Anyone had a DB Exhaust test

I am trying to get an idea about how loud the DB of an exhaust actually is.
so what have your cars been tested at??

something like this
stock vs a cat back on the market
Idling 65 dB 76 dB
Approach exhaust noise (4500 rpm) 86 dB 92 dB
3000rpm 80 dB 86 dB
5000rpm 91 dB 95 dB
4000rpm - 6000rpm response 100 dB 108 dB

But just reading that does not really tell you how differant it is

every 2 db is double the volume, i dunno if that helps