Hello, I've been playing bass for three years and while I'm pretty advanced in the playing of the bass my knowledge in amps is limited at the moment. So I have a few questions. By the way I'm currently playing on a crate BX-100 There is a a plugin on my amp for another speaker though it is a solid state amp. What kind of speaker do I need? What cables to hook it up. Will any cabinet speaker go with this or do I need something special? What exactly is a head? I now it's the part that decides the sound and loudness but what does it need to work? If I had an ampeg amp head what would I need to plug it into and what kind of cables do I need. The whole concept of preamps, heads, cabs, and all that eludes me. Just wondering if I could get some help.