When repeatability and speed need to coexist in acoustic validation, even small inefficiencies in your measurement chain can compound. Whether you're validating mobile devices, audio electronics, or acoustic transducers, your microphone should not be the variable.
The GRAS 40PO-L and 40PO-H are reference microphones specifically designed to streamline validation and verification workflows—offering predictable, flat response and minimal setup complexity.
Here’s why engineers integrating acoustic measurement systems trust the GRAS 40PO series:
1. Fixed Sensitivity—No More Manual Input or Calibration Drift
Every 40PO-L and -H microphones ship with a fixed, factory-defined sensitivity with an extremely tight tolerance (±0.2 dB). This means you avoid the need for unit-specific calibration,TEDS handshaking, or unit-specific compensation files. In practice:
· No entering mic sensitivities manually
· No calibration correction management
· Reduced chance of measurement error during bench swaps
That translates into faster setup, fewer mistakes, and tighter data alignment across setups and teams. For example, once your system is calibrated for one of your 40PO-L or 40PO-H microphones, then it is already calibrated for any other microphone of the same type, without the need for recalibration.
2. Flat, Equalized Response—Out of the Box
The 40PO series is pre-equalized to deliver a flat frequency response over its designated bandwidth. There's no need to load individual correction curves or apply DSP compensation downstream. This ensures that:
· Every microphone matches your expected baseline
· Pass/fail decisions are not influenced by mic variance
· Engineers can trust the raw output without extra tuning
For acoustic QA and validation tasks, this adds reliability and confidence to every test cycle.
3. Two Optimized Dynamic Ranges for Modern Test Demands
40PO-L covers 30 dBA to 128 dBA ideal for situations where the lowest noise floor is needed for the test.
40PO-H is optimized for higher sound pressure levels, with a dynamic range from 36 dBA and up to 138 dB enabling
Both versions are mechanically identical, allowing easy model swapping without fixture redesign—supporting test setup that need flexibility to adapt to constantly evolving test demands.
4. Plug-and-Play Compatibility with CCP and 48 V Phantom Power
Whether your system runs on Constant Current Power (CCP) or Phantom Power, the 40PO series integrates easily—no custom interfaces required. This enables fast deployment into:
· R&D validation benches
· Custom QA fixtures
· Audio hardware verification rigs
It also futureproofs your setup by staying agnostic to front-end hardware, a critical factor in evolving lab environments.
5. Ultrasonic Testing Capabilities
Both the 40PO-L and 40PO-H have a frequency range that extends up to 40 kHz, way above the human audible range. This follows the current testing demands of many consumers electronic devices that are now required to be tested in the ultrasonic range for applications such as Hi-Res certification, more thorough Total Harmonic Distortion (THD) tests, ultrasonic presence detection, distance measurement, among others.
Consistency Across Units for Confident Scaling
When multiple benches or setups are in play, small variations can snowball into large QA gaps. The 40PO series minimizes these issues with:
· Unit-to-unit uniformity in acoustic performance
· No need for sensitivity matching or TEDS reading
· Consistent results over time, with unmatched environmental stability
That’s what makes these microphones well suited for engineers who need measurement stability across repeated tests, products, or test sites—without the burden of daily recalibration.
Built for Engineers Who Need Precision Without the Complexity
The GRAS 40PO series was engineered for environments where setup time matters, but measurement quality can’t be compromised. Whether you're scaling QA capacity or locking down a high-confidence validation rig, these microphones deliver streamlined integration, clean response, and consistent acoustic behavior—right out of the box.
Learn more about each model: GRAS 40PO-L and GRAS 40PO-H
