Sometimes, you just obligation to crank up the volume. Clunker audio systems must overcome a good deal of ambient noise--a vehicle traveling down the highway in the coterie of other loud engines is surrounded by a high background blare level. Factory-installed head units have a modest extent of amplification (generally about 10 watts per duct or less), and many aftermarket head units have at least Car Audio twice that.

The more power the amp included with your CD or cassette player delivers, the cleaner the safe from the speakers. But be careful--a receiver rated at 50 watts maximum power probably has no more than 20 watts of clean power. For that reason, serious mobile listeners eschew the modest amplifiers built into head units and instead opt for powerful external amplifiers.
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