H or X CROSSOVER?

X pipe should be quieter, though the mufflers you choose are worth something here as well. If you use the turndowns instead of extending the tips past the bumper, it will drone a lot more.

My Duster has the 2.5" TTI x-pipe system and the Dynomax Ultra-Flos. I would imagine the super turbos are slightly quieter, though they aren't really THAT loud.

Flowmasters drone a lot.