How to Measure the Audio Performance of Acoustic LED Screens？

Introduction

Acoustic LED screens are revolutionizing audiovisual integration by delivering stunning visuals and allowing sound to pass directly through the display surface. While their visual performance is often the primary focus, evaluating their audio performance is equally essential—especially for theaters, studios, and live event venues where acoustic LED sound quality is a top priority.

To ensure that sound clarity and consistency meet professional standards, AV integrators and engineers must adopt systematic measurement techniques for audio output. This article will guide you through the key metrics, tools, and processes involved in measuring the audio performance of acoustic LED screens.

Why Audio Performance Matters in Acoustic LED Displays

The unique value proposition of acoustic LED screens lies in their sound-permeable design, which allows loudspeakers to be installed directly behind the screen. This integration ensures:

• Better alignment between sound and visuals

• Minimal obstruction or reflection

• Immersive, front-firing sound

However, improper setup or poorly calibrated systems can degrade sound quality. Measuring audio performance ensures that your installation delivers on its acoustic potential.

Key Metrics for Acoustic LED Sound Quality

When evaluating acoustic LED systems, these five metrics are the most critical:

1. Sound Transmission Loss (STL)

This measures how much sound is blocked or absorbed by the screen material. Acoustic LED screens typically achieve a sound transmission rate of over 90%, meaning only a minimal amount of sound is lost when passing through the perforated surface.

How to Measure STL:

• Use a calibrated sound source behind the screen

• Place a decibel meter in front of the screen

• Compare sound pressure levels (SPL) with and without the screen in place

The closer the SPL readings, the better the sound transparency of the screen.

2. Frequency Response

This indicates how accurately the screen reproduces audio across the full range of frequencies (20 Hz to 20 kHz). Flat or even response curves indicate balanced sound without excessive dips or peaks.

Tools Required:

• Measurement microphone

• Real-time analyzer (RTA)

• Audio interface

Method:

• Play a pink noise signal through the speaker system

• Record and analyze the output through the microphone

• Observe the uniformity across low, mid, and high frequencies

3. Speech Transmission Index (STI)

Especially relevant for theaters and conference venues, STI measures how intelligible spoken words are when projected through the screen.

How It’s Measured:

• Use a standardized STI testing signal and playback device

• Measure received signals at various seating positions

• Score ranges from 0.0 (bad) to 1.0 (excellent)

STI scores above 0.6 are generally considered acceptable for performance venues.

4. Harmonic Distortion (THD)

THD measures how much the screen affects the fidelity of the original sound signal. Lower distortion means better sound reproduction.

Process:

• Play a sine wave sweep through the speaker system

• Use an audio analyzer to compare input and output signals

• Look for minimal additional harmonics or noise

For professional-grade audio, THD values should ideally be below 1%.

5. Sound Pressure Level (SPL) Uniformity

This metric evaluates whether the sound volume is consistent across the entire audience area. Uneven SPL distribution can negatively impact the listening experience.

Procedure:

• Measure SPL at multiple points (center, sides, front, and rear)

• Use an SPL meter or RTA system

• Aim for variations no greater than ±3 dB across zones

Acoustic LED-Specific Considerations

Perforation Pattern

Different acoustic LED screens have varying micro-perforation densities. The pattern and spacing directly impact frequency response and transmission efficiency. Screens with denser and evenly distributed perforations offer better sound clarity without compromising image quality.

Speaker Placement

Proper speaker positioning behind the screen is critical. For best results:

• Align speakers with key visual elements (e.g., faces or instruments)

• Use time alignment and EQ to ensure phase coherence

• Avoid obstructions that could block sound pathways

Environmental Acoustics

Room acoustics significantly affect the performance of an acoustic LED screen. Hard surfaces may reflect sound, while soft furnishings may absorb certain frequencies. Use acoustic treatment as needed to ensure a consistent soundstage.

Recommended Tools for Accurate Measurement

• dB SPL meters (Class 1 or 2)

• Omnidirectional measurement microphones (e.g., Earthworks M30, NTI MiniSPL)

• Audio analyzers and software (Room EQ Wizard, SMAART, ARTA)

• Test signals (pink noise, sine sweeps, STI files)

Best Practices for Installation & Calibration

1. Test early during setup, before securing all panels.

2. Calibrate in sections, especially for modular displays.

3. Use real-world content, such as music or video clips, to supplement measurements.

4. Validate performance from multiple audience viewpoints.

These practices ensure that the measured sound quality aligns with what the audience will experience in actual use.

Conclusion

To fully leverage the benefits of acoustic LED screens, it’s essential to understand and evaluate their audio performance with precision. From STL to STI, using the right tools and techniques enables you to optimize sound clarity, consistency, and alignment—turning any installation into a truly immersive environment.

If you’re designing or upgrading a theater, studio, or event venue, Durway provides end-to-end expertise in acoustic LED sound quality calibration and measurement. Visit www.durway.com to learn more or request technical support from our AV integration specialists.