Coconut Speaker

7,903

17

16

Introduction: Coconut Speaker

About: I'm Chandra Sekhar, and I live in India. I am interested in electronics, and building small one-off circuits around tiny chips (the electronic kind).

Loudspeaker gets mounted into an empty coconut shell. Second life for the shell, improved sound from the speaker.

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: Gather Materials

One speaker. 2" dia, which I was using to listen to the output of a few experimental audio amplifiers intended for alarm and warning sounds. Volume was more important than fidelity, so some sort of a resonant enclosure was indicated. It measured about 7.5 ohms with my HiOki digital meter.

One coconut shell. In two halves, with a clean break and no pieces missing. Large enough to accomodate the speaker inside.

One more half shell (optional) for the base, if you do not want your enclosure to roll off the desktop.

Step 2: Drill Out Eyes

I drilled out the half with the three 'eyes' for the sound. The result looked like a face, so I enlarged the mouth a little bit more.

Step 3: Fit Bracket for Electronics

The other half was drilled to accept a bolt and nut to hold a bracket made of tin sheet which might hold a circuit board inside.

Step 4: Fix the Fabric to Keep Insects Out

I glued in a piece of acoustically transparent fabric, and checked the fit of the speaker.

Step 5: Fix the Speaker

A mounting hole was cut in the back half of the shell, and it was fixed to the base with a nut and bolt.

I used a two component epoxy filler to seal the gaps around the speaker. Since the shell is not perfectly round, air can leak around the sides of the speaker and this will lead to a loss of volume. I used a plastic bag to isolate the speaker from the sticky compound so that the cone would not be contaminated.

The filler will have to be cut away if the speaker ever needs to be replaced. But then it might be easier to make a new enclosure, because the replacement speaker might not be of the exact size as the old one.

Step 6: Solder on Wires and Test

Since I was using a third half shell as base, I decided to put any electronics in the base where it will be more accessible. So the bracket was not used.

A piece of twin flex peeled from a computer ribbon cable was used to connect to the speaker. It is led into the bottom through holes drilled for the purpose.

A cell (1.5 V) applied to the wires resulted in the production of clicking sounds, significantly louder than when the speaker was used in the open.

The two halves making up the enclosure was cemented together with synthetic rubber adhesive after testing. This results in an airtight seal.

No sound absorbing materials are used back of the speaker since the intent is to have a resonating chamber there. The reproduction will be decidedly 'peaky' with some frequencies emphasised. This is acceptable since the device will be used for alarm beeps and announcements.

A hifi version could be made, but I think a large enough coconut might be mighty hard to find, as well as to break in a clean way as required for this enclosure.

It does look like a face, with a pronounced expression. You could have a trio with 'see no evil', 'hear no evil' and 'speak no evil'.

The first will have no eyes. The second will have no ears. The third will have no mouth, and will house the stereo amplifier.

Have Fun

Be the First to Share

    Recommendations

    • Backyard Contest

      Backyard Contest
    • Silly Hats Speed Challenge

      Silly Hats Speed Challenge
    • Arduino Contest 2020

      Arduino Contest 2020

    16 Discussions

    0
    erosser
    erosser

    11 years ago on Introduction

    Anyone seen the "Milky Joe" episode of The Mighty Boosh? Creeeeeeepy...

    0
    poparoo4
    poparoo4

    Reply 10 years ago on Introduction

    Yer i hav AAAAAAAAAAAAAAAAAAAGGGGGGGGGGGGGGHHHHHHHHHHHH *runs and hides in corner*

    0
    The nerdling
    The nerdling

    Reply 8 years ago on Introduction

    my favorite episode.
    "can this thig go any faster?!!!!!'
    "aw, i got a stich!"

    0
    StrangeRover
    StrangeRover

    12 years ago on Step 6

    Now you can play Jared- the butcher of song!

    0
    PetervG
    PetervG

    13 years ago on Introduction

    I have a hollowed coconut shell cut in 2. I use them to make the Monty Python horse sounds like in the Holy Grail. "You're not a real horse, you know. What? You're not a real horse. You're two coconut shell halves, and they banged you together to make the sound of horses' hooves. So?"

    0
    Mitten
    Mitten

    Reply 13 years ago on Introduction

    But coconuts are tropical! This is a temperate zone!

    0
    eriklares
    eriklares

    Reply 12 years ago on Introduction

    actually, i think it mightve been an albatross

    0
    Mitten
    Mitten

    Reply 13 years ago on Introduction

    God I just realized how much we're mutilaing these quotes. Also, nice job on the speakers, very original.

    0
    castcase1
    castcase1

    13 years ago on Introduction

    Nice shell, is it a speaker amp? Or, just a shell.
    It looks really awesome :)

    ===========================
    TubeHunter downloads YouTube/PornoTube/xTube/yuvutu/LubeYourTube videos to MPEG/iPOD/PSP
    http://www.neoretix.com