Bass Ball Open Source Speaker

Joe Limon

Novice Member
Well I am going public on a little project of mine. It is an open source project so please join me or feel free to share it with anyone who you think would be interested in it.

A little information. This is a spherical speaker enclosure. The shape allows the sound energy to project ahead/around the speaker with a nice smooth diffraction loss curve.

Further, it is a ported speaker to help boost low frequency tones that small 3" speakers typically have a hard time reproducing.

To minimize resonance in the enclosure/port tubes I have smoothed all the pathways to prevent edges and surfaces for sound to reflect off. Eliminating these resonance effects again allows the speaker to accurately reproduce sounds without accidentally exaggerating or muting specific notes/tones.

To aid in port tuning, the speaker has a decreasing radius spiral that acts very much like the cochlea in your ear. High frequency sounds have a very difficult time bending around corners, so the spiral acts as a filter to remove these tones from exiting the port.

Finally, since little speakers need all the help they can get. All of the port pathways have an increasing radius spiral that doubles as a horn to amplify the remaining bass tones.

All of this in a tiny 7" diameter ball!

As I mentioned this project is open source.

If you want access to the file I used to print the speaker below, it is free and can be found in the link below.

Bass Ball by Joe_Limon

If you want access to a revised file which relocates the tubes a little farther apart to reduce the chance of the port tubes being connected as well as an added notch for running internal wiring. You can find this file in the link below for $20 USD. All you need then is a printer or acess to one and you can then print as many as you like.

Speaker bass 3D - TurboSquid 1170521

Finally, if you have no idea what to do with an stl file but would still like to order the enclosure(s) shipped to your door. I have a shapeways link. They don't do hollow/infill shapes so the build will be very solid/premium. However that comes at the tradeoff of added cost.

https://www.shapeways.com/product/875ZUKL9E/bass-ball…

I eventually want to produce these speakers but I am in need of a little extra cash flow to help cover the costs of prototyping. Which is part of the reason why I opened this project up. The other reason is because I would like additional subjective input on their design.

If anyone has any opinions, feel free to ask. And please, share this with anyone you know who loves awesome sound.

 

Ugg10

Distinguished Member
Interesting design, similar externally to the orb audio and focal spheres but very different internally. Thought about doing similar, but much simpler, with fibreglass sandwich structure spheres.

And pointers as to the drivers to use, I expect they are full range, would kef q series work if you had an external crossover.

Any idea of cost of the printing, ball park?

Is this design scalable to 6" or 8" drivers?

Finally, any lab measurements for these to show frequency response so a view on tone can be inferred.

Sorry lots of questions.

Good look, interesting project.
 

Joe Limon

Novice Member
I am using a Dayton dsa90-8 driver, so yes, a full range driver.

The design can be scaled to larger drivers. I just lack a printer capable of printing that large. Perhaps if this product gets off the ground, then I can afford investing in more capable equipment.

I do not have any measurements, although I do have an audio installer/audiophile friend coming with a spl meter. For now though, I am currently waiting for some wood based filament to come in. My next purchase, when I can afford it is getting an impedance meter to test/tune out resonance effects. I do however have some graphs for the driver by itself.
DSA90-8_fr.pdf
DSA90-8_imp.pdf


My last print quit part way through due to an extended power outage so I ended up using it as a night light. See pictures below.

If you have access to a 3d printer, my first prints are about 500 grams of pla per speaker. Or about $20 USD of filament. Wood filament is a bit more expensive though, at just over $30/kg. I am increasing wall thickness and aiming for 750g enclosures next attempt. But if you order it from Shapeways, it is also an option... but seriously, it's cheaper to buy a 3d printer to print a single speaker.



 
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Ugg10

Distinguished Member
Thanks, I was thinking that if you did an 8" base unit + the 3-5" mid range and a 1" tweeter you could stack them up with an off board crossover.

Bit of inspiration -

 

Joe Limon

Novice Member
Yeah, that has been done before. But really, my goals for this project were to try and minimize the use of crossovers by attempting to extend the usable range of a full range driver.

While I am fully aware that a properly tuned crossover is pretty much impossible for the human ear to find fault in. The fact that you still have overlapping frequencies in which you have drivers having varying fidelity bugs me. Plus when it comes to sub woofers, the wavelengths are so long that positional effects are minimal so trying to create a fancy spherical sub will yield far less improvement in audio quality.

Thus my goal was a single driver bookshelf speaker that could be easily/cheaply created by anyone and integrated with whichever subwoofer a person has to create a stereo/surround setup that would typically cost much more.
 

Joe Limon

Novice Member
Built my first wood speaker. Sounds much better! The plastic one seems to hum at low frequencies, and vibrates/emits mid/high range frequencies. This is probably due to wall thickness being too thin. The thicker/denser walls in the wood speaker appear to have corrected this.
20170703_181948.mp4


 

Joe Limon

Novice Member
I got some measurements. First some disclaimers though. The following graph is not compensated, and does not come from a measurement mic. I plan on eventually buying a proper mic, but for now I am using what is already available to me. The mic I have available is a rode lavalier, and the following link shows its fr curve. Also, there was a fairly loud computer fan in the background of these recordings. The amp I used for these recordings is also pretty cheap, it is the 100 watt bridgeable power amp from monoprice.

http://cdn1.rode.com/lavalier_datasheet.pdf

The measurements were taken in a closed 12'x10' room, with the speaker in a corner approximately 20" away from each wall.

This first graph shows the raw data. To note, data the speaker gets pretty quiet below 60Hz and the mic is garbage at these levels.

Next, with smoothing.
 
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Joe Limon

Novice Member
Better measurements. Recalibrated mic settings to record at a louder volume and thus minimize background noise effects like the pc fans. Also, I used a fiio a5 to provide a simple eq bass boost. At loud volumes however I ran into clipping issues at low frequencies. So I recommend against this.

Also, I recorded a single speaker and then both speakers. As a stereo pair they seem to fair quite a bit better.


 

Ugg10

Distinguished Member
Link to the Orb Audio and Anthony Gallo sphere speaker test that has a spectrum for comparison. Though this may be useful to bench mark against. Looks like your bass tubes are certainly filling in a bit more low frequencies than the closed box orb which has a pretty sharp drop off below 200hz and have nothing at 45hz.

Orb Audio Mod1x, Mod2x, and SubONE Speakers Review

Here a review of the Anthony Gallo A'Diva sphere as well, these drop off at about 150hz with nothing at 30hz.

Anthony Gallo Acoustics A'Diva Ti Speaker System HT Labs Measures
 

Ugg10

Distinguished Member
No problem. Been looking for some lab tests for the eclipse td series but not come up with anything yet.

Hi-Fi speaker | ECLIPSE Home Audio Systems

This is also an interesting project. Not the same concept but interesting nonetheless. A snail, cheap version on the B&w nautilus? Some interesting test results plus the use of some damping foam.

Loudsnail | Crazy Audio

Finally another interesting one, concentric tubes to create something like a transmission line maybe?

HUMANO® by AMI Full-range patented speaker – Redefining Sound | AMI International, Inc.

Here's a Pinterest of interesting speaker designs.

Loudspeakers | Crazy Audio
 

Joe Limon

Novice Member
There appear to be several snail shell designs on thingiverse as well.
The concentric tube design has me scratching my head as to resonance patterns and the diffraction patterns.
 

DrejerDK

Novice Member
Did you remove the 3D files, you previously uploaded?
They're gone from Thingiverse, and the paid versions aswell. :)
 

Joe Limon

Novice Member
I did for now. Am attempting other methods to help afford this project.

Send me an email if you want the latest version for free. joelimon at gmail dot com
 
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