Quote Originally Posted by Todd.K View Post
As best as I can figure, the “suppressor rating” is some secret formula math project. Thus nobody can replicate it, nor understand how the formula is weighted.

It appears to be some combination of time, frequency, and sound pressure level.

Something like this is used in industrial hearing safety for exposure limits that include duration. It is suitable for hearing protection concerns over a work shift, may be suitable for how much .22 or subsonic 9mm is actually hearing safe, but it is not an effective way to measure how loud something “sounds” to the human ear.
Years ago I talked to the guys at Gemtech at length about why they dropped their db ratings from their catalog for suppressors.

Basically they were doing it under controlled conditions, in a room with high quality sound meters that gave them the same results every single time. Then the guys at AAC would go shoot their suppressor outdoors on the same rifle and of course get a much lower db reading as a result and then they'd advertise that "real world" rating in their catalog.

Even inside, if you don't have the correct setup, I can get 12 different readings from the same rifle, with the same ammo and even the same shooter with a pretty serious spread. Outdoors I can make a suppressed .22 read like a .308 carbine and a .308 carbine read like a suppressed .22.

This of course makes all those YT videos, even from the good guys, pretty pointless when it comes to suppressor taste tests.