My simple recommendation for a bunch of Frat guys on a budget would be to grab as many Yorkville LS800p/LS801ps you can find for your budget. Don't go super low but will rattle everything off of the walls. They are a bit boomy but that works well with the music they will be playing (or can be tamed via EQ). Lastly, they are mostly idiot proof and bulletproof plus one of the loudest subs in the sub $1500 price range. One Yorkville can equal a pair of similarly priced subs, IMO. I promise you they will fit your needs perfectly.
Did that about a decade ago, college bar had passive sub down because of an amp failure. I loaned them 4 LS800p.for a DJ event. I think they vibrated about $300 worth of liquor and glass off a poorly designed back bar by the end of Sat night..... I did warn them it was more than they had last week....