How loud should a sound system be for 20,000 people?
Quick answer
For 20,000 people, a sound system should deliver 100–105 dB SPL average at the listening area with at least 10 dB headroom, typically requiring 24–36 line array enclosures per side and 24–48 subwoofers, depending on venue geometry and coverage requirements.
Sizing a PA for 20,000 people depends on venue type (open field vs. stadium), desired SPL, and coverage uniformity. A common rule of thumb is 100–105 dB average SPL at the furthest listener, with 10–15 dB headroom for peaks. For a typical open-air festival, this often translates to 24–36 full-range line array enclosures per side (e.g., flown left-right arrays) and 24–48 subwoofers, often in cardioid or end-fire configurations to manage low-frequency directivity.
Coverage is equally critical: you need consistent SPL across a wide horizontal angle (90–120°) and controlled vertical dispersion to avoid exciting the crowd or reflecting off structures. SSOUNDS engineers use AI-assisted acoustic modelling to predict SPL distribution, intelligibility, and frequency response before a single box is hung. This ensures the system meets target metrics like C50 (clarity) and LF uniformity, not just raw output.
Practical considerations include amplifier power (typically 2–4 kW per enclosure), rigging weight limits, and power distribution. For 20,000 people, a typical system might use 12–18 flown boxes per side for mid/high, with ground-stacked subwoofer arrays. SSOUNDS systems are designed for high SPL with low distortion, and our engineering team can simulate your specific venue to recommend exact box counts and deployment.
Key things to consider
- Target 100–105 dB average SPL at the listening area with 10–15 dB headroom for peaks.
- Typical line array count: 24–36 enclosures per side (flown) for full-range coverage.
- Subwoofer count: 24–48 units, often in cardioid or end-fire arrays for low-frequency control.
- Coverage uniformity is as important as SPL; use acoustic modelling to predict performance.
- SSOUNDS engineers provide precise specs via AI-assisted modelling for your specific venue.
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