nwcid, you must have a fortune in just silencers. How does that work on the AR-30? Seems to me when your rounds are hitting 2900 fps, a silencer wouldn't be all that effective.
There are only 4 cans there. 3 are detachable and 1 integral. Then I have one more detachable and 1 more integral coming for a total of 6. So with the new ones just under $4000 in cans and $1200 in taxes.
As I assume you know guns make 2 noises when fired. There is the high pressure in the barrel escaping into the lower pressure air, then the crack of the bullet breaking the speed of sound ~1100fps. Silencers reduce the amount of noise made from the high pressure to low pressure to change but can not and does not effect the bullet speed.
So effectiveness is relative to what you expect. If you expect hollywood quite then you will not be happy with a suppressor on any gun other then a .22 bolt gun with SS ammo. If you have realistic expectations of what a silencer does and what you want to use it for you will be happy.
You will get lots of opinions on hearing safe and what guns sound like. I know when shooting under cover makes a big difference in noise then shooting in the open (99% of what I do).
Basically the silencer takes out the boom of the pressure change. The bigger the muzzle blast the more noticeable difference a silencer makes. Even with standard ammo while using the silencer there is a nice tone that is not unpleasant to the ear. I say it would be similar to someone shooting a .22lr at 50-100 yards away.
The argument you will hear all the time is that even if the noise is not painful or unpleasant that does not make it hearing safe. I would say it is probably true but I know I listen to my stereo louder and longer then the noise of my suppressed guns.