[Zeke]

Megaphones by a long shot. The sport muffler has a low tone and the raspyness is regulated by the length of the stub pipes, IMHO. Mine has about half the normal length pipes and it rattles everything and sets off alarms. But, it's really not that loud, just big resonance.

There's no way you can silence straight pipes even with discs unless you restrict the thing until the car won't run well. Sports have just the right amount of backpressure according to the pundits.