Democracy Dies in Derpness


WaPo has published an extremely inaccurate opinion piece about the recent Virginia Beach shooting and suppressors for firearms. In her essay, Juliette Kayyem makes the ridiculously false claim that “a suppressed gunshot can sound like a chair scraping on the floor.” It appears that she’s seen too many Hollywood movies in which the sound of suppressed gunfire on films’ soundtracks were special effects added during postproduction and recordings of real gunfire and that she has little (on no) experience with real world suppressed firearms.

(BTW, based on my experience being involved in the development of theatre sound equipment when I was VP of Engineering at JBL, I doubt that many theatre sound systems can reproduce the sound of gunfire as loud as the actual muzzle blast without being damaged.)

When Hiram Percy Maxim began marketing exhaust quieting devices for internal combustion engines and firearms over a hundred years ago, his brand name for them was Silencer. That name stuck as a generic term in Europe for engines and worldwide for firearms. In North America, we call them mufflers on engines. The generic technical term of art for them is suppressors.

A suppressor is what we engineers call an acoustical low-pass filter. It permits exhaust gas to flow through (in the case of firearm suppressor to provide thrust for the bullet) but tends to reduce the level of high-frequency components in the impulse of the exhaust. If a suppressor worked “perfectly,” there would be nothing in the exhaust except a steady, non-varying flow of exhaust gas, but in order to become more effective at low frequencies, the suppressor must become larger to allow it to attenuate longer wavelength sounds.

An unmuffled engine on a lawn mower is roughly as loud as a series of gunshots, and the size of a lawn mower muffler is roughly the same as a suppressor that can be handled on the muzzle of a firearm. The Gentle Reader should not be surprised that suppressed firearms are typically about as loud as lawn mowers. My lawn mower is noticeable louder than a chair scraping across the floor.

While I’m on the Pro-Second-Amendment side of the gun control debate, I do recognize that there are reasonable points to be made on both sides of the gun control debate. Thus, neither side should have to resort to provably false claims.

Truth is a stronger foundation than a lie.

Democracy Dies in Derpness.