Two months ago, I added a used Aragon 8008ST bought in Singapore to drive the stereo subwoofers of the Apogee minigrands. The 8008 is rated at 200W/400W into 8/4 ohms. The crossover point is 80Hz according to the manual of the Apogee active crossover, and now the Classe Audio DR9 power amplifier and Apogee bass panels are relieved of large signals below 80Hz. The sound is more relaxed and can be played at higher volume.
The 2kW torroidal transformer provided sufficient juice and control of the 2 units of 8" woofers per channel.