Decibel Meter Baseline Testing

At the beginning of the week, I found a YouTube video where a guy recorded decibel ratings in his Mustang comparing the FlowMaster Delta Flow 50 mufflers to the Super 44s that I have on my car.  This gave me the idea to do the same as a baseline before I perform any additional sound deadening.  At this point, I already have Luxury Liner on the front floors, under the rear seats, and have sound deadened the driver door (but not the passenger quite yet).

For the most part, my tests were done with the db meter in the cup holder of the center console.  I have my phone in the second cup holder recording video so it was easy to drive around, state out loud the test, and then just record all the figures later.

Cold Idle (A/C Running) - 65.0-66 db

Warm Idle (A/C off) -  62-63 db

2,000 RPM in 3rd - 35 MPH (A/C Running) - 79 db
... At ear level 82 db

3,000 RPM in 3rd - 50 MPH (A/C Running) - 79 db
... at ear level 81 db

2,200 RPM in 4th - No Load (A/C Running) - 79 db
.... at ear level 84 db

2,000 RPM in 4th - 50 MPH - Light Load (A/C Running) 82 db
... at ear level 87

2,500 RPM in 3rd - Light Load (No AC) - 77

3,000 RPM in 3rd - Under Load (No AC) - 80

2,003rd gear 2000 RPM under load 80 db

1000-2750 medium acceleration runs - 85 db

Acceleration Up to 5,000 RPM - 87 db

What is fairly apparent is the decibel level is fairly consistent with the meter in the console but there is more variability when at ear level.  With some of these test, the console showed 79 db for them all but when lifted to ear level, the db was anywhere from 81 to 84.