This reading is going to contain the basics for installing everything from power upgrades to how to install door speakers. I will touch on power upgrades under the hood, amplifier installation, speaker installation, head unit installation, and sub woofer installation.
The first thing I would recommend to anyone buying audio equipment would be to talk to someone that knows what they are talking about and then purchase online! I say this because audio equipment tends to be grossly overpriced and typically most audio shops will not have exactly everything you need. The system in my car was purchased online down to the ring terminals I used. Also for audio installation there are plenty of videos on YouTube that are of great use during beginner installation. All of that being said talk to someone who knows what they are talking about, come up with a budget, determine what you want out of your system (loud, high quality, etc.), and finally purchase the necessary components on the internet.
Amplifiers draw a lot of power from a cars battery so the first thing that should be done is to “beef up” the electrical system in your car. In varies in the degree of application, very high powered amps will require a second battery and multiple amps could require a second battery, but it can also be as simple as something like the big 3. The big 3 is a basic way to improve the flow of electricity from the alternator to the battery to the ground. For this you will need some good wire I use 0 gauge wire and some ring terminals, I recommend spending the extra dollar for the good ring terminals. Lastly, you could include a fuse, but it is not necessary. Get your wires all to the right length appropriately attach the ring terminals. Now you’re ready to add these three wires the first wire goes between the alternators positive and the positive post on the battery. The second wire goes from the ground on the engine to the negative post on your battery. The last wire goes from any bare metal place you can find in the engine bay to the negative post on your battery. Once you have installed these three wires the electrical system in your car is ready for a rather powerful system.
The next thing to do is install the head unit. This part varies a lot from car to car. Newer cars may require professional installation depending on how much is integrated into the stereo component of your car. For older cars it tends to be as easy as buying an installation kit popping the old one out and popping the new one in, this is where speaking with a professional comes into play. A professional would be able to tell you these things.
After your electrical system is beefed up and your head unit is installed next is the amplifiers and capacitors. In my setup I used two amps. So that is what I will explain the installation of. One amp is for the sub woofers only and the other amp is for the speakers in the car. There are three wires in your car that have to go from your amp all the way to the front of your car. This is the hardest part of the installation because it requires drilling a hole through the fire wall, installing a fuse in your car and feeding the wire to the trunk (where most amps are placed in cars). The other two wires are the remote wire, which tells the amp when to turn on and off and the RCA cables which are the actual audio cables. That all being said when you’re done there should be RCA cables, remote wire, and power wire (positive) in the trunk. This is when you would want to find a bare metal place in the trunk and attach a ground wire, preferably the same gauge as the power wire. After you have your ground and your positive wires then you need to add your splitters which will split your ground and your positive wires into two wires. So now in the trunk you should have a power wire with a splitter splitting into two power wires, a ground wire on bare metal with a splitter splitting it into two ground wires, RCA cables, and a remote wire. This is when you would add the capacitor to the power wire you’re going to use for the sub woofer amp. The capacitors main job is to keep the flow of electricity to the amp constant, so if there is a drop in voltage the capacitor will release some energy. Now finally the installation of the amps is possible. I recommend finding somewhere to fasten the amps in the trunk as opposed to letting them slide around. This is when you connect the power wire to the positive connection on both amps. The ground wire to the negative connection on the amp. The RCA cables to the red/white/left/right ports on the amp. Lastly connect the remote wire to the remote port on the amps. During all of these connections the fuse on the power wire should be tripped to avoid being shocked. Once you’ve connected both amps turn the fuse on turn the head unit on and make sure the amps fire up with it.