Sorry, I've searched around, but most sub FAQs only seem to cover downward vs. side firing subs... I'm thinking of experimenting with a sonosub with the driver on top firing upwards. What characteristics, advantages, and limitations will this give me? On the bottom, I'm flexible with either sealed, or even multiple ports. My other question is, do the ports have to be aligned in any sort of symmetrical configuration pointing towards the driver? Oh, and other dumb questions: Do the sum of multiple ports equal one long port? ie, 2x(4"dia) 12" ports = 1x(4"dia) 24" port? And does port diameter matter as long as volume is the same (3" dia vs. 4" dia both having the same volume)?