JBL Subwooferdriver in von schweikert vr10

[Niklas Nord]

What kind of 18" sub is there in this loudspeaker?
Custom built 18" by JBL, kevlar cone

http://www.vonschweikert.com/vrline/SPECS.HTM#vr10
http://www.vonschweikert.com/vrline/VR-10M.HTM
http://www.vonschweikert.com/vrline/VR-10W.HTM