There was a time when automobiles did not have a car audio system at all. These days, it is hard to find any type of automated vehicle that does not have some sort of sound system built in or attached. Car audio systems are very important to most auto owners and the types of systems available have a very wide range. There are also many components that can be used to complete your audio system such as amplifiers, head units, speakers and auxiliary input devices that work together to provide you with a complete system that fits your needs.
An amplifier allows you to increase signals that are processed through the amplifier to make them audible. Basically, amplifiers can take a weak audio signal and boost it to generate a signal strong enough to use speakers. The size of the amplifier needed will be based on the system you are putting together.
Speakers tend to be the main component that is in focus when building a car audio system. Keep in mind that in order for your speakers to perform that their best capacity that you must have other equipment to support so there able to reach it. Various styles will have advantages and disadvantages. Speakers themselves are what take a digital signal and convert them to actual audio. Placement of speakers can also greatly affect the sound quality that the vehicle occupants are able to enjoy.
The head unit is what controls what you actually hear. This includes volume, tuning, bass, treble, and any equalizer options. This is also commonly the device in which you will insert your tape, cd, or input any sort of digital audio.
It is important not to "skimp" on any of these devices when building an audio system if you expect to have a premium sounding system. If any of these components are not quality or do not meet the requirements of your system you will notice when it is complete and at that point it could be costly to reinstall and purchase new equipment.
Purchasing such components online can be a very good way to cut the cost of the equipment. Commonly, car audio purchased from retail locations carry a very large margin so be sure to compare the prices online to your local retailers to see the huge difference. As far as installation goes, make sure you are working with a person or company that you can trust will do a good job with your vehicle along with charging you a reasonable price.