Boom-cars suck:
Boom cars are also called ground pounders, street pounders, or (rarely) trunk thumpers, and no wonder considering the brain-liquefying power of some of these car stereo systems. A decent home stereo might pump out 200 watts, but boom car units often boast 1,000 watts of power, and systems with 2,000 or even 3,000 watts have been recorded. As a point of reference, the human pain threshold for noise is 120 decibels (dB), but these rolling sonic factories can hit 140 or even 150 dB. Because decibels are measured on a logarithmic scale, the sound level doubles every 10 dB, so (it turns out) 150 dB would be the equivalent of standing next to a 747 with its jet engines at full roar.