KEF REFERENCE 8b delivers exceptional bass precision and control with zero distortion. Only a truly great subwoofer could do justice to THE REFERENCE standards of home theatre, and it does. To experience the full impact of dramatic on-screen effects, bass definition and control are as important as extension. For power with accuracy, REFERENCE 8b sub boasts two 500W Class D amps, each driving a 228mm (9 inch) long-throw, ultra-low distortion driver, connected back-to-back in the heavily braced, acoustically inert cabinet. Only a truly great subwoofer could do justice to THE REFERENCE standards of home theatre, and it does.