Cheat Sheet

Car Audio For Dummies Cheat Sheet

From Car Audio For Dummies

By Doug Newcomb, Mike Mettler

Setting up the ideal sound system in your automobile starts with understanding the architecture and signal flow of a car audio system. Selecting the proper gauge wire for your system along with reproducing the right frequency range for common musical instruments is essential for creating great sound in your car.

Car Audio System Signal Flow

This diagram shows the layout of a common car audio system and signal flow. The dotted black line shows the path of the preamp audio signal (before it’s amplified), from a head unit, through an equalizer and electronic crossover and to the amplifier. A video signal is also sent from the head unit to a pair of video screens in the back seat area. From the amplifier, an amplified audio signal (the solid black line) goes to each speaker in the system — one amplifier powers a subwoofer. The other amplifier powers a set of component speakers in the front of the car (with the signal first passing through the speakers’ passive crossovers) and a pair of coaxial speakers in the rear of the car. The gray line shows power flowing through a power cable (protected by an in-line fuse) from the car’s battery to the amplifiers.


Wire Gauge Chart for Car Audio Systems

When wiring your car audio system, using the proper gauge wire for an amplifier is critical. To avoid problems and get the best sound, determine the fuse ratings of your amplifiers and their distance from the battery and refer to the following chart to determine the proper power-wire gauge. For example, if your amplifier is drawing 60 amperes of current and the distance to the car’s battery from the amplifiers is 12 feet, locate where the ampere rating along the top intersects with the approximate distance in the middle area of the chart, and then determine the proper wire gauge on the left. (In this example, it would be 8 gauge.)


Frequency Range of Musical Instruments for Car Audio

To get great sound in your car, you need to accurately recreate the sound of musical instruments by reproducing their frequency range. Use this graph to set up the frequency ranges of common musical instruments for your car audio system.