If you look around the Internet, it won’t take long before you see someone say that hooking up an amplifier is as easy as connecting a few wires. Are they right? Well, yes. You most certainly do need to hook up some wires. You also need to know how to connect those wires, disassemble your vehicle, run the wires safely and reassemble the vehicle. Oh, did they mention that only covers the power wire? You still need a ground wire, signal cables, speaker wires and a remote wire. No problem, right? You can figure this stuff out, it’s just hooking up wires! You have access to YouTube, Facebook and your friend whose dad is an electrician.
Most people don’t have everything they need to set up an amp accurately. Do you have the equipment to test the audio signal you are feeding to the amp to ensure it doesn’t distort? Do you have the tools to ensure the amp can handle the signal input voltage you’ll be delivering? Do you know how to set the sensitivity control and the crossovers?
Suddenly, hooking up a few wires has blossomed into a full-on engineering project that requires a multimeter, an oscilloscope and a real-time analyzer. Let’s look at what it takes to install a simple five-channel amp in a new car. We think you’ll be surprised.
Step 1: Power Delivery
The task is simple: Provide your new amplifier with an appropriate connection to the vehicle electrical system. The connection requires adequately sized conductors for minimal voltage drop at the rated current requirements of the amplifier. If you’re on a budget, you will need to know how to de-rate the power wire if it’s not pure copper. The installation needs a protection device to guard against short circuits in the event of an accident or mishap with the amplifier. The ground return path needs to offer minimal resistance in order to prevent ground loops in the system.
To complete this task, you will need to find a path from the vehicle battery to the amplifier. The path must be away from any moving components or sources of heat. You’ll also need to avoid sources of electrical interference, if possible.
You will need to know how to identify vehicles constructed using aluminum, composites or laminated materials and how to compensate for this. You will need to recognize where vehicles are assembled using adhesives instead of spot welds and how to compensate for that.
Choosing a reliable and appropriate protection device is also crucial. You want something that can withstand exposure to the elements while maintaining adequate protection and minimal voltage loss. You need to know where and how to mount the device so that the vehicle is protected properly.
If you have to drill holes for anything, make sure you know how to check for factory wiring harnesses, fuel lines, brake lines and emission control components. You’ll need something to treat the metal after you have drilled it so that it won’t rust. You will need to protect the wires you run through the hole. If you have completed all the tests to confirm that you can use the chassis as your ground return path, the same precautions apply to drilling that hole. You need to prepare the vehicle for the ground connection, and have a plan to treat it after installation to prevent corrosion. Of course, you need the appropriate hardware to fasten the ground connection or connections properly, safely and securely.
Finally, you will need to have the proper tools to make your connection to the amplifier. These tools may be a simple as a sharp knife, or may include the need for a terminal crimping tool capable of handling appropriate-sized spade or ring terminals. Depending on the amplifier, you may need wire ferrules for a secure, efficient and reliable installation. You’ll also need a screwdriver and a set of Allen keys.
Step 2A: Signal Delivery – Aftermarket Radio
If you have chosen to replace the stock radio in your vehicle with an aftermarket unit, connecting the amp to the source unit is as simple running RCA interconnect cables. Isn’t it? First and foremost, you will need to know what length of cable you need. The cables certainly can’t be too short, and if they are too long, how will you deal with the extra length? The choice of cables is also quite important. Are the inputs to your amplifier single-ended or differential? If you don’t know, do you have the tools to test the amp? Based on the answer to the amplifier input stage design research, have you chosen the correct style of interconnect for your application? Your choices include twisted pair cables and coaxial cables, each of which have many options for shielding.
In terms of running the interconnect cables through your vehicle, do you know how to disassemble the vehicle adequately to run the cables safely and securely? If the cables are visible when you deem the installation complete, well, it isn’t. Do you know what devices and areas to avoid while running the cable? Do you have the supplies to secure the cables in place to prevent them from buzzing and rattling in the dash as you drive?
Step 2B: Factory-Installed Source Unit
If you will be using the factory source unit to feed your amplifier, you need to know what wires to hook up. If you are lucky, someone may have worked on a car like yours and hopefully wrote down which wire goes where. If nobody has provided the answers, you’ll need some tools to do some research.
First, you need to find the audio signal coming out of the factory source unit. In some cases, there is no analog audio signal present at the source, only out of the factory amplifier. Then you’ll need to determine the polarity of the signal. Next, you’ll need tools to determine the frequency response and amplitude of this signal. You will also need to be able to discern whether the signal is usable all the way up to full volume on the head unit. Finally, you’ll need to determine what kind of signal you are dealing with. Is it balanced or single-ended? Does the frequency response change with different volume settings? Does the signal contain the audio information you need, or is there an upmixer in the vehicle? Other tests include checking for phase equalization in the signal and the presence of warnings and alerts from the vehicle safety systems.
Depending on the answers you get, you will need to determine how to proceed. Can you connect the RCA interconnects directly to the speaker wire? Do you need a line-level converter? Do you need something to remove equalization and time alignment from the signal? Do you know how to deal with phase EQ? Hopefully you can get this right, or your upgrade may not sound very good.
Step 3: Running Speaker Wires
OK, now that we have done all of our testing and made sure we have a usable signal for our amp, it’s time to run wires to the speakers. If you are using the factory speakers, you can use the factory wiring to save some time. Just follow the rules about where and how to run speaker wires relative to noise sources, sharp edges, moving objects, heat sources and so on.
If you are running new speaker wire in the doors, you need to know how to take the trim off the door without damaging it or losing any of the clips. You will have to remove the door handle and lock release cables from the door panel. In some vehicles, the window regulator needs to come out so that you can access the inside of the wire boot.
Speaking of wire boots, most include a connector of some kind on the vehicle side, so you will need to know how to deal with those, and how to safely and securely add a quick-disconnect to the wire to make sure the door remains serviceable.
After you have the wire in the door, you will need to connect to the speakers. This could be as simple as crimping on spade terminals, using a terminal block or soldering to a factory wire plug. It’s always good to check the wiring to verify that you have the polarity correct before you put the door back together. Oh, and make sure you use appropriate wire management so that the new speaker wire doesn’t interfere with the window mechanism.
Step 4: Amplifier Configuration
Congratulations! If you have made it this far, then it’s clear sailing to the finish line. You will have determined that the audio signal you are connecting to the amplifier will work within its specifications for voltage and signal type (balanced or not). The next step is to configure the crossovers on the amplifier. In most cases, you will be applying a high-pass filter to the front and rear speakers and a low-pass filter to the subwoofer on the mono channel. We all know that the crossover frequency labels on amplifiers are notoriously inaccurate, so you may need an RTA to measure the frequency response of the system as you fine-tune the crossovers. You’ll need to know how low to set the crossovers so that you can establish a solid bass foundation in the front of the vehicle while protecting the speakers from excessive excursion. Next, you need to blend the subwoofer crossover with the front and rear speakers so that there are no gaps or significant overlaps in frequency response. If there are any phase issues with the midrange speakers blending with the subwoofer, you need to know how to compensate for that.
The last step is to set the sensitivity control on your amplifier to ensure that you have maximized the signal-to-noise ratio of your audio system and ensured that it will not distort significantly at full volume. It should also be noted that a lot of factory source units distort at full volume, so your tests in section 2B will determine what the new “full volume” setting on your deck is. Being able to distort the signal a little bit is OK, as it allows you to play music that was recorded quietly at enjoyable levels. It’s also necessary to know how much gain overlap is appropriate for the subwoofer and midrange speakers.
Step 5: Testing the Installation
Once the installation and configuration are complete, the system needs to be tested. The person doing the work will need a reference against which he or she can judge the performance of the upgrade. We aren’t quite sure what to tell you about this. You either have a reference for a great sounding audio system, or you don’t. If there is something wrong, the installer will need to resolve the issue. Potential problems include engine noise, heterodyne noise and radio reception issues from an installation standpoint. You also need to know how to check the system to verify that all the speakers are in correct polarity and the signals from each are summing at the listening position.
Congratulations on Your Amplifier Installation
Well, there you go. That’s a short list of things you need to know in order to install, test and troubleshoot the wiring up of your new amplifier. We didn’t talk about guidelines for amplifier mounting locations or mounting methods, since those topics vary a great deal based on amplifier choice, vehicle design and the chosen style of installation.
If you decide that you don’t have the tools to complete any one of these tasks, your local mobile enhancement retailer is willing to help you out with your installation. Give them a call!