The problem is a bit complicated to explain but as a whole, I would say that as long as you understand the basic principles of the mobile electronics platform and how your sound system choices will impact it, you can do whatever you please. Let me explain. The actual draw of your amplifier is normalized over time to a level much less than the listed max. The current will max out only during peak moments, such as when the bass hits. During those times, it's your battery that supplies the peak power while the alternator charges it back up. A strong battery makes all the difference. If your battery is weak or undersized, the sudden demand can overload and damage your vehicles wiring and alternator. Additionally and as a word of caution, some amplifiers (usually older units) can be damaged if the applied voltage drops below a certain point for even a moment. Ever heard Orion amps called O-fryin? Whenever I install true-300 watt or larger systems, I talk to the customer and explain the need to "reinforce" the OEM electrical system and suggest some options. The first is to install a high demand battery such as the Optima (red top) which can be found for as little as $79. Most installers swear by them. The second is to upgrade the factory power cables, especially the chassi ground at the battery. Don't remove the factory ground strap but add another from the battery that's at least 25% larger than the max current of the sound system you plan to install. This site has calculators to help you determine the max current and wire gauge. On larger systems, I also suggest properly installed power caps. Caps help to smooth out the instantaneous demand spikes that can damage your alternator. Another option is to contact an alternator/starter repair shop to see if they can rewind your alternator for higher voltage and current output. If they can, be sure you DO NOT exceed 14.4 volts! Most mobile electronics can be damaged when run above 14.4 volts and the shop won't know that. The dimming lights described by others is typically caused two ways. The most common is a weak or damaged battery. When a standard battery with stock wiring is used in a high-demand application, it develops internal defects that keep it from charging or supplying fully. When this happens, the additional current required by the sound system is sacraficed by the other electronics in the vehicle and drawn directly from the alternator. The other typical cause of dimming lights is the vehicle's wiring. In other words, the factory power cables can't support the extra load of the sound system. All vehicle electrical systems are designed to provide the stock components with adequate power and have a little extra capacity to allow for extreme conditions. If you plan on doubling the current load, you need to build that capacity into your vehicle. Options one and two above should take you where you want to go. Remember to have your battery load tested every year as a precaution. | 
