[Charles]

"Lets see 4 6.5's are equal to two 12's."

In my opinion this is incorrect. And then there is the question of how much excursion you can get out of a 6.5. This is the size of a midrange. How much coupling (air movement) can one actually get from a 6.5 inch driver. I'm not doubting Mac but I just don't understand. Could someone explain? For example I don't think 15 one inch cone tweeters equal one 15 inch woofer. My thought is that 2 6.5's equal about 1 eight inch woofer so you actually have the equivalent of 2 8's at best plus the port output. How do you obtain 16 Hz from this? Reading from the website Mac says it's possible.