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Car Audio Buyers Guide


Monoprice offers a line of competition quality car audio components and accessories for your personal or business use. We have various components available which may make it a bit confusing when trying to piece together a system that is right for your listening preference, as well as what will fit your vehicle. This buyer's guide will provide information and technical specification for Monoprice car audio products and accessories for your vehicle. When installing a car audio system the most important part of the process is the planning phase. While performing the installation of any car audio system it is important to have a detailed plan and to have all of the necessary components and accessories available to ensure a smooth and timely installation and great sound quality.

Basic Components

The basic components to a car audio system are: head units, speakers, woofers, and amplifiers.

Head Units

The head unit is by far the most important part of your system whether it is just for your everyday listening or for that competition style system. The first thing you should ask yourself when putting together a system is "What do I need now and what do I have planned for the future?" If you are just planning on something basic like powering your existing factory speakers in your vehicle then a simple 4 channel stereo with a built in amplifier should be enough for you, but if you are planning to expand now or in the future then a bit more thought needs to be put into the selection of your head unit. Ask yourself the following questions:

  1. Am I going to be using my iPod or MP3 player with my stereo?
  2. Am I going to be upgrading my speakers in the future?
  3. Do I want to add an amplifier to my new speakers?
  4. Do I want to add a subwoofer later?

If you answered yes to any of the above questions then we need to consider a few things. If you will be adding an iPod or MP3 player you should consider looking into a head unit with a dedicated iPod input or a 3.5mm Auxiliary jack for most MP3 players. This will allow you to play your device through your head unit. If you will be upgrading your speakers or adding an amplifier you should consider looking into a head unit with RCA preouts. The RCA preouts will allow you to send an audio signal from your head unit to your amplifier via RCA cables which will power your speakers to give you a much clearer sound. Head units will come with anywhere from 1 to 3 sets of preouts (Front, Rear, and Sub Preouts). If you will be adding a subwoofer to your vehicle then you should consider looking into a head unit with a dedicated subwoofer preout. The subwoofer preout will allow you to independently control your subwoofer without affecting the other speakers. It allows you to control the level and with some head units you can even control the frequency of the subwoofer.


Replacing the factory speakers in your vehicle can give you a wide range of sound that you can never achieve with a set of factory speakers. When selecting a speaker it is very important to know what will fit your vehicle. There is a wide variety of speakers available from a very small 3 1/2" round speaker all the way up to a 6" x 9" oval speaker. There is no universal speaker for all vehicles and although it can be done, it is not recommended you modify the size speaker your vehicle will accommodate. Depth is another important factor to take into account when selecting a speaker, especially if it will be installed in a door where the speaker may be in the path of a window when rolled down. Make sure you roll down your window and measure the depth you have between the inside door skin and the window before selecting a speaker.


A woofer can add a great deal to the overall sound of your system when done the right way. When selecting a woofer it is very important to keep in mind the impedance of the woofer. The most common mistake is connecting a woofer or woofers to an amplifier and creating too low of an impedance. If you do this there are a few things that can go wrong from as simple as the amp going into protection mode and shutting off to the amp overheating and "burning out" or "blowing". Always make sure to match the impedance to the amp and never go under the rated minimum impedance.


Monoprice amps come in 3 different varieties, 4 channel, 2 channel, and mono block. The number of channels typically refers to the number of speakers it is meant to drive. An amp is typically rated by how much wattage it can produce per channel at 2 or 4 ohms. An example would be 200 watts x 4 @ 4 ohms or 400 watts x 4 @ 2 ohms. It is very important to either match or be above the rated impedance in order to not damage the amplifier. It is also very important to use the correct gauge power wire. The following table will show the proper gauge to use for the power your amplifier produces and the length of the run. It also shows the proper size fuse that should be used for the amount of current you will be drawing. To calculate the proper power and ground cable sizes, find the distance of the power cable along the top row. If your measurement is between two measurements, use the higher one. Next, find the total RMS power the cable must support on the left. If your measurement is between two measurements, use the higher one. The size listed where your two measurements meet is the recommended cable size. Ground cables should be the same size (or larger) as the power cable. Although wire gauge sizes smaller than 10 gauge may be acceptable for the amount of current draw, we recommend using 10 gauge as the smallest wire size for any amplifier of 100 watts or more. The goal is to provide as much current to the amplifier as it could possibly need for optimal performance.

Recommended Cable Size by Power and Distance
Total RMS
Power (watts)
4 feet8 feet12 feet16 feet20 feet
10010 gauge10 gauge8 gauge8 gauge4 gauge
20010 gauge8gauge8 gauge4 gauge4 gauge
4008 gauge8 gauge4 gauge4 gauge4 gauge
6008 gauge4 gauge4 gauge4 gauge4 gauge
8004 gauge4 gauge4 gauge2 gauge2 gauge
10004 gauge4 gauge2 gauge2 gauge2 gauge
14004 gauge2 gauge2 gauge2 gauge2 gauge
Current Draw by Power
Total RMS Power (watts) Current Amps
Power & Ground Cable Specs
Cable Size Wire GaugeCurrent Capacity Amperage (amps)
12 40
14 25

Now that you have your head unit, speakers, woofers, and amplifiers picked out and planned, you're ready to begin building your car audio system. Keep in mind that even a small basic car audio system can easily turn into a lengthy project and there may be hurdles along the way. As long as you have a solid plan and have done your research before beginning the project everything should turn out just fine and you'll soon be enjoying the great sound from your Monoprice car audio system! If you have any questions or need guidance along the way, please feel free to contact Monoprice technical support via LiveChat or by email at Tech@monoprice.com at any time and our friendly technical support staff will be glad to assist you.

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