yes 800 is split between them so each will be getting 400 watts. I personally don't like groundounders and think thats how you get your system stolen and damage yoru hearing imo. Anyways as i see it you have two choices different box, ported or bandpass but you need it tuned kinda high and a sub sonic. Probably won't sound good but will be loud or the other option is to go with a different speaker maybe something that is a bit more expensive. You might want to ask around on www.soundillusions.net or www.caraudioforum.com they will probably be able to help you out more than i can.