Dave,
I have not tried that app but I have tried a decibel app. Thank you for posting the information.

I have heard different things from different people about the loudness of the straight thru type mufflers. It does seem to matter on the size of the engine and the pipe size like you pointed out. This is why I am thinking of running two round mufflers on each pipe with the x-pipe.

My current OE 2-1/4" type mufflers (no resonators) are at least 12 years old and they are probably burnt/rusted out some over the years. They are fairly loud at idle and quiet at cruise and loud again at WOT. My phone app showed 88-91 decibels at idle from standing around the rear tires and working my way back to the bumper just above the tips. I can't imagine that the phone app is real accurate but it does give me a reference if I do swap out this exhaust this Summer.

Steve,
I have checked out the Accurate websight and I believe that those are 2-1/4" inlet/outlet with 2" tips. NOTE: The stock OE style mufflers are very restrictive (apx 175cfm). The straight thru 2.5" type are in the 500cfm range, but they are louder.

I do like their Magnum straight thru stock looking mufflers but they are a little too pricey for 2-1/4" inlet/outlet and I was told that resonators would be required with the Magnums to keep the noise down.

I am looking at a full 2.5" system from my existing TTi headers back to 2.5" tips. TTi does sell the 2.5" system all the way back and since they designed the headers, then my expectations are that the 2.5 exhaust should bolt up with little to no mounting issues. The exhaust is not my worry, it is the unknown loudness of the straight thru mufflers that I am worried about. I may have to change my plan before I purchase the parts but until then, I need to decide or find out how loud a pair of the round 6"/7" mufflers would be by themselves or with a pair of 3.5"/4" round mufflers (10-12" long max length) are with them.

Thanks for the replies.