How loud should a sound system be for 20,000 people?
Quick answer
For 20,000 people, a professional sound system should deliver 100–105 dB SPL average with 10–15 dB headroom (115–120 dB peak) across the audience area, typically requiring 24–36 line array enclosures per side and 24–48 subwoofers depending on coverage and music genre.
Sizing a PA for 20,000 people starts with coverage: you need a system that evenly covers the entire audience area, typically 60–100 meters deep and 80–120 meters wide. SSOUNDS engineers use acoustic modeling to calculate SPL loss over distance (about 6 dB per doubling of distance) and design arrays that maintain 100–105 dB average with peaks up to 120 dB for rock or EDM events. For speech, 95–100 dB average is sufficient.
A practical rule of thumb: for a 20,000-capacity outdoor festival, you'd deploy 24–36 line array boxes per side (e.g., SSOUNDS large-format arrays) flown at 15–20 meters height, plus 24–48 subwoofers in cardioid or end-fire configurations to control low-frequency directivity. For indoor arenas, fewer boxes may be needed due to reflections, but careful delay and EQ are critical.
SSOUNDS systems are engineered for high output with low distortion, using proprietary DSP and amplifier presets to ensure consistent coverage. We always recommend a site-specific design with predictive software—never guess. Factors like wind, temperature, and crowd absorption also affect real-world SPL, so we spec 3–6 dB extra headroom as a safety margin.
Key things to consider
- Target 100–105 dB average SPL with 115–120 dB peak headroom for music; 95–100 dB for speech.
- Coverage depth up to 100 meters requires 24–36 line array boxes per side flown high (15–20 m).
- Subwoofer count: 24–48 units, configured for directivity control (cardioid/end-fire).
- Always use acoustic modeling software (e.g., EASE, Soundvision) for precise design—never guess.
- Add 3–6 dB headroom for environmental factors (wind, temperature, crowd absorption).
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SSOUNDS designs, supplies, installs and tunes professional AVL across Nigeria & Africa.