Ghettoghetto
Antti writes –

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.

Homemade boom box – [via] Link.