stereo too crazy

I just got a job at mickey shorr, which is an audio accessory (Ghetto bumps) shop in my area, and they let me have a bunch of equipment. Well, i built boxes and transformers for everything, and got it all set up and it runs great, except, the bass is too insane. these are 3 phonocar 18 inch subs running 2000 watt audiobahn amps behind them, one for each sub. these subs are rated for up to 5000 watts peak, but the bass is too heavy. it broke one of the older windows in the house with the bass and all the volume controls on low. what i need to do is mess with windows and get it to turn the low end sound down. even the wmp equalizer dosent help. you can hear it down the street. Is there a software that i can use to drop the bass considerably ( or raise it if i put this system in my car (the comp is a laptop). but still keep my mid and high ranges up, because they are low enough anyway that they dont hurt anything. I really dont want to get rid of a sub, not if i can help the situation. Thank You