Mylar diaphragm speakers (20-57mm) have become the preferred choice for security and education equipment due to the following core advantages:
Ultra-Thin Profile: 3-8mm thickness for concealed installation
Voice Optimization: ±2dB flat response in 1.5kHz-5kHz range, simulating teacher's vocal characteristics
Environmental Durability: IP52 dust/waterproof rating (EN60529 standard)
Typical Application Scenarios
Campus Security Systems
Emergency broadcast terminals: 57mm unit achieves 90dB@1m SPL, covering 200㎡ classrooms
Digital class signs: 20mm micro speaker with TTS voice broadcast, <0.3W power consumption
Intelligent Surveillance Devices
Intercom cameras: 40mm dual magnetic circuit design eliminates motor EMI
Alarm columns: Waterproof metal mesh + explosion-proof diaphragm, operational at -30℃