Sound Advisor

Sound Advisor

Experienced building engineers can often detect impending mechanical faults simply by listening with their trained ears. With this in mind the team at Entronix has created their “Sound Advisor” product line. By combining industrial-grade audio capture with the power of the Entronix Energy Management Platform, our Fault Detection and Diagnosis Unit (FDDU) provides statistical failure detection for predictive maintenance of constant-speed AHUs and other HVAC equipment. The Sound Advisor FDDU installs easily and “listens” to your equipment 24/7 with detection and analysis capabilities that far exceed the human ear.

Phase I: Learning

Sound Advisor measures the amount of acoustic energy across 22kHz of frequency bands, using Fourier analysis and Bayesian statistics to create an audio “signature” of the equipment. Just like fingerprints, different pieces of equipment will have different audio signatures, even if the model and manufacturer are identical. The multi-dimensional audio signature allows Sound Advisor to tell if the unit is on or off, operating in one of a number of normal modes, or if the unit is operating in a way that indicates an imminent failure.

Phase II: Fault Detection

After spending a few days or weeks acquiring a baseline for normal operation, Sound Advisor enters detection mode. Now, audio measurements are tested against the statistical baseline generated in Phase I. This analysis provides a confidence-level value representing the likelihood that each measurement is within normal operating parameters. The user can set the threshold confidence level required before announcing a fault to minimize the frequency of false-positives. Upon identifying a failure event, such as a loosening belt or failing bearing, Entronix’s Energy Management Platform logs it and alerts you.


Entronix’s patent-pending Sound Advisor technology provides the next generation of maintenance solutions, prescriptive maintenance. While preventative maintenance continues to provide ROI of over 500% in replacement and energy cost savings, the potential upside of prescriptive maintenance looms even larger, especially when the incremental cost of adding Entronix’ prescriptive maintenance solution is negligible. By reducing maintenance call outs, false alarms and energy consumption, the Entronix Energy Management Platform and Sound Advisor provide even larger savings in energy, repairs and replacement.