Here's an interesting video where the exhaust sound is captured on many different muffler systems on a 5.7 Hemi.
I'm getting old. I like mine on the quiet side with a nice burble and maybe a little noise while accelerating. I find that a loud exhaust creates more fatigue for me as a driver. I'm happy with the factory exhaust on both of my Challengers.
Thanks for sharing. Someone went to a great deal of effort. Adding headers may change all those results significantly. An exhaust system that incorporates electronically controlled cut outs / open / close valves would get my attention.