Originally Posted by Ricci
Oh...they do seem to have quite a bit of sensitivity to them too. So far me likey.
actually they don't. it's an illusion. each 21" driver is ( surface wise ) essentially a pair of 15" drivers. since you get 3db gain PER WATT from running drivers in parallel a box with two 15" PA drivers would be significantly more efficient than the 21" you got.
of course it would also have only 1/2 the xmax. so overall you made a good choice, i am just pointing out where that efficiency really is coming from.
in an optimal design xmax will be related to VC diameter by some number. this is more or less the case for prosound woofers of the same motor type ( internal vs external magnet vs differential drive are different ).
but also cone size will be related to VC diameter in an optimal design. so really there is no other good way to get nice xmax than this B&C driver.
the drivers you were into initially ( XXX ) were trying to get xmax for free - which doesn't work. then you upgraded your thinking and got LMS which recognizes that xmax has to be built on something other than thin air - a bit more balanced, better design but still not quite there. now you're finally using a properly balanced driver which doesn't chase a single number like XMAX but is rather built for overall performance.
XXX = sumo wrestler. .
LMS = WWF wrester.
B&C = UFC fighter.