I was checking out these new Boston Acoustics sub's The first one was a SPG 555 with replacable voice coil's
Only 26 Lbs! it uses Neodymium magnet's
3¾ inches of peak-to-peak excursion
Available in 4-ohm and 2-ohm versions
The second Sub was the G5, This sub can be used with a boston acoustics "radiator" that they say will give you a extra 3 db
SPS™ (Soft Part System) removable assembly enables SVC/DVC swaps and field repairs
3-inches of peak-to-peak excursion
Compatible with GTR TunableRadiators™, for increased bass output without added enclosure volume