So I had a Borla Touring catback, and added a 6 x 14 round Magnaflow to it to quiet it down. Then I put ARH headers with high flow cats on and had to remove the Magnaflow. OMG it was painfully loud! I swapped out the Touring muffler for a Borla Pro XS, which did help some but it's still too loud. I want to add a second muffler but the ARH system has a 3.5" front pipe so that is limiting my options. I can put another 6 x 14 round or a 5 x 8 x14 oval Magnaflow in there, or I was looking at a 5 x 9 x 15 oval Vibrant muffler. All these are straight through. I like the Vibrant because it is 304 stainless, Magnaflow's are 409. I have heard good things about their ultra quiet resonators, but not much out there about their mufflers. Anyone ever use one? Wondering if it is as quiet as a Magnaflow.