Bass Ball Open Source Speaker

  1. JoeLimon
    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.

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    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.

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    All of this in a tiny 7" diameter ball!

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    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.

    https://www.thingiverse.com/thing:2398268

    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.

    https://www.turbosquid.com/3d-models/speaker-bass-3d-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.

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  2. JoeLimon
  3. HiGHFLYiN9
    Very interesting looking enclosure! Too bad you have to sell a kidney to get Shapeways to make one for you :wink:
     
  4. JoeLimon
    Indeed! It is cheaper to buy all the parts/materials for a bunch of speakers and a 3d printer big enough to print them. Than it is to order a single enclosure though Shapeways.

    If you ever wanted to justify buying a 3d printer, here is your chance :wink: haha.
     
  5. JoeLimon
    Got some wood filament!

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  6. JoeLimon
  7. JoeLimon
    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.

    https://drive.google.com/open?id=0B33BNXNUBij4UzdUSXAyWTZyZGs

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  8. HiGHFLYiN9
    Very nice, looks cool! Have you tried using a spectrum analyzer to see if any tweaks need to be made?
     
  9. JoeLimon
    I haven't had any access to equipment to test them. That said, the second speaker just finished printing, and I will be attempting to visit a friend with a proper spl meter this weekend.

    That said, I was interested, and with a HUGE disclaimer to explain my very flawed setup, I did do a peak recording. The red curve represents peak spl while listening to music over about 1-2 minutes. This is using the mic in my Galaxy S7. From my understanding, cell phone mics suck at picking up high and low frequencies, so a frowny shape as depicted below should be expected. The important thing to note however is a fairly consistent response curve.

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  10. HiGHFLYiN9
    Cool thanks for sharing! :) If you are still having any trouble with resonances, a handful of AcoustaStuf might be what the doctor ordered.
     
    Last edited: Jul 6, 2017
  11. JoeLimon
    Whoot, first set done. Gonna get some measurements this weekend.

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  12. JoeLimon
    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. Also, the amp I am driving them on is pretty cheap, it is a 100 watt bridgable 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.
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    Next, with smoothing.
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    Last edited: Jul 10, 2017
  13. JoeLimon
    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.

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