Stop Dimming Your Headlights

I hear a lot of people complaining about their headlights dimming to the beat of their music after having a car audio system installed. Depending on what size amplifier you have added, you may notice electrical fluctuations throughout the car, including in your car's performance. Here is a simple and cost effective way to stop or significantly reduce this side effect.
The large amounts of power pulled from the amp have to come from somewhere, so it robs your battery, your alternator, and everything else of power that is connected to your battery. This can put a lot of undue strain on the alternator, and can in many cases result in premature failure. You may even notice a decrease in your car's performance too with larger amps. The ignition components all require a steady amount of voltage and amps to perform correctly, and if this flow is disrupted, you can see a decrease in horsepower. This is directly because power that would have been used to fire the spark plugs is being drained by the amp faster than it it being replenished by the alternator.
The easiest solution to this issue is to add a second battery. This essentially doubles the amount of available power the car has. For around $50.00, you can add a second battery and virtually eliminate the dimming headlights. The amp and other added car accessories (except the head unit) should be run off of the added battery. It is also a good idea to get a battery isolator for the second battery. This allows the alternator to charge the second battery, but does not allow the components attached to the second battery to put added strain on the primary battery, leaving the primary battery to power the car's other electrical systems. An average battery isolator will run you about $50.00-$100.00, but worth the investment for larger systems.
Don't sacrifice your car's performance for sound. Do it right and get great performance AND great sound.