Introduction: Speakers Made From Recycled and Reused Materials
"Music is the universal language of mankind."
--Henry Wadsworth Longfellow
Here's a good way to make a great-sounding set of speakers using recycled and reused materials. And the best part--they didn't cost me a dime. Everything in this project was recycled, reclaimed from old equipment, or came out of my spare parts bin.
The project started with a pair of basic 8 ohm, 5W speakers I pulled out of an old boom box. Unfortunately, I couldn't find any other specifications for them, so I decided to use the following method to make a pair of custom enclosures for them.
The heart of the system is a 3W PAM8403 stereo amplifier I had in my spare parts bin. The enclosures are made from cardboard and vinyl shelf liner. An old hand towel is used for acoustic baffling, and some small pieces of scrap plastic reinforce the cardboard at key points.
Plastic shoe box
8 ohm, 5W speakers
50K ohm dual potentiometer
3.5 mm audio plug and cable (mine came from an old pair of earbuds)
Vinyl shelf liner
Self-adhesive rubber pad
270 ohm resistor
PAM8403 stereo amplifier board
LM7805 5V regulator
9-12V power supply
scissors and assorted cutting tools
Step 1: The Planning Phase
First, decide what you want your speakers to look like. I decided to go with a basic design for mine. I drew cutting guides on paper, and used them to mark the cardboard. Be sure to make your enclosures longer than you need--we will trim them down to size later.
Next, gather your materials. The cardboard should be thin and stiff; cereal boxes work well. By gluing two or three layers of thin cardboard together, it will be stronger than a single layer of thicker corrugated cardboard. The cardboard goes fast; it takes a surprising amount to make a small box. Be sure to start saving ahead of time!
Vinyl shelf liner will be used to cover the enclosures. This is readily available in any color and pattern. I used a roll of plain black shelf liner left over from a previous project, but a quick search online or at the home section of your local store will provide all kinds of ideas and options for any style.
A plastic shoe box can be used for some small pieces of plastic for reinforcing the cardboard. These boxes are usually made of polypropylene. It is difficult to glue, but easy to cut and drill, and is very strong.
An old hand towel makes great acoustic baffling inside the speaker enclosures. Mine was a casualty of an unfortunate incident in the wash machine.
Finally, the electronics. Since my speakers are only 5W, I used a 3W amplifier board. With a 5V regulator, the system can run off of any 9-12V power supply. (Actually, a 7805 regulator can run on 7.5-18V.) A common LED and resistor make an on/off indicator, and a simple switch turns it all on and off.
Step 2: Build the Enclosures
Cut out your cutting guides, and use them to cut out the cardboard. By gluing two or three layers together, it will be strong enough to serve as an excellent speaker enclosure.
The front of the left speaker, where the controls are, should be fitted with a strip of plastic to provide extra reinforcement.
Once the enclosures are built, cover them with the shelf liner of your choice.
Step 3: Test the Electronics
Assemble all of your electronics in a temporary setup. Test it, and make sure it is all working correctly. Be sure to write it all down for the next step.
Step 4: Mount the Electronics
Once everything is working, solder it all together, and test it again. Make sure everything is working correctly before you start mounting any of it--fixing it now will be much easier than later.
I used small rivets and the mounting rings to mount my speakers to the front of the enclosures. The right speaker wire I wrapped around a small ferrite bead to help prevent interference. After mounting the speakers, I installed the speaker grills.
Finally, I mounted the LED, switch, headphone jack, and potentiameter.
Step 5: Final Testing and Assembly
I would like to pause a moment and give credit to Instructables member mxx and his instructable "Determining Enclosure Size for Small Speakers" for the following idea.
Because exact specifications for these speakers are unavailable, it is impossible to calculate the best size for the enclosure. However, a good approximation can be made by adjusting the back panel until the desired sound is found.
Connect the speakers to an audio source and turn them on. Place the back panel in the back of the enclosure, and see how it sounds in various positions. A good way to do this is to start at the extremes--place it as far in as it will go, listen a while, then try positioning it at far out as it will go and see how it sounds. Keep listening and adjusting it. When you find the best position, mark it with a pencil. Turn off and disconnect the speakers, and remove the back panel. Cut the enclosures back to the line you marked.
Before re-inserting the back panels, line the insides with the old towel. Cut pieces to fit, and glue them in place, as shown in the pictures.
Place zip ties on the wires to prevent them from being pulled and damaged.
Re-insert the back panels and glue them in place.
Finally, put some rubber feet on the bottoms of each speaker enclosure. I cut mine out of an adhesive rubber sheet.
Step 6: Finished!
And there you have a set of personalized speakers no one would guess came from recycled and reused materials. Connect them to any audio source, select your favorite music, and enjoy!
This is my first Instructable. If you enjoyed it, please vote for it in the "Recycled Speed Challenge".
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