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AMPLIFIER POWER REQUIRED CALCULATOR - COPYRIGHT CROWN®
This calculator provides the required electrical power (power output from the amplifier) to produce a desired Sound Pressure Level (SPL) at a given distance, along with an amount of headroom to keep the amplifier(s) out of clip. This tool is useful when designing audio systems with various room sizes and amplifier models. This Javascript calculator requires Microsoft Internet Explorer v4.0+ or Mozilla Firefox v1+ browser.
EXAMPLE: You are designing a system where the farthest listening position from the loudspeaker is 100 meters, and the desired Sound Pressure Level is 85 dB SPL The loudspeaker chosen for the job has a sensitivity rating of 95 dB. With the minimum recommended amplifier headroom of 3 dB, then you need to choose an amplifier that can supply at least 1,995 watts to the loudspeaker.
EQUATION USED TO CALCULATE THE DATA:
dBW = Lreq - Lsens + 20 * Log (D2/Dref) + HR
W = 10 to the power of (dBW / 10)
WHERE:
Lreq = required SPL at listener
Lsens = loudspeaker sensitivity (1W/1M)
D2 = loudspeaker-to-listener distance
Dref = reference distance
HR = desired amplifier headroom
dBW = ratio of power referenced to 1 watt
W = power required
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