FYI,
I haven't measured the response from these woofers, but the response curve looks quite different than the previous W18 woofers. It appears the surround is thicker than the previous version and this has effected the response between 2500hz and the air resonance in the cone at 4200hz. This may be a good thing, but also makes the new driver incompatible with the 1801 crossover.
Caveat - again, I haven't measured these new drivers yet. Hence, my assertion could be unfounded.
Dave
