Introduction

Microphones are essential tools in audio production, capturing sound from various sources for recording, broadcasting, and live performances. Understanding the different types of microphones, their specifications, and their applications is crucial for achieving high-quality audio. In this blog post, we will explore the differences between dynamic and condenser microphones, discuss various polar patterns, and examine key microphone specifications that impact recording quality. 

Dynamic vs. Condenser Microphones

1. Dynamic Microphones

Definition: Dynamic microphones are robust and versatile microphones that use a diaphragm attached to a coil of wire, which is placed within a magnetic field. When sound waves hit the diaphragm, it vibrates, causing the coil to move within the magnetic field and generate an electrical signal.

Characteristics:

• Durability: Dynamic microphones are known for their rugged construction, making them ideal for live performances and situations where they may be subjected to rough handling.

• Sound Pressure Handling: They can handle high sound pressure levels (SPL), making them suitable for loud sound sources, such as guitar amplifiers and drums.

• Frequency Response: Dynamic microphones typically have a limited frequency response compared to condenser microphones, often ranging from 40 Hz to 15 kHz. This can make them less sensitive to high-frequency details.

Common Uses:

• Live sound reinforcement (e.g., vocals, instruments)

• Recording loud sound sources (e.g., drums, guitar amps)

• Broadcasting and podcasting

Examples:

• Shure SM58: A legendary dynamic microphone known for its durability and vocal performance.

• Sennheiser e835: A versatile dynamic microphone suitable for vocals and instruments.

2. Condenser Microphones

Definition: Condenser microphones use a diaphragm placed close to a backplate, forming a capacitor. When sound waves hit the diaphragm, it causes variations in capacitance, resulting in an electrical signal. Condenser microphones require an external power source, typically provided by phantom power from an audio interface or mixer.

Characteristics:

• Sensitivity: Condenser microphones are more sensitive than dynamic microphones, capturing a wider range of frequencies and subtle details. Their frequency response typically ranges from 20 Hz to 20 kHz.

• Sound Quality: They are known for their clarity and accuracy, making them ideal for studio recordings.

• Fragility: Condenser microphones are generally more delicate than dynamic microphones and may not withstand rough handling or high SPLs as well.

Common Uses:

• Studio recording (e.g., vocals, acoustic instruments)

• Voiceovers and podcasts

• Ambient sound capture

Examples:

• Audio-Technica AT2020: A popular entry-level condenser microphone known for its quality and affordability.

• Neumann U87: A high-end studio condenser microphone renowned for its exceptional sound quality and versatility.

Polar Patterns

Polar patterns describe how microphones respond to sound from different directions. Understanding polar patterns is essential for selecting the right microphone for specific recording situations.

1. Cardioid

Description: Cardioid microphones are most sensitive to sound coming from the front and reject sound from the sides and rear. The polar pattern resembles a heart shape, hence the name "cardioid."

Applications:

• Vocals in live performances

• Instruments in studio recordings

• Podcasting and broadcasting

Advantages:

• Reduces background noise and feedback

• Focuses on the sound source directly in front of the microphone

2. Omnidirectional

Description: Omnidirectional microphones capture sound equally from all directions. They are sensitive to sound from the front, sides, and rear, making them ideal for capturing ambient sound.

Applications:

• Recording choirs and ensembles

• Capturing room ambiance

• Interviews with multiple speakers

Advantages:

• Provides a natural sound by capturing the environment

• Useful for situations where the sound source may move around

3. Bidirectional (Figure-8)

Description: Bidirectional microphones capture sound from the front and rear while rejecting sound from the sides. The polar pattern resembles a figure-eight shape.

Applications:

• Duet vocals or instruments

• Interviews with two speakers facing each other

• Room ambiance capture in stereo recordings

Advantages:

• Captures sound from two sources while minimizing background noise from the sides

• Useful for creating a sense of space in recordings

4. Other Polar Patterns

• Supercardioid: Similar to cardioid but with a narrower pickup pattern and some sensitivity to sound from the rear. Useful for isolating sound sources in noisy environments.

• Hypercardioid: Even narrower than supercardioid, with a more pronounced rear pickup. Often used in film and theater applications.

Microphone Specifications

When selecting a microphone, several key specifications should be considered to ensure it meets your recording needs.

1. Frequency Response

• • Definition: Frequency response refers to the range of frequencies a microphone can capture, typically measured in hertz (Hz). It is represented as a graph showing the microphone's sensitivity across the frequency spectrum.

  • Importance: A microphone with a wide frequency response can capture more detail and nuance in sound. For example, a microphone with a frequency response of 20 Hz to 20 kHz can effectively capture the full range of human hearing, making it suitable for various applications, from vocals to instruments.

2. Sensitivity

• • Definition: Sensitivity measures how effectively a microphone converts sound pressure into an electrical signal, usually expressed in millivolts per pascal (mV/Pa). Higher sensitivity means the microphone can pick up quieter sounds.

  • Importance: Microphones with high sensitivity are ideal for capturing soft sounds, such as whispers or delicate acoustic instruments. Conversely, lower sensitivity microphones may be better suited for loud sound sources, as they can handle higher SPL without distortion.

3. Maximum SPL (Sound Pressure Level)

• • Definition: Maximum SPL indicates the highest sound pressure level a microphone can handle before distortion occurs, typically measured in decibels (dB).

  • Importance: Understanding the maximum SPL is crucial for selecting a microphone for specific applications. For instance, dynamic microphones often have higher maximum SPL ratings, making them suitable for loud sources like drums or guitar amplifiers, while condenser microphones may have lower ratings and are better for quieter sources.

4. Impedance

• • Definition: Impedance refers to the resistance a microphone presents to the audio signal, measured in ohms (Ω). Common microphone impedances include low (below 600 Ω) and high (above 600 Ω).

  • Importance: Low-impedance microphones are generally preferred for professional applications, as they can drive longer cable runs without significant signal loss. High-impedance microphones may be more susceptible to noise and signal degradation over distance.

5. Self-Noise

• • Definition: Self-noise is the inherent noise produced by the microphone itself, typically measured in dB A-weighted.

  • Importance: A lower self-noise rating is desirable, especially for studio recordings, as it allows for cleaner recordings without unwanted background noise. Condenser microphones often have lower self-noise compared to dynamic microphones, making them suitable for capturing subtle details.

Conclusion

Understanding the different types of microphones, their polar patterns, and key specifications is essential for achieving high-quality audio recordings. Whether you choose a dynamic or condenser microphone, knowing how to select the right microphone for your specific needs will enhance your recording experience and ensure that you capture the best possible sound. By considering factors such as frequency response, sensitivity, maximum SPL, impedance, and self-noise, you can make informed decisions that will elevate your audio production to the next level.