25mm Cardioid Electret Condenser Microphone Element for Online Recording (Discontinued)

The ECM-B2573UML33-23823 is discontinued and has been replaced by the upgraded model
ECM-B2583UML32-23861.

This 25 × 7.3 mm unidirectional microphone capsule is widely used in broadcasting microphones, live streaming, and professional recording devices. It delivers stable sensitivity, low noise performance, and excellent directional pickup for high-quality audio capture.

Model: ECM-B2573UML33-23823
Dimensions: 25 × 7.3 mm
Directivity: Unidirectional
Sensitivity: -33 dB ± 2
Impedance: 2 kΩ
S/N Ratio: 82 dB
Max SPL: 120 dB
Operating Voltage: 2 Vdc
Frequency Response: 50 Hz ~ 20 kHz
Current Consumption: 200 μA

Request Information / Sample

Tell us your project stage. Our engineering team will respond accordingly.

Lead Time

Samples: 1–3 weeks
Mass production: 2–4 weeks

Customization

Application-based engineering support
Structure / sensitivity / acoustic tuning

MOQ

3,000 pcs
Per model / per production batch

Certification

RoHS & UL compliant
Industrial reliability assured

Technical Specifications

Our 2573 unidirectional large-diaphragm condenser microphone head offers a high signal-to-noise ratio, low noise, high fidelity, strong directivity, and excellent interference resistance, ensuring premium audio quality and reliable performance.

Standard Test Circuit

Test conditions: RL = 15kΩ, Vs = 2V, C = 1μF

Typical Frequency Response

Frequency response covers 50Hz to 20kHz with a strong overall rise. The response increases noticeably in the low end (50–200Hz), then levels out slightly before another significant boost begins around 2kHz. A peak occurs near 5kHz, followed by a rapid high-frequency roll-off.

Dimensions (UNIT: mm)

Appearance Dimension

The capsule measures 25mm in diameter and 7.3mm in height. The rear side features five acoustic ports, each covered with a damping mesh to enhance stability and reduce unwanted resonances.

Reliability Tests

High Temperature Test: Microphone subjected to +80℃ for 100 hours, followed by 3 hours at room temperature.

Low Temperature Test: Microphone subjected to -40℃ for 100 hours, followed by 3 hours at room temperature.

Humidity & Heat Test: Microphone exposed to +55℃ and 85% relative humidity for 100 hours, followed by 3 hours at room temperature.

Thermal Shocking Test: Microphone subjected to [+80℃ 0.5H → room temp 1H → -40℃ 0.5H → room temp 1H] for 10 cycles, then exposed to room temperature for 3 hours.

Vibration Test: Microphone subjected to two hours of vibration in x, y, and z directions with frequencies of 10-55Hz and a 1.52mm amplitude.

Drop Test: Microphone dropped 5 times from a height of 1.0 meter onto a slippery marble floor, without packaging, and still performs normally.

Storage and Operating Temperature Range: Suitable for environments ranging from -35℃ to +60℃.

Sampling Process

Confirm customer requirements:

Review product application, microphone capsule specifications, usage scenarios, and sound quality needs.

Recommend and specify:

Provide recommended microphone capsule models and detailed specifications for customer evaluation.

Sample provision and testing:

Deliver microphone samples for customer testing and feedback purposes.

Optimize and finalize:

Refine microphone design based on feedback, finalize samples, and proceed to mass production upon quality approval.

Quality Assurance

Conducting sampling inspections of incoming materials to ensure compliance with standard requirements.

Performing inspection audits to ensure the stability and control of the entire manufacturing process.

Conducting pre-shipment inspections to ensure that products meet established quality standards.

Acoustic Laboratory

Testing of background noise, sensitivity, frequency response curve, and directionality indicators.

Verification of the impact of different circuits, structural dimensions, materials, and processes on indicators.

Reliability testing at both the new product design stage and the mass production regular stage.

Automatic Workshop

Utilizing fully automated production lines to ensure high efficiency and consistency.

Equipped with state-of-the-art facilities, including a 10,000-level dust-free workshop.

Employing a rigorous 21-step process to guarantee product stability.