i was checking the B & W 803 D3 and the specs says to go down to 16 Hz. How can that be? these speakers have two 7" woofers. unless I'm completely ignorant, but I think that the laws of physics don"t allow for two 7" woofers to go that low. Am I completely, incorrect here? \nDo they make these kind of claims because few people would be able to hear below 20 Hz?