I have a project that I need some help with. Way…..way back in college, I was at an outdoor party. The music that was being provided was from a home-built car stereo (cassette, not 8-track) equipped with 2 car speakers and an equalizer all built into a wooden box the size of a boom box. It was hooked up to a car battery. I thought this was ingenious. It ran all day. It has stuck in my mind all these years. Does anyone know of a how-to book or article?