Electret microphone capsules are known for their high sensitivity, compact size, and low power consumption. However, selecting the appropriate sensitivity requires understanding the actual application scenario.
Without a clear understanding of the end-use environment, engineers might face repeated and inefficient testing during product development.
Here, Aoshi Electronics shares some reference guidelines for selecting microphone sensitivity. These are for reference only-final selection should always be verified through actual product testing.
1. Match with Amplifier Gain
If your product uses a high-gain amplifier, you can choose a microphone with lower sensitivity. Conversely, if the amplifier gain is low, you'll need a mic with higher sensitivity. For example, Bluetooth audio modules typically have high gain, so a sensitivity of around -40dB is usually sufficient.
2. Sound-Activated Toys
These applications have low performance requirements. A microphone with around -35dB sensitivity is generally suitable.
3. Microphone Arrays
These require good consistency across units. Choose microphones with sensitivity tolerance within ±2dB.
4. Karaoke (KTV) Microphones
To avoid feedback (howling), it's better to choose mid-range sensitivity, around -40dB.
5. Sound-Controlled Lamps
These mainly require high sensitivity, with little concern for frequency response or distortion. A microphone with sensitivity above -30dB is recommended.
6. Voice-Controlled Devices
Mid-to-high sensitivity is typically sufficient. If sensitivity is too high, noise or false triggering may occur, causing operational issues.
7. Audio Recording Devices
Since most of these have relatively low amplifier gain, high-sensitivity microphones are preferred-typically above -30dB.
8. Security and Surveillance
These applications demand very high sensitivity. We recommend using microphones with ultra-high sensitivity, such as -26dB, to ensure clear audio capture even from a distance or elevated location.
