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When to Add Capacitors to Your System

Do the lights in your car dim when the music plays a loud bass note?

Large Wattage Car Audio Systems

MTX Car Audio Capacitors

MTX Streetwire Car Audio Capacitor

Large wattage car stereo amplifiers draw large amounts of current from your vehicle's electrical system. Larger, multiple amp systems are even a bigger drain on your electrical system, in many cases depleting the system's current capacity thereby lowering the voltage far enough that it cannot properly supply the amplifier(s). Adding capacitors can help solve this problem.

Adding Capacitors

Capacitors store electricity as instant power available for your amplifier. If the amplifier draws more current  than is available from the electrical system directly, the capacitor covers the difference up to its stored capacity. The battery is not overloaded and the car voltage remains steady.  The capacitor will smooth out the peaks in current draw from your amplifier during peaks in the music.   The capacitor will help ensure your music does not go flat, but has the dynamic quality you love.

Use Caution

A capacitor's stored current can give quite a shock if mishandled when it is fully loaded. Follow directions closely and ensure the cap is drained before making contact. A resistor or light bulb can be wired across the cap's terminals to allow the capacitor to discharge slowly and safely.

Keep in mind; capacitors do not make your car audio system sound louder. What they do is improve the performance of the system by reducing distortion caused by sudden voltage drops

Large MTX Subwoofer and Amplifier System

Voltage Stability

Capacitors offer some small amount of protection for amplifiers from potentially damaging under-voltage surges over time if you play loud music regularly. But most of the reason for adding capacitors is to keep your car voltage stable. Before considering capacitors, ensure you have adequate battery and alternator power for the total amperage of your audio system, and check your wiring to be sure you have adequate sized wire. Voltage loss may occur if the gauge is not adequate. If your car’s charging system does not supply enough constant current for the combined RMS rating of your amplifiers there is no amount of capacitors that will keep your electrical system from having low voltage issues when run at RMS output.

Sizing Caps

Capacitors come in different sizes typically starting with 1 Farad. The general rule is to add 1 Farad of capacitance for every 1000 watts RMS of system power. Note that it does not hurt to use more capacitance than this rule and many systems use 2 or 3 Farads per 1000 watts RMS.

Mount your capacitors as close to the subwoofer amplifiers as possible to shorten the path required for the surge power. Follow the directions for mounting and wiring closely to ensure safe and efficient use. Keep in mind that continued voltage drops that last more than a second or two might not be helped by the addition of a capacitor. In these instances it may be better to add additional batteries to the system or upgrade the vehicle's alternator.

So consider adding capacitors to your next large audio system before the lights start dimming!

Click HERE to shop for capacitors.

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