IThe Energy S8.3, on the other hand, is a new release, and no reviewes available. However the manual seems to suggest that the subwoofer uses revolutionary technology and distortion down to almost 0%.
This is what the energy web release for the subwoofer says
"High output and incredible musicality are the result of the materials chosen, a direct result of the patented Elliptical Surround used on all three models. This exclusive surround technology reduces speaker distortion from an average of 14% to nearly 0%, while increasing useable piston area and even includes exclusively designed ribs to eliminate surround deformation. The Elliptical Surround increases speaker efficiency, with greater surface
area and 30% more excursion over the competition."