The D4 utilizes an entirely new capsule specially designed to capture high SPL instruments with extended frequencies below 100 Hz. By employing sub-impulse technology that samples sounds at a rate higher than other mics, the D4 captures a truer image of the original sound than previous generation kick drum mics. Compact and lightweight, yet featuring full-size diaphragms, the D Series microphones employ exclusive Sub-Impulse Technology designed specifically to achieve the true 3-dimensional sound of instruments.Sub-Impulse Technology builds on the principles of the VLM diaphragm design to accurately pick up the subtle nuances of sub-impulse harmonics. These harmonics contribute substantially to the richness of the sound.