1. Background: Real Impact of Low-Frequency Distortion in PA Systems

In Southeast Asia, public address (PA) systems are widely deployed in shopping malls, schools, transportation hubs, and industrial facilities. These environments often involve long-distance signal transmission, high humidity, and multi-device integration, which increase the risk of low-frequency distortion.

Typically occurring in the 20Hz–200Hz range, low-frequency distortion can lead to:

• Muffled sound output
• Attenuated bass response
• Reduced speech intelligibility

From an engineering perspective, the root causes include:

• Magnetic core saturation at low frequencies
• Inefficient signal coupling
• Impedance mismatch in extended transmission lines

2. Technical Approach: Structural Advantages of EI35 Audio Transformers

Full Audio Frequency Coverage

EI35 audio transformers are designed to support a 20Hz–20kHz frequency range, ensuring complete coverage of audible signals. This is particularly relevant for PA systems where voice clarity is critical.

Laminated Silicon Steel Core Design

The EI35 structure utilizes laminated silicon steel sheets, offering:

• High magnetic permeability for efficient signal transfer
• Reduced eddy current loss, improving low-frequency performance

This structure helps maintain stable electromagnetic characteristics during continuous operation.

Three-Winding Configuration

The three-winding design enables flexible signal routing between input, output, and feedback paths, making it suitable for:

• Multi-amplifier systems
• Zoned broadcasting systems
• Pre-amplifier stages

3. Selection Considerations for Southeast Asia

Environmental Stability

Given the region’s high humidity and temperature, transformers must ensure thermal stability and material durability. Silicon steel cores provide consistent performance under typical operating conditions.

Signal Integrity Over Distance

In large-scale PA deployments, maintaining low-frequency signal stability is essential to reduce transmission losses across extended wiring systems.

Balanced Cost-Performance Ratio

The EI35 size (approx. 35mm class) offers a practical balance between compact design and performance, making it suitable for mid-range PA system integration.

4. Engineering Recommendations

To mitigate low-frequency distortion in PA systems:

• Select transformers supporting frequencies down to 20Hz
• Optimize impedance matching across the signal chain
• Use audio transformers for signal isolation at critical nodes

These approaches help improve overall system consistency without increasing design complexity.