Sennheiser E604 Dynamic Cardioid Instrument Microphone Kit, 3-Pack. Includes drum rim clips. he Sennheiser e 604 Microphone is a rugged, cardioid instrument microphone that is specially designed to handle the high sound pressure levels of drums, percussion, woodwind, and brass instruments without distortion. It captures frequencies between 40 Hz and 18 kHz, doing so at sound pressure levels in excess of 160 dB without nasty distortion.