The most significant component of a car audio system is the car stereo (also known as a head unit or in-dash receiver). It's an important part of any good sound system. Pre-amp outputs on head units allow you to connect amplifiers to boost the sound of your system. Amplifiers for automobiles The sound quality will be substantially improved if you use an amplifier to power your speakers or subwoofer. The audio signal from the vehicle's receiver is first received by an amplifier. The signal is then amplified to the proper wattage for the speakers or subwoofer.Here is a page that you can explore from Pioneer. Pioneer offers the best car audio and video system accessories stereo, radio, speakers, analog and digital amplifiers,sub-woofers, receivers, etc.