Cadillac CTS-V - Exhaust ?

Sorry if this question has been asked bf, and I did a search didn't see an answer. Okay, my car has kooks long tubes and some small bullet looking converters with no secondary O2s, then a magna flow cat back with the resonator in the center. Not sure why, but the secondary O2 holes are welded shut? Maybe it had to pass vis. inspection somewhere. Any way, has anyone done any interchanging with different exhaust systems? Can it be done without a whole lot of fabricating? My car is fairly quiet, and I would like it to be at least deeper in tone. Not looking for that raspy, high pitched sound. Thought about just changing the mufflers to flows, but maybe I would be better off to just get a mid pipe, that's either an X or H and see how it sounds. Just trying to figure out my options with out doing any welding till I know I like the sound.

Magnaflows with an x and without a resonator will drone. Flowmasters will make it louder, but not flow better. If you want it loud, remove the rear mufflers altogether.

I have stock exhaust with muffler delete. Left the resonator on. Sounds nice and deep. I will be putting headers on soon, so hope the sound doesn't change too much.