What are these speakers that came with my home worth?

What model are the Velodyne subwoofers? Should be printed on the metal plate on the back of the unit such as Digital Drive or Digital Drive Plus.

   The owners of a $9000. REL Studio III and a JL Audio F113 wanted to compare their subs to my subwoofer at the time a Velodyne Digital Drive 18. The combined consensus of the comparison was the F113 coming a close second to the DD-18 but only when fed the manually equalized Velodyne signal. 
   The REL owner sold the Studio III a few days after the comparison. REL has gone through many changes none of which seem to have been directed to their fundamental sub design.

   Since then Velodyne introduced their Plus series followed a few years later by the JL Audio DARO version still lacking extensive manual EQ and a $1900. optional CR-1crossover.
   Reading the SVS Ultimate setup procedure they include three memory EQ presets and a Q adjustment a notable DSP direction. 
   Aged and recently out of production the onboard conveniently remote controlled Velodyne Plus AFAIK is only approached by one or two third party equalization programs. The digitally servo controlled Velodyne DD series still provides one of the lowest levels of distortion and is far from outdated. Third party service is available.