Reflective Sound Cancellation allows for maximum exhaust gas flow while completely eliminating in cabin sound resonance (drone). RSC™ incorporates innovative technologies developed in conjunction with NASA. With limited use of packing materials and no baffles, RSC™ allows for a completely straight and free flowing exhaust path through the RSC™ mufflers.Reflective Cancellation bounces the undesirable sound waves into each other to attenuate the wave and completely eliminate the low frequency tones that create drone. Each RSC™ muffler is tuned to eliminate specific, undesirable sound frequencies allowing only the engine’s desirable exhaust notes to be heard and improving performance.
The B5 S4 in the video has a full APR RSC Exhaust System with an APR Stage III K04 Turbocharger System.
More info on APR’s site.