I had a single Flowmaster 50 series on an 01 Durango. It sounded great. It had a nice aggressive idle sound but mellowed out on the road with very little drone. That was running through the stock cat converter. Eventually the muffler rusted out and I needed to replace it. I went with a Walker Tuff Turbo because it was significantly cheaper. I was kind of bummed that I would lose that sound. I was surprised when I got the truck back and the sound hadn't changed at all. It still had the same aggressive idle and quieted down on the road. The stock muffler was humongous. Changing to a smaller muffler was what changed the sound more than the brand of muffler.