I am a dork, so while playing with exhaust recently I used a sound meter app on my phone to measure the difference between a few different exhaust setups. While a sound meter app isn't going to give professional level results, I found it did correlate with what my ears were telling me.

All measurements were taken from a cold start up with the car in the garage and the phone ~35 feet behind the car at the end of the driveway:

• ISR single exit - 88db peak
• Muffler delete - 77db peak
• Tanabe/Revel Medallion axle back - 74db peak

We know the car revs aggressively at startup, and doing this with the car in the garage with a concrete driveway behind it is going to reflect the sound waves. But, I wanted to know volume levels with my specific situation. This also means that another person's measurements are going to be different based upon all the factors involved here.

My personal takeaways:

• While the ISR is great in the car, and reasonably quiet at idle, it is too loud outside the car for my taste and my quiet neighborhood.
• The muffler delete sounds decent, but the frequencies it resonated at caused weird and annoying vibrations in the cabin.
• There is quite a bit of sound deadening in the car. I probably should have already realized this, but this really made it evident. An exhaust like the ISR that is reasonable quiet inside the car can sound much louder outside.

One last note: the Tanabe/Revel axle back is a work of art.....beautiful mufflers and tips.

The ISR is for sale, you can find the listing here: https://www.myg37.com/forums/private...k-exhaust.html