Also, I never really understood the whole concept of cone diameter relating to wavelength and upper frequency response. I know that as sound waves get higher in frequency their periods become shorter, but how exactly does this relate to the diaphram's size? I would assume that diaphram weight is not so much of an issue, so why could a 15" woofer not perform up to 20khz? If I remember correctly the larger the diameter the speaker is, the larger the off axis drop in higher frequency spl there is. Does it have anything to do with how the horn loading of speakers works? Thanks!