This is a cheap way to boost the sound from an unpowered set of external speakers.
This particular speaker I bought at Dollar Tree and all it consists of is two speakers and an audio jack. The sound is not very loud at all.
Step 1: The Housing.
First thing I did was take it apart. I then cut two strips of posterboard two inches wide and five inches long, and curled a strip around the speaker, making a tube 2 inches long. I marked where they overlapped, then took out the speaker and glued both strips into two separate tubes. Two tubes for two speakers. I then cut a short strip 1 inch wide and glued this into one end of the tubes to make a stop for the speaker, then set both tubes aside to dry.
After they dried I slid the speakers into the tubes and pushed them forward until they hit the stop. I glued a few strips of posterboard behind the speaker to hold it in place, glued the two tubes together, then set it aside to dry.
After it was dry, I cut a tiny notch into the tubes to run the wiring for the speakers through, then ran a line of white glue around the back end of the housing and set it on a piece of posterboard and set it aside to dry. Afterwards I trimmed the backing of the tubes.
The speakers now have a resonance area behind them to boost the sound, and the tubes in front focus the sound, so NOW the speakers sound is boosted roughly five to ten times of what it had been before.
Step 2: The Enclosure.
The enclosure is a simple box made from metal-foil posterboard. The cutouts allow the sound to exit the box. What I am going to do glue a piece of thin colored tissue paper or cloth inside each of the sides, then glue the housing inside the box, and make an insert to cover up the housing.
The insert will be recessed inside the box, and into it I will cut a hole just large enough to thread the audio jack through.
After that, it will become an external speaker for my MP4 player. I will add something to this box so I can clip my player onto it.