Amplifier Power to SPL Calculator
Calculate the sound pressure level (dB SPL) at any distance from an amplifier and speaker given the speaker sensitivity rating and amplifier power output.
Results
What is it?
Speaker sensitivity (dB/W/m) tells you how loud a speaker is at 1 meter with 1 watt. Each doubling of power adds 3 dB. Each doubling of distance subtracts 6 dB (inverse square law in a free field). This calculator chains these relationships to predict SPL at any distance, essential for live sound system design, DJ rigs, and PA coverage planning.
How to use
Enter the speaker's sensitivity from its data sheet, the amplifier RMS power, and your target listening distance. Results show RMS SPL at that distance, SPL at 1m for reference, and what you can expect at double the distance (useful for throw calculations in venues).
Example scenario
A line array element has 98 dB sensitivity. Powered by 500W: SPL at 1m = 98 + 27 = 125 dB. At 10m: 125 - 20 = 105 dB SPL � meeting the 100 dB recommendation for a concert venue audience area. At 20m it drops to 99 dB � still acceptable for the back row.
Pro tip
OSHA limits continuous exposure to 90 dB for 8 hours, halving for each 5 dB increase. At 100 dB, the limit is 2 hours; at 105 dB, 1 hour. Concerts at 110 dB front-of-house should limit set lengths accordingly. In permanent installations, target 85�95 dB for speech reinforcement and 95�103 dB for music venues to avoid hearing damage and comply with local noise ordinances.