Shotgun Mic

Shotgun Mic

Principle and Design

Shotgun microphones employ an interference tube to achieve a highly directional polar pattern (supercardioid or lobar). The long, slotted tube rejects off‑axis noise by phase‑cancelling sounds arriving from the sides, isolating dialogue or specific environment sounds from a distance.

Technical Specifications

• Length: Longer tubes yield narrower acceptance angles and higher directivity index.
• Polar pattern: Supercardioid or lobar, with typical pickup angles of 15–30°.
• Frequency response: Emphasizes midrange (50 Hz–20 kHz) for speech intelligibility.

Film Production Applications

Boom operators mount shotgun mics on poles, placing them just out of frame to capture actors’ voices clearly. Wireless variants attach to cameras for run‑and‑gun shoots, though they risk handling noise without proper shock mounting.

Best Practices

• Mounting: Use shock mounts and boom dampers to minimize handling noise.
• Wind protection: Employ blimps, foam windscreens, and furry “dead cats” outdoors.
• Positioning: Maintain consistent distance and angle to avoid proximity effect and tonal shifts.

Comparative Overview

Feature	Lavalier Mic	Shotgun Mic
Directionality	Omnidirectional/cardioid	Supercardioid/lobar
Placement	On talent (clipped)	Boom or camera‑mounted
Visibility	Concealed	Visible on boom
Ambient Rejection	Moderate	High

Trivia

• The “shotgun” nickname stems from the tube’s resemblance to a shotgun barrel with slits. - Pioneered by manufacturers like Sennheiser, Rode, and Audio‑Technica, shotgun lengths vary to suit different directivity needs.