Portable Amplifier and Speaker Box
Situation - A demand for a portable and self powered audio solution. Two weeks time and
250 euros budget: realistic equation? Well luckily I had my brother sharing the cost of
this project and giving a helping hand on the construction work.
The main idea of making a portable loud speaker system like this is to use sensitive
speakers and high efficiency amplifier to keep the battery as small and light (and cheap)
as possible. It will have only RCA input where audio source gets connected.
Choosing the Drivers
Reflex enclosure is a natural choice for a high efficiency system. I had three speakers to
choose from. All were tested outdoors, a normal environment for a ghettoblaster. The idea was
to find out which of the speakers had the best bass extension. Pioneers on the left were just
horrible. (in the white box) They are designed to be used inside a car so their bass
response outdoors is really weak and starts cutting off above 100 hz. Logitech's were okay
but they are pretty power hungry so black Audio Pro's won this roundup. They are really
sensitive speakers and deliver lots of sound. On the right you can see the crossovers and the
drivers. My plan is to build new a case using the same volume and tuning frequency as the
original boxes. They played so well outdoors, no need for changes.