LSA or Duration to fine tune glasspacks??

Case in point: Go listen to the exhaust note of an SN95 Mustang with a 4.6 with mufflers before the axle, then listen to an S197 or S550 ('05-up) with a 4.6 or 5.0 and the mufflers at the bumper.

Hint: They do NOT sound the same despite all else being equal (type of muffler, whether or not the cats are there, etc)