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.