Amy Winehouse

sub sounds like its blown?

i hooked my sub up to a house sterio to just test and see if the sub was blown and i did i hooked up my 15 inch kicker solo baric l5 to a house radio and it sounds like complete a$$. idk if thats cause the woofers blown but i did a digital multimeter on the terminals on the subwoofer and the ohms are fine so that raised the question that maybe its not the sub but it sounds like shit because the sterio is underppowered by like 500 watts cause the rms of the sub is 750 and the output of the terminals on the radio i know are not anywhere over 200… what could this be?