, and believe that learning happens at all ages! thanks for reading (:
I started a project to make an electrostatic speaker about 18″ diameter, using a truncated dodecahedron about a year ago. I may finish it one of these days. The speaker will consist of two parts- the speaker assembly and a box that contains the bias supply and audio transformer(s). The speaker will be supported above the box by a pipe that goes into the speaker through one of the triangular surfaces, and carries the wires for bias and audio.
So far I have printed a smaller test version of the dodecahedron and a gluing jig to verify that the printer can print the angles accurately. They came out perfect, so the next step will be to scale it up.
I did something similar 25 years ago…gave it up as a bad idea.
It once produced low volume sound, then let the arcs and smoke out.
What material are you using for membrane?
How are you planning on keeping the membrane centered?
Somewhere about 50 years ago I saw in a zine a ball shaped multi-speaker that was rotated and gimbaled in an effort to out do a Leslie speaker at diffusing the source and making it sound like it’s coming from everywhere. Sadly Mr Leslie did that in the beginning with speakers all around in his rotating setup. It didn’t sound right, he tired disconnecting speakers one at a time till he had just one left and it sounded great.
The most successful product never advertised, the Leslie speaker.
We know the golden ratio dimension of boxes for sound but every so often some try to put speakers in a cube or sphere and get resonances that some think is good (loud) and boomy sound sells. If all those speakers were set in a line array you’d have a very good sound source.
Great project!! The project posting is very well documented – and the research over at PSU acoustics is world class.
thank you peter!
PSU acoustics program is really something special 🥰
Might be better with some kind of “waveguides”. Radial planes extending out from the intersections.
I have found that even a tiny piece of paper propped up behind my tablet speakers dramatically increases the delivered audio. I haven’t measured it, but I would not be surprised if it was in the 10-20dB range.
When I was a kid, I tried to make a icosahedron electrostatic.
One face was small Klipsch horn, everything attached to that.
Didn’t kill myself…
I’m not sure approximating a point source is a good idea acoustically.
hello!
dodec speakers are often used as an omni source for room acoustic measurements – so this isn’t for your every day listening! to be fair, the measurement grade ones will have crossover filters & account for more things, but this was a build for educational purposes (:
thanks for reading!
Was it me, there wasn’t sound in the video until the speakers were built?
Can you have it do stereo with half the faces left chan and the other half right channel?
hi! the video is actually just my PPT from the conference exported as a video, hence no additional commentary/sounds. I wanted it to show the dodec in action + some measurements I did!
you could theoretically, but you’d need to apply crossover filters & it frankly defeats the purpose of a dodec (omni source). i have seen people make 12-channel dodecs to control each driver separately though!
EEE FIR filters for the right surface / angles and other EQ filters for the multiple drivers !
Very nice, and, IMHO from the Wall of Sound to the (kind of) Ball of Sound : – ]
Obviously, making it into a stereo (or anything other than mono) speaker won’t work, as there will be multiple destructive interference focal points, inside and outside. For the true stereo I’d probably make two of these.
thank you for your kind words! it was really fun & rewarding to host the workshop, esp after seeing all the smiling faces + feedback that they’ve used CAD skills I taught them for other research as well (whoooo translatable skills)!
Very nice build. Has the old school look of speakers from the 80s when there were unique cutting designs like the down firing Ohm F. When I saw the pic it made me think of the ball speaker voice of Colossus/Guardian in The Forbin Project which I am watching. (Hint… maybe a silver ball speaker next ? )
thank you!
i do have a set of white that i could spray paint… 👀
It looks like the design from the JVC speakers from 1970