Home theater sound calculator, sound and noise level measurement

SPL CALCULATOR
Speaker Sensitivity:	dB SPL (1 W/1 M)
Amplifier Power:	Watts
Distance:	feet
No. of Speakers:	usually 2, more for multi-channel
Speaker Placement (Choose 1):	Away from walls (or do not consider placement)
	Near a wall (within 2 to 4 feet)
	In a corner (within 18 to 24 inches)
RESULTS
	dB Gain from amplifier
	dB Loss due to dispersion (distance)
	dB Gain from sonic reinforcement (multi speakers)
	db Gain from placement (reinforcement from reflected sound)
	dB SPL at listening postion

Description	Sound Level	Example	Sound Intensity
barely audible	0 dB	Threshold of hearing	0.000000000001 W/m2
	10 dB	Rustling leaf	0.00000000001 W/m2
very quiet	20 dB	Quiet room	0.0000000001 W/m2
	30 dB	Soft whisper	0.000000001 W/m2
quiet	40 dB	Quiet library	0.00000001 W/m2
	50 dB	Average home	0.0000001 W/m2
moderately loud	60 dB	Ordinary conversation, Light traffic	0.000001 W/m2
	70 dB	Vacuum cleaner, Heavy traffic	0.00001 W/m2
very loud	80 dB	Garbage disposal	0.0001 W/m2
	90 dB	Diesel truck (10 m away)	0.001 W/m2
uncomfortably loud	100 dB	Newspaper press	0.01 W/m2
	110 dB	Jet flyover at 300 m	0.1 W/m2
pjavascript:void(0)ainful	120 dB	Threshold of pain, Thunderclap	1 W/m2

Exposure Time	Exposure Level (measured in dB SPL)
8 Hours	90 dB SPL
6 Hours	92 dB SPL
4 Hours	95 dB SPL
3 Hours	97 dB SPL
2 Hours	100 dB SPL
1.5 Hours	102 dB SPL
1 Hours	105 dB SPL
.5 Hours	110 dB SPL
<.25 Hours	115 dB SPL