they do reduce the sound levels, by how much is a depends upon the condition of the end cans and the design of the baffle. A figure of 50% is very hard to define, as a 1dB decrease is barely discernable by the human ear. baffles would normally reduce the sound level output by around 5dB. Seeing as the measurement for a 916 would be at 5000rpm, anthing below this RPM would be quieter too....therefore being realistic, cant you just ride quietley out of your road?
