A lot of you have asked how we test silencers for our videos here at Silencer Shop. In this post, I'll explain how it's done.
The MIL-STD-1474D is the standard military test to measure potential hearing damage from noise. This is the industry-accepted standard for testing silencers, too. It states that a sound meter is to be placed one meter to the left and level with the muzzle, with the microphone oriented in an upward position. The meter is placed 1.6 meters off the ground.
The sound meter that we use is a Bruel & Kjaer 2270 and has been verified by B&K to accurately measure peak sound levels for firearms.
There has been debate between silencer companies as to whether the location of the microphone changes when a silencer is added to the firearm. Since the muzzle remains in the same location and doesn’t move, some companies test at this location. Others have said that the addition of a silencer changes the muzzle to be the end of the silencer.
In our tests, we have placed the sound meter both at the end of the silencer and at the muzzle of the gun with the silencer attached. Depending on conditions and calibers, we have observed a minimal decibel change. Since individual shots can vary in that range, the difference in testing is insignificant. Therefore, we have moved from testing at the end of the silencer to testing at the muzzle of the firearm for all tests. In addition, we use high quality ammo and the same host guns for each test.
While our numbers may vary from other tests slightly, or from the manufacturers' numbers, there are some important things to remember: Sound levels are effected by elevation, temperature, humidity, ammunition used, firearm used, barrel length, cleanliness of the silencer, and wind speed, among other things. Because there are so many variables, it is not uncommon for silencers to meter differently from test to test.
Also, it is important to remember that there are more factors than just the sound level of a silencer measured at the muzzle. The backpressure, weight, durability, length, attachment method, accuracy, and customer support of the company all matter.
Another important factor is the sound level at the ear, which is why our new videos show that number as well. It is important to note that the ear measurements are affected by the same factors listed for the muzzle testing.
The sound metering videos are offered as an example of how a silencer performs in general and we strive to make the test as accurate as possible.
Remember, there are more to factors to consider when choosing a silencer than just the sound level; don’t get caught up chasing 1-2 dB.