My Last day with the Extech Sound Meter I took it for a ride into work at FLIR. Although I didnt get to test the exhaust DB output, I was able to test the cabin noise. Range was from high 60's(59 in picture) to low 90's with means between mid 70's and mid/high 80's. Actually kind of high but with the tuning and modifications made to my civic, I would expect a little more noise.
PS-Odometer is exempt. She(Matilda) has about 326,000+ miles on her.