Changing the stock X-Pipe to the Fabspeed setup with high flow cats results in dramatically healthier tone. Deeper. Louder. Less muffled. All with stock mufflers.
I then added the Eisenmannm Sport and it hits in you in the chest with tone.
It is crazy talk to think swapping stock X for this upgrade lessens rumble.
2009 Space Gray Carbon Leather E90 with DCT, Tech package, and EPS. Mods: Fabspeed 200 cell cats, Xpipe w/resonators and no secondary cats, BPM tune, Euro DCT software, Eisenmann Sport Mufflers, Vorsteiner Rear Diffuser II, SWS8 subs, JL Audio XD400 bridged 2X200W, built in radar