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Piezoelectric Loud Speaker for Harsh Environments
A piezoelectric loudspeaker without any magnetics that can be used in virtually any environment. It provides excellent voice reproduction and operates at a broad frequency range.
Overview
ISL was approached by a customer who was in need of a piezo loudspeaker that could be used in harsh environments, where a traditional magnetic speaker could not be used.
Challenge
Due to the application and the speaker’s environment, ISL had to design a speaker that had no magnetics. The result was for ISL to design a piezoelectric speaker to meet the customer’s application requirements. The speaker needed to operate at a broad frequency range as well as provide voice reproduction.
Solution
ISL designed the PZ-94 speaker. It’s a piezoelectric speaker with an extended frequency range that meets all of the customer’s strict requirements. This speaker is lightweight with a thin profile, but robust enough to handle 50 W (EIA). The PZ-94 speaker utilizes a high strength phenolic cone which provides the resistance to humidity when used in harsh environments.
- Frequency Response: 450 Hz to 20kHz
- Average Sensitivity: 82dB at 1m/1W
- Max. Power Handling Capacity: 50 W (EIA RS426) (8Ω system reference)
- Operating Temperature Range: -40°C – 105°C
- Typical Impedance: Appears as a 1.5μF Capacitor
- Shock Test: 1,000G, 1ms
- Humidity Test: 100% RH (MIL STD 810C; Method 509.1; Salt Fog)
- Weight: 1.10 oz (33g)
Although the PZ-94 speaker was initially intended to be used in military audio applications, they are now being used inside MRI suites as well. Since the PZ-94 speaker lacks any magnetics, it’s one of the few loud speakers that can be used inside MRI suites.
Conclusion
ISL met the customer's need for a piezoelectric loudspeaker capable of operating without any magnetics by developing the PZ-94 speaker. This lightweight, thin profile speaker delivered a broad frequency range and clear voice reproduction while withstanding humidity, shock, and extreme temperatures found in harsh environments. Because the PZ-94 speaker contains no magnetic components, it has since expanded beyond its original military application into MRI suites, where traditional magnetic speakers cannot be used. This project demonstrates how ISL can design specialized audio components that perform reliably in the most demanding environments.
