not sure exactly, it depends on alot of things. my friend has 2 in a ported box with a kicker kx.1200 in a cts-v. it POUNDS louder than these 2 15" MAs i heard once. But yeah, they're very loud if you do it right.
diymobileaudio.com is the DIY car audio install forum for automotive quality and spl stereo bass. 12 volt audio installation wholesalers buy amps, subs, double din car audio head unit electronics and ipod blue tooth car alarms at discounted prices