http://www.audioholi...sd-introductionThat is the driver built in-house by SVS. If I'm not mistaken it was designed by Stephen Ponte after leaving TC Sounds for SVS. You can always ask the V in SVS since he posted above.
Just going by memory here( I left svs in 07, Jim a few months later, and Stephen shortly after Jim) but IIRC we didn't build the NSD series in house. That driver in the link doesn't look familiar at least. Also, a bump in the back plate is usually for coil clearance(not shorting ring/caps).