Microphone Basics, Types, and Uses

Microphones

  • Dynamic

    • Rugged, good for loud sources.

    • Key Features: Durable, handles loud sounds, less sensitive

    • Best Uses: Live sounds, drums, amps, vocals

  • Condenser

    • Sensitive, excellent for vocals and ambiance (Phantom Power)

    • Key Features: Sensitive, detailed, wide frequency range

    • Best Uses: Studio vocals, acoustic instruments

  • Ribbon

    • Key Features: Smooth, vintage sound, bidirectional

    • Best Uses: Vocals, brass, room ambience

Phantom Power

  • DC electrical voltage is supplied through balanced XLR microphone cables to power the active electronics inside certain microphones

  • Which Microphones Use Phantom Power?

    • Condenser microphones

    • Electret condenser microphones

Shotgun

  • Highly directional, ideal for dialogue outdoors.

  • Reject unwanted ambient sound from the sides and rear

  • Accessories like windshields further reduce wind noise for clear recordings

  • Key Characteristics

    • Uses a long interference tube to achieve its narrow pickup pattern

    • Commonly used on boom poles for film, TV, and video production.

Lavalier

  • Small, discreet, used for close-miking talent.

  • Typically clipped to clothing or hidden on the body, allowing for hands-free operation and minimal visual intrusion, making them ideal for film, television, theater, interviews, and live presentations.

  • Placed close to the mouth

Sennheiser MKH416

  • Outdoor shotgun microphone valued for its durability, moisture resistance, and focused sound capture in noisy environments

  • Highly directional pickup for excellent isolation of dialogue and rejection of side and rear noise

  • Rugged, compact build suitable for use on boom poles or camera mounts in the field

  • Requires 48V phantom power and connects via standard 3-pin XLR

Sennheiser MKH50

  • Indoor cardioid microphone

  • Highly directional, minimizes off-axis noise and room reflections.

  • RF condenser design: Ensures low self-noise, high sensitivity, and reliable performance in varying humidity.

  • Requires 48V phantom power

Microphone Techniques

Proximity Effect

  • Bass boost when closer to source

  • The closer the source gets to the mic, the more pronounced the bass boost becomes.

  • Does not occur with omnidirectional microphones.

Polar Patterns

  • Control a microphone’s directionality

  • Omnidirectional

    • Description: Picks up sound equally from all directions

    • Typical Use Cases: Room/ambient recording, interviews.

  • Cardiod

    • Description: Most sensitive at the front, rejects sound from the rear, heart-shaped pattern

    • Typical Use Cases: Film, stage, noisy environments

  • Supercardiod

    • Description: More directional than cardioid, with a tighter front pickup and small rear lobe.

    • Typical Use Cases: Film, broadcast, isolating sources.

  • Hypercardiod

    • Description: Even narrower front pickup than supercardioid, larger rear lobe.

    • Typical Use Cases: Film, broadcast, isolating sources.

  • Shotgun

    • Description: Extremely directional, uses an interference tube to focus on sound in front, rejects sides.

    • Typical Use Cases: Film/TV dialogue, outdoor use.

  • Bidirectional

    • Description: Picks up sound equally from front and back, rejects side.

    • Typical Use Cases: Duets, interviews, stereo techniques

Boom Operation

  • Proper handling and position are essential for capturing clear, natural dialogue while staying out of the camera frame.

  • Mic Positioning

    • Hold the microphone as close to the talent’s mouth as possible without being seen on camera

    • Typically placed a few inches to a foot above and slightly ahead of the actor’s head.

    • Overhead booming is preferred for natural sound, but boom from underneath is an option if overhead isn’t possible.

  • Angle and Aim: Aim the mic toward the actor’s nose or mouth at a slight angle

  • Movement: Follow actors’ movements or shift between speakers by rotating or moving the boom pole as needed

  • Handling: Use both hands where the front arm supports the weight while the rear arm steers and cues the mic

  • Noise Control

    • Use a shock mount to isolate the mic from vibrations

    • Secure cables to the pole and avoid jewelry or anything that might cause noise

  • Monitoring: Always wear headphones to monitor audio quality and adjust the mic position in real time

  • Blocking: Coordinate with the director and camera crew during rehearsals to plan mic placement and avoid entering the frame or casting shadows

Lavalier Techniques

  • Involves careful placement (often on the sternum), secure mounting, cable management, and sometimes creative concealment, all to achieve clear, consistent, and discreet audio capture.

  • Sternum Placement: Place the mic capsule over the center of the sternum for a natural, balanced sound.

  • Upside Down Mounting: Mount the lav mic upside down to reduce plosives and minimize distortion

  • Clothing Attachments

    • Common spots include the lapel, collar, or tie knot.

    • Keep the mic as close to the mouth as possible for the best signal-to-noise ratio.

  • Hiding the Mic: Conceal the mic under clothing using tape or special mounts, but avoid heavy layers that muffle sound.

  • Cable Management: Loop and secure the cable to reduce handling noise and avoid accidental tugs.

  • Consistent Distance: Maintain a steady distance from the mouth to ensure consistent audio quality even if the talent moves their head.

  • Creative Placement: Lavs can be hidden in hair, wigs, or costume seams when necessary.

  • Double Miking: Use two lavs for redundancy in high-stakes situations or to capture backup audio

Recording Dialogue

Mic Placement

  • Above talent, angled down.

    • Helps capture clear, natural sound while minimizing plosives, mouth noises, and unwanted room reflections.

    • Tens to retain more high-frequency detail, resulting in a brighter, more articulate recording.

    • Keeps the microphone out of camera frame, reduces the risk of picking up breath and sibilance directly and can help reject noise from below.

Room Tone

  • Recording ambient sound of the location — communicate with the assistant director to ensure there is time for it

  • Used for seamless audio edits

  • Ensure the set is quiet and the mic setup matches the scene

Multiple Speakers

  • Lavaliers

    • Best For: Multiple, moving, or overlapping speakers.

    • Consistent, isolated audio per person.

  • Multiple Boom Operators

    • Best For: Complex Scenes, wide coverage needed.

    • Each operator covers assigned speakers

  • Boom Pole Movement

    • Best For: Two or few speakers, limited crew.

    • Requires anticipation and quick cueing

ADR (Automated Dialogue Replacement)

  • A production audio mixer’s job is to avoid this as much as possible

  • Process of re-recording dialogue in a studio after filming, used when the original on-set audio is unusable due to noise, technical issues, or performance problems.

  • Time-consuming, costly, and challenging for actors to match the original emotion and lip sync.

  • Clean, well-recorded production sound preserves the authenticity of performances and saves time and resources in post-production.