How does a microphone work? The technology behind sound recording
Microphones are fundamental devices in audio technology that convert sound into electrical signals. This conversion allows us to record, amplify, or transmit voices, music, and other sounds. But how exactly does a microphone work? The answer lies in the conversion of acoustic energy (sound waves) into electrical energy, a process based on different physical principles depending on the type of microphone. In this article, we'll take a look at how microphones work and explain how different microphone types achieve this conversion in different ways.
Basic structure and function
Sound waves hit the membrane
Sound waves emanating from a sound source strike the diaphragm of a microphone. This diaphragm is a thin, flexible plate that is set in motion by the sound waves. This movement is the basis for the conversion of sound into electrical signals. But how exactly does this conversion occur? This is where different types of microphones come into play, each using different technologies to process the acoustic signal.
Conversion to electrical signals
The movements of the diaphragm are converted into electrical signals in different ways, depending on the type of microphone. Here are the most common microphone types and how they work:
Dynamic microphones
Dynamic microphones are one of the most common types of microphones and are often used in live situations or recordings that require high durability and reliability. In a dynamic microphone, the diaphragm is coupled to a coil that moves within a magnetic field. When the diaphragm is moved by sound waves, the coil moves within the magnetic field, generating a voltage. This voltage is the electrical signal produced by the microphone.
Advantages
Robust construction, ideal for use in noisy environments
No external power supply required
Area of application
Stage performances, interviews and studio recordings
Condenser microphones
Condenser microphones use a capacitor, which consists of a diaphragm and a solid backplate. Sound waves change the distance between the diaphragm and the backplate, thus changing the capacitor's capacitance. These changes in capacitance are converted into electrical signals. Condenser microphones require an external power supply, often in the form of phantom power, to maintain the capacitance.
Advantages
Very high sound quality with clear and precise recordings
Ideal for studio recordings and voice recordings
Area of application
Studio recordings, podcasts and professional audio recordings
Electret condenser microphones
A type of condenser microphone where the backplate is permanently electrically charged, making the microphone smaller, cheaper, and suitable for portable devices. These microphones are widely used in smartphones and other handheld devices. Electret microphones offer good sound quality and require less power than conventional condenser microphones.
Advantages
Compact design
Cheaper than conventional condenser microphones
Area of application
Smartphones, portable recording devices and affordable microphones for everyday use
Ribbon microphones
Ribbon microphones use a thin metal foil (the "ribbon") suspended between two magnets. Sound waves move the ribbon, creating a tension. These microphones are particularly sensitive and offer a warm, natural sound, making them ideal for certain audio recordings.
Advantages
Highly sensitive and ideal for natural sound recording
Especially good for soft and subtle timbres
Area of application
Studio recordings, classical music and film productions
Signal amplification and transmission
The generated electrical signal is usually very weak and must be amplified before it can be recorded, amplified, or transmitted. This amplification occurs either within the microphone itself (in active microphones) or in an external preamplifier. The amplified sound can then be sent directly to a loudspeaker or stored in a recording device.
MagicMic™ Wireless Microphone
The MagicMic ™ Wireless Microphone combines classic microphone technology with modern wireless technology to offer a flexible and high-quality audio recording solution. It uses a high-quality microphone capsule to precisely convert sound waves into electrical signals, which are then wirelessly transmitted to a receiver. This technology makes the MagicMic™ an excellent choice for content creators, podcasters, and professional applications where mobility and ease of use are crucial.
Conclusion
Microphones are amazing devices that convert sound into electrical signals, making them an indispensable tool in audio engineering. Whether dynamic, condenser, or ribbon microphones, each has its own advantages and applications. With the MagicMic™, you can benefit from this technology while enjoying the flexibility of a wireless microphone that delivers professional sound quality wherever you record.