Ok here are some questions: How does a mixer that is not powered work? Do I need to have a powered mixer in order to use as a PA system? For recording, my friend has the Tascam US-122. I want something like that except more channels for microphones and stuff. I need something thats $400 and below, any suggestions?
You will need a power amp before it can be used as a PA. The mixer basically takes the very weak signal from your bass/mic/whatever, and boosts it from under 1 volt, to a signal which is somewhere between 1 and 2 volts. At that level, it's strong enough to feed it to a recorder, or to a power amp. A power amps job is to convert that 1-2 volt signal into a much, much stronger signal and feed it to loudspeakers. A powered mixer is just a normal mixer with a power amp built in.