How many watts of PA do I need for 20,000 people?
Quick answer
For 20,000 people, you typically need a large-scale PA system capable of 100–110 dB continuous SPL at the listening area, requiring around 40,000–80,000 watts of amplifier power, but wattage alone is insufficient—coverage and headroom matter more.
Sizing a PA for 20,000 people is not just about wattage; it’s about achieving adequate SPL and uniform coverage. A rule of thumb is 1–2 watts per person for outdoor events, translating to 20,000–40,000 watts, but real-world systems often need 40,000–80,000 watts to handle peaks and headroom. For example, a typical rig might use 16–24 large-format line array enclosures per side (e.g., SSOUNDS flagship arrays) plus 16–24 subwoofers, powered by 40,000–60,000 watts of amplification.
Coverage is critical: you need enough boxes to cover the audience area evenly, with 100–110 dB continuous SPL at the farthest listener. SSOUNDS engineers use acoustic modeling software to predict SPL distribution, optimize array configuration, and calculate amplifier power precisely—avoiding guesswork. For 20,000 people, expect a flown line array system with multiple hangs (e.g., left-right plus delay towers) and ground-stacked subs for low-end impact.
Wattage is a misleading spec; focus on system design. A well-designed SSOUNDS system with 50,000 watts can outperform a poorly designed 100,000-watt rig. Key factors: loudspeaker sensitivity, coverage pattern, and DSP tuning. Always consult professionals for accurate deployment.
Key things to consider
- Rule of thumb: 1–2 watts per person for outdoor events, but 2–4 watts is safer for headroom and peaks.
- Target SPL: 100–110 dB continuous at the listening area; plan for 6 dB of headroom above that.
- Typical rig: 16–24 line array boxes per side, 16–24 subwoofers, powered by 40,000–80,000 watts total.
- Coverage matters: use acoustic modeling (e.g., SSOUNDS software) to calculate box count and placement.
- Wattage alone is insufficient; prioritize system design, sensitivity, and DSP optimization.
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