I put in a RARE 2.5 system X- crossover on my convertible. The mufflers that came with the system were a 14" strait through design(Spin Techs). Keep in mind this is a convertible, but the drone was horrible and they were way way to loud for my liking. I bought a set of 14" Dynomax ST mufflers and they were much quieter but I still had drone from 2100 to 3K rpm that drove me nuts. I then went with 16" VT mufflers and I have been very happy with them.
I researched to death about mufflers and the dreaded drone. The problem with the Jim hand data is it is done with with his wagon (Longer pipes) and more importantly 20" mufflers. Videos posted on PY still don't give you an idea of how loud it will be or if you might have drone issue. Size, bends, mufflers, headers, length, Hpipe, Xpipe all effect the sound.
The subject of exhaust itself is very subjective. What is horribly loud to me may be fine with you.
