Electret Microphones

The process for requesting a sample for electret microphone capsules involves these steps:

1. Requirement Confirmation: Share details about your product's application, usage, size, and sound quality needs.
2. Recommendation and Review: Our sales engineers recommend suitable models and provide specifications.
3. Sample Shipment: After confirming the model, we prepare and ship the samples.
4. Testing and Feedback: Test the samples and give us your feedback.
5. Optimization: We adjust the microphone capsule based on your feedback.
6. Final Approval: Approve the final sample before production.

Microphone sensitivity ratings, expressed in decibels (dB), indicate the device's ability to capture sound. Higher negative values represent greater sensitivity. For instance, a sensitivity rating of -30 dB is higher than -40 dB.

There is no fixed standard for microphone sensitivity; it depends on the application. Higher sensitivity captures sound more accurately but can lead to noise and distortion. Choose sensitivity based on the environment:

• High sensitivity for faint or distant sounds.
• Low sensitivity to reduce noise interference.

Selecting the right sensitivity requires balancing these factors for optimal performance. For more information, visit How to Choose the Sensitivity of Electret Microphones.

Due to the high output impedance (several hundred megaohms) of the capacitive sound sensor in a microphone capsule, it cannot directly match with external amplifier circuits. The output signal is also extremely weak, making it difficult to interface with external amplifiers.

A Field Effect Transistor (FET) is included inside the microphone capsule to address these issues. The FET has high input impedance and low output impedance, allowing it to match the high impedance of the capacitive sensor with external circuits and amplify the weak signal for better compatibility with external amplifiers.

Adding a FET inside the microphone capsule ensures optimal matching and performance between the capacitive sound sensor and the external amplifier circuit. The FET typically requires a power supply voltage ranging from 1.5 volts to 4.5 volts.

Electret microphones find widespread use in lavalier and head-worn microphone configurations due to their compact size and versatility. They offer the flexibility to cater to different preferences, such as the choice between large and small diaphragm designs to meet varied recording needs.

Large diaphragm microphones are favored for their ability to capture rich and detailed sound, making them ideal for studio recordings and vocal performances. In contrast, small diaphragm microphones excel in capturing transient sounds and high-frequency detail, making them suitable for recording acoustic instruments and capturing natural ambiance in live sound reinforcement settings.