In the setup I have now, I will have one 15" LA. I'm going pure SQ with my system. At the moment, I can't find any sound that causes distortion, even at full volume. I've tried pipe organs, pianos, different reed instruments, nothing even phases it, although the higher keys on the piano sound shrill, so I need to adjust the tweeters. My current sub is my systems big weakness, which is why I'm getting the LA. I hope to have every frequency covered. You can cram as many 15's into the car as you want. As long as you adjust it properly, you can have very good sound. You just need to match all the parts up properly. You can't have a high class amplifier running factory speakers, it won't sound right. You also don't want the factory amp running a $500 set of components, they require more power to optimize thier performance. So basically my answer is the same as Dave's. Except that in my version, you should poop on your stereo...
