If you are considering upgrading your car’s sound system, your first step will most likely be to replace the factory head unit with an aftermarket product. As long as you already have working speakers, this move can instantly improve the sound. There are several names for this system component, and one is “head unit,” which applies to any dash-mounted interface that controls car audio.

Varieties of main units

Tuner – A unit that lacks built-in power amplification. Tuners require an additional amplifier to power the speakers.

Receiver: one that contains a built-in amplifier. A receiver can be used to power an existing set of speakers without other equipment.

Controller – An interface that does not have a radio function, although it can include any combination of CD, DVD, cassette, auxiliary inputs, and / or USB.

Mechless – A receiver or tuner with no CD, DVD, or cassette capability. “Mechless” refers to the absence of mechanical (moving) components, as these devices feature solid state construction. These devices may also have AUX, USB, and Bluetooth® compatibility.

Some of these categories overlap. For example, mechless drivers and heads can exist with or without built-in amplifiers. You will need to read the specifications of any equipment you are interested in to make sure it meets your requirements.

What do you need?

Now that you know the basic distinctions, you need to consider the factors that may influence your decision on which car audio equipment to install. If you just want to replace what’s on the dash first, you’ll need something with its own power to get the sound out of your factory speakers. However, if you plan to upgrade your speakers and add subwoofers and tweeters for a total overhaul of your car’s audio system, you will likely need an external amplifier to provide enough power. In this situation, you may want to buy a receiver with preamp outputs. These outputs will bypass the built-in power, resulting in less distortion so you can play louder music without sacrificing sound quality. If sound quality is your focus and volume isn’t important, you can save money by forgoing the amp and subwoofers, using a unit with enough power, and buying better quality door speakers.

Now think about getting into your car and being in the mood to listen to your favorite songs. What would you achieve? Have a vast CD collection that you would like to swipe and listen to from start to finish? If so, you definitely need a model with a record player. Maybe you’ve ditched hard copies and your music is stored digitally on your smartphone or dedicated audio player. In this case, you can choose not to use any mechanisms and play your library through a USB connection for the best audio. If streaming services on your phone are your preferred method of music retrieval, a dedicated Bluetooth interface is helpful or, at the very least, there should be an auxiliary jack.

With what you now know about the brain of your car audio system, you can prioritize the functions that are most important to you and look for a product that offers them all within your budget.