The sensitivity consistency of electret microphone elements (mic heads) is a critical parameter that directly impacts the overall performance and reliability of the microphone.
Key Factors in Sensitivity Consistency:
1. Understanding the Basics:
Electret microphones use a permanently charged electret film as the sound-to-electric conversion element. The performance of the mic head, being a crucial part of the microphone, directly influences the sensitivity.
2. Factors Affecting Sensitivity Consistency:
Several factors influence the consistency of electret microphone sensitivity, such as:
- Stability and consistency of the polarization voltage on the diaphragm or backplate.
- Stability and alignment (axial error) between the diaphragm and backplate.
- Coaxiality and consistency between the components (radial error).
- Uniformity in diaphragm tension, thickness, and backplate flatness and smoothness.
- Consistency in the FET amplifier's characteristics, as well as the manufacturing and polarization processes.
3. Manufacturing Process Control:
Ensuring tight control over each production stage is essential to maintaining the consistency of the structural dimensions, material properties, and other parameters across mic heads. The polarization process, including uniform voltage and the stability of the polarization potential after aging, is crucial for consistency. Polarization devices must provide a stable high-voltage electric field and constant polarization current.
4. Testing Sensitivity Consistency:
To evaluate the consistency of electret microphone sensitivity, several experimental methods and testing devices can be used. For example:
- Sound pressure level calibrators and audio analyzers can measure and compare the sensitivity of different mic heads.
- Aging tests and environmental tests under varying temperature and humidity conditions assess the stability of microphone performance.
5. Improving Sensitivity Consistency:
To address factors that affect sensitivity consistency, manufacturers can implement several improvements, such as optimizing the polarization process, enhancing mic head design, and using higher-quality materials. These measures help improve the sensitivity consistency of electret microphones, leading to better overall microphone performance.
Our Electret microphone products state-of-the-art imported production equipment and techniques that ensure unique reliability and sensitivity consistency. The standard sensitivity tolerance is ±2dB, with the option of ±1dB for customers with special requirements, far exceeding the industry standard of ±3dB.
