Competition sub are just plain old subs. Its kinda like "Tommy Boy"-I could take a crap in a box and call it gaurenteed, but it would be a garenteed piece of...well you know. So to answer your question, any sub will do, comp or not. You just have to look at the RMS. The higher RMS, usually, the beter. I mean if you want to compete, than you will have to do some custom work. but a good sounding sub is JL, Alpine, or even Rockford Fosgate.