1w/1m spec is not a measured output... its the most misconciving spec besides xmax... Im telling you simply put you want a more linear more compliant driver.. lower MMS higher VAS but with a good b/l and low power compression... the stuifness of the suspension makes a difference in output in the same box same power etc.... to get the same output with more MMS and a lower VAS you need a larger box or more power...
check out hte acoustic elegance AV 15.. get a dual 2ohm coil and with 1200 is going to be one of the loudest woofer you can get, just be mindful of how high you tune and how big your box is...