I. Overview
The MegaSig SS 772-11 is a high-sensitivity, low-noise ear simulator. In electroacoustic measurement, its core function is to simulate the acoustic load conditions of an earplug inserted into the human ear canal or auricle, and to measure the actual acoustic performance of the earphone by accurately simulating the coupling state between the earphone and the human ear.
In terms of structural design, the SS 772-11 adopts a non-removable design that integrates the coupling cavity and preamplifier, making it an extremely stable pre-polarized pressure field measurement microphone kit. Its product positioning is very clear: it is a “high-performance, low-noise” precision sensor specifically designed for audio production line testing of in-ear headphones .
II. Acoustic design conforming to international standards
SS 772-11 strictly adheres to IEC 60318-4:2010 Ed.1.0 (formerly known as IEC 60711). This standard represents the highest guiding principle in global electroacoustics for “obstructed ear simulators for measuring in-ear headphones.” It incorporates a standard 1/2-inch microphone and features a precisely controlled 1260 mm³ coupling cavity volume, ensuring a high degree of consistency and traceability of test data from R&D to production.
III. Superior Acoustic Hardware Specifications
To meet the demanding requirements of modern high-end active noise cancellation (ANC) headphones with their low background noise levels, the SS 772-11 demonstrates impressive hardware specifications:
1. The SS 772-11 boasts extremely low noise floor and high dynamic range as its biggest highlights.
Its typical noise floor is drastically reduced to 9.5 dBA ~ 10 dBA . This allows its overall dynamic range to cover 10 dBA to 113 dB . This means that when engineers test the headphones’ inherent noise floor in an anechoic chamber or a high-specification shielded enclosure, the measurement signal will not be masked by the electronic noise of the instrument itself.
2. The ultra-high sensitivity design
The sensor boasts a sensitivity range of up to 250 mV/Pa (i.e., -12dB ± 2dB re 1V/Pa, with a tolerance range between 200 mV/Pa and 316 mV/Pa). This high sensitivity converts minute changes in sound pressure level into clear voltage signals, significantly improving the signal quality of the backend data acquisition card.
3. Precise and flat frequency response
In stress field testing environments, the SS 772-11 provides excellent wideband frequency response flatness.
- 20 Hz ~ 8 kHz: error is only ±0.5 dB.
- 8 kHz ~ 10 kHz: Error controlled within ±1 dB.
- 10 kHz ~ 16 kHz: error is ±2 dB.
- 16 kHz ~ 20 kHz: The high-frequency error is only ±3 dB. This ensures that everything from the very low bass performance to the ultra-high frequency harmonic details can be faithfully recorded.
IV. Recommendations for Production Line Automation Integration
As an equipment integrator, we place great importance on the stability and ease of use of sensors in factory environments.
- Perfect System Pairing: To achieve the best production line testing results and signal-to-noise ratio, we recommend using the SS 772-11 with the MegaSig PM 0083 IEPE signal conditioner .
- Industrial-grade durability: The device uses an industry-standard BNC interface for signal transmission. It has excellent environmental adaptability, operating in temperatures ranging from -20°C to 60°C and withstanding non-condensing relative humidity from 10% to 90%.
- Maintenance and storage: To ensure the long-term stability of the sensor, it is recommended to store it properly in an environment with a temperature of 25℃±5℃ and a humidity of 50%±15%RH during non-testing periods.
V. Specifications
| Sound field type | Pressure field type |
| Polarization voltage | 0V (pre-polarization) |
| Frequency response | 20Hz – 8kHz ± 0.5dB 8k Hz – 10kHz ± 1dB 10k Hz – 16kHz ± 2dB 16k Hz – 20kHz ± 3dB |
| Dynamic range | 10dB (A) – 113dB |
| Typical background noise | 9.5dB(A) – 10(A) |
| Sensitivity (mV/Pa, dBV/Pa) | 250mV (-12.0dB) ± 2dB re 1V/Pa; (200mV/Pa – 316mV/Pa) |
| Maximum output voltage | 5.6V |
| Coupled cavity volume | 1260mm³ |
| Power supply | 2mA – 10mA (typical 4mA) |
| Equalization method | Post-equalization pressure |
| Interface type | BNC |
| Operating temperature range | -20℃ to 60℃ |
| Storage conditions | Temperature: 25℃±5℃, Humidity: 50%±15%RH (to ensure long-term stability of the sensor) |
| Relative humidity | 10-90% non-condensing |
VI. Summary
The MegaSig SS 772-11 is a precision core sensor designed to address the pain points of testing in modern in-ear headphone production lines.
It perfectly combines the authority of the IEC 60318-4 international standard, an extremely low noise floor of 9.5 dBA, and an integrated, highly reliable mechanical design. For electroacoustic manufacturing teams that demand rigorous quality control and need to accurately detect acoustic flaws in mass production, the SS 772-11 offers unparalleled value for money. It will be an excellent investment for building a modern, standardized audio testing production line to ensure consistent quality for every pair of headphones shipped.