When assessing a microphone capsule (mic head), it's important to understand several core performance parameters. These indicators can help determine whether a mic is suitable for your application, whether it's for voice pickup, recording, broadcasting, or noise-sensitive environments.
Frequency response refers to the range of audio frequencies a microphone can accurately capture. A wider and flatter frequency response ensures better performance across low, mid, and high tones. Ideally, a microphone should respond evenly across the full audible spectrum, but different applications might favor certain frequency ranges, such as enhanced mids for voice or boosted lows for instruments.
Sensitivity indicates how well a microphone converts acoustic pressure into an electrical signal. Higher sensitivity means the microphone can detect quieter sounds without needing as much amplification. However, the ideal sensitivity also depends on the amplifier gain and application. For close-talking scenarios, too high sensitivity may cause distortion or pick up unwanted background noise.
Signal-to-noise ratio (SNR) measures the level of the desired signal compared to the background noise generated by the mic itself. A higher SNR means cleaner audio with less hiss or interference. This is especially critical in voice control, surveillance, and recording environments where clarity is important.
Dynamic range describes the difference between the loudest and quietest sounds a microphone can handle without distortion or signal loss. A wider dynamic range allows better performance in situations with sudden loud sounds or subtle details, such as live performance or environmental monitoring.
Phase response refers to how well the microphone maintains the phase relationships between frequencies. Good phase response ensures that complex sounds (like human voice or instruments) are preserved accurately during recording or transmission.
Noise in this context often refers to self-noise – the inherent electrical noise generated by the mic's internal electronics, especially the FET in an electret capsule. A low-noise microphone is preferred for professional recording or sensitive applications like security or broadcasting.
Distortion is usually measured as Total Harmonic Distortion (THD), and sometimes THD+N (which includes noise). It shows how faithfully the microphone reproduces the original sound without introducing unwanted harmonics. The lower the distortion, the more natural the recorded sound will be.
By carefully evaluating these performance parameters, engineers and product developers can select the most appropriate microphone capsule for their device, ensuring optimal sound pickup, minimal interference, and the best user experience.
