Electret condenser microphones (ECM capsules) come in different output impedances—550Ω, 680Ω, 1kΩ, 2kΩ, 2.2kΩ. These values affect how the microphone interfaces with the device’s input stage. Higher impedance may give stronger signal; lower impedance is better for driving longer traces or noisy environments.
Common device applications
- Headsets & Call Center Microphones: Typically 2.2kΩ for high input-impedance preamps, ensuring clear voice and good sensitivity.
- Two-way Radios, Walkie-Talkies & CCTV / Security Devices: 680Ω–2.2kΩ depending on input stage and trace length, reducing interference and matching embedded codecs.
- Embedded Voice Recorders, Conference Systems & Intercoms: 1kΩ–2.2kΩ, commonly using electret microphones for clear voice capture and desired SNR.
- Aviation / Specialized Communication Headsets: 550Ω or custom, for legacy analog inputs and strict reliability requirements.
Why impedance matters
Output impedance affects signal level, noise, and compatibility with the amplifier or ADC on the PCB. Understanding impedance helps choose the right capsule for reliable, low-noise audio performance.
How we help factory customers select the right capsule
To recommend the most suitable electret microphone for your product, our engineers need some key information from you. This allows us to match your requirements with products that have been mass-produced, proven stable, and received positive feedback.
- Application / Device: What product will the microphone capsules be used for? What is the application field?
- Product Stage: Is the product in development or already in mass production?
- Specific Requirements: What are the key parameters for the microphone capsules? For example:
- Size / form factor
- Sensitivity
- Welding or mounting method
- Signal-to-noise ratio (S/N)
- Maximum sound pressure level (SPL)
- Other special requirements
- Questions or Confusions: What specific points would you like our engineers to clarify or solve?
By providing this information, our engineers can quickly recommend the most suitable electret microphone capsules based on proven products and applications. For a clear overview of how these capsules are used in different devices, see our Electret Microphone Applications page.
