The CrashGuard and CrashGuard 421 are unique sound-shielding devices that prevent bleed from cymbals and other sounds from entering the drum microphone. Once in place, the CrashGuard surrounds the microphone with a sonic barrier. By reducing the spill from the cymbals, more of the drum sound can be captured. This makes it easier for the engineer to add EQ or increase level without accentuating the sound of the cymbal.