Sorry , wasn't meaning anything by it. I know I heard that before. Also, the one I mentions. 15 x 3.14 = 47.1 10 x 3.14 x 2 = 62.8 and 8 x 3.14 x 4 = 100.48 . So technically four 8" subs should move more air than a 15" by 2.5 times.
It doesn't quite work that way. You're missing a dimension, the movement of the cone, which is probably the most important. Think about this: a tweeter has a .75" dome. So 20 tweeters should equal a 15" sub. But it doesn't; a tweeter has such a small amount of movement. It'd take a whole lot more than 20 to get them to produce a 15 Hz tone at any audible level.
