im new in forum. so my stuff will be a little late but helpful.
years ago i bought a book from radioshack for about $6.
i dont have it with me now, but it taught me everything i know about car audio. enough to do my 1st system at the time of
2 amps, 1 x-over, 1 pair seps, 1 pair f/range, sub, h/u and all the wiring i needed for a awsome instal. so check them out.