Harmonic pulsation / Vibration?????????

mopar340dave said

Terry, have you read what Spintech says about this and if so, what do ya think?

http://www.spintechmufflers.com/index.php?_a=viewDoc&docId=1

Click to expand...

Am I missing something? I have read that link a few times and can find no reference to feeling physical vibrations due to exhaust...they talk about vibration, but in a sound-related sense. ????