...I have a ton of those $.50 4" full range Parts Express drivers they blew out. I want to make some speakers, and am debating the use of 4 or 9 drivers (those can get me to a nice 8 ohm load), or some other configuration. First question: How much will total SPL output change between using 4 and 9 drivers? I want to do a stereo pair in a ported or sealed box (leaning towards a ported box). Second question: How come when you have more drivers in the same size box, the bass extension DROPS? With 4 drivers in a 1500 cu. in. box, WinISD says it will go WAY lower than with 9 drivers. Is this because there is more air moving in a smaller box, and it isn't as good for low bass? Are there ways around this? Thanks!