watts make decibles....think of it that way add that to what ranger said Decibals...decibals are a measurement of sound, so the more decibals the louder. You don't necessarly need a lot of watts to produce more decibals. There are a lot of things that relate to producing higher measurements of sound; cabin space, enclosures, subs, and amps are just a few. also sensitivity doesnt really matter unless 2 manufactures do it exactly the same way yes i know 1 w at 1 m but way it is measured and figured some just use a computer program without actually testing the speaker. plus encloser for the speaker will change sensitivity greatly