A stereo is the main component of any car audio system. It is often called the radio, receiver, or head unit. To understand how a stereo functions, it's helpful to think of a car in-dash stereo as having three different parts: source, preamp, and amplifier.
The source is the part that lets us choose what we want to hear. Sources may include a standard AM/FM tuner, CD or DVD player, satellite radio, iPod® or smartphone, or a USB input. The Preamp is where all sound adjustments are made. A preamp includes controls ranging from simple volume, balance, fader, source selection, and tone adjustments to sophisticated crossovers, equalizers, and time correction. The amplifier section boosts the small (low-voltage) audio signal coming from the preamp section into a larger (high-voltage) audio signal that's sent out to the speakers.
So, why should you replace or upgrade your stereo?
Many people have opted to upgrade their stereo because of the advanced technology modern receivers offer. Some of these advanced source features include: full-color animated displays, smartphone integration for Apple and Android, Bluetooth, Satellite and HD Radio, GPS Navigation, customizable color schemes, touchscreen monitors, precision sound controls and parametric equalization. Aftermarket car stereos can enhance the appearance of your car's interior with their sleek design.
A new stereo will also give the amplifier need to achieve a louder sound. Not only is it significantly louder than, but with the built-in power and more advanced circuits it also produces cleaner, richer, more detailed sound. Enhanced tone controls in the preamp section mean that you have more control over fine-tuning the music.
After market stereos also offer expandability with auxiliary inputs, USB connections, and audio/video outputs let you expand your system by connecting portable music players, rear seat video screens, external amplifiers, and powered subwoofers.
Aftermarket stereos also have security features like detachable face plates and security codes to help protect your investment from theft.