How Much Is A Sub On Kick

Alright, let's talk about the often-misunderstood beast that is wiring up a subwoofer to your car's audio system. Specifically, we're diving into how much of a load a sub places on your kick panel speaker wires if you're considering (or already have) tapped into them. This isn't for the faint of heart, and you absolutely need to understand the implications before even thinking about clipping those wires. This article will give you a solid understanding of what's going on behind the scenes.

Why This Matters: Preventing Electrical Nightmares

Why is understanding this critical? Because incorrectly wiring a subwoofer to your existing speaker wires can lead to a cascade of problems, ranging from poor audio quality to permanent damage to your head unit, amplifier (if you have one for the speakers), and even the wiring harness itself. The goal here isn't just to get bass; it's to get bass safely and effectively. We're talking about preventing blown fuses, overheating wires, and potentially even a fire. Learning how much of a load your sub places on a circuit helps you choose the right setup and components. It also empowers you to troubleshoot issues effectively.

Key Specs and Main Parts: Deciphering the Jargon

Before we dive into the wiring, let's define some key terms:

Impedance (Ohms, Ω): This is the resistance to the flow of electrical current in a circuit. Subwoofers are typically rated at 2, 4, or 8 ohms. Your factory speakers usually fall in the 4-8 ohm range. Mixing impedance improperly can fry components.
RMS Power (Watts): This is the continuous power a speaker or amplifier can handle or deliver. Think of it as the "real" power, not the peak (which is often inflated).
Head Unit: Your car's stereo. It outputs a signal that drives the speakers.
Amplifier: A device that boosts the signal from the head unit to power the speakers (including the subwoofer). Most factory head units have a built-in amplifier, but it's often relatively weak.
Parallel Wiring: A wiring configuration where multiple speakers are connected side-by-side, reducing the overall impedance seen by the amplifier. This can increase power output but also increase the current draw.
Series Wiring: A wiring configuration where multiple speakers are connected end-to-end, increasing the overall impedance. This decreases power output but reduces current draw.

The main components involved are:

Head Unit (or Factory Amplifier): The source of the audio signal.
Kick Panel Speakers: The front speakers in your car, often located in the kick panels near your feet.
Subwoofer: The speaker specifically designed for low-frequency sounds (bass).
Wiring: The wires connecting everything together. Use appropriate gauge (thickness) wiring for the power and ground.
Line Output Converter (LOC): If you're using a factory head unit without RCA outputs, you'll likely need an LOC to convert the speaker-level signal to a lower-level signal that can be used by an amplifier.

Understanding the Diagrams: A Visual Guide

A typical wiring diagram for adding a subwoofer tapped into the kick panel speakers (using a line output converter) would show the following:

Solid Lines: Represent wires. The thickness of the line *might* indicate the gauge of the wire.
Dotted Lines: Often represent signal paths or shielded wires.
Rectangles: Head unit, amplifier, or LOC.
Circles: Speakers (kick panel and subwoofer).
Ground Symbol (usually a triangle pointing downwards): Indicates a connection to the vehicle's chassis, which serves as the ground for the electrical system.
"+" and "-": Indicate positive and negative terminals. Getting these reversed can damage equipment.

Colors are also crucial. While not always standardized, common conventions include:

Red: Positive (+) power wire.
Black: Ground (-) wire.
Blue/Green/White/Gray: Speaker wires. Often twisted pairs.
Yellow: Constant 12V power (for memory retention in the head unit).
Orange: Switched 12V power (turns on with the ignition).

When you download the wiring diagram (link at the end!), pay close attention to these symbols and colors to ensure you're making the correct connections.

How It Works: The Electrical Flow

Here's the basic flow of electricity and audio signal in this setup:

The head unit generates an audio signal.
This signal travels through the speaker wires to the kick panel speakers.
You tap into these speaker wires using a Line Output Converter (LOC). The LOC takes the speaker-level signal and converts it to a lower-level RCA signal.
The RCA signal is then fed into an external amplifier (specifically for the subwoofer).
The amplifier boosts the signal and sends it to the subwoofer, producing bass.

The critical factor here is the impedance. Adding a subwoofer in parallel with your existing kick panel speakers lowers the overall impedance seen by the head unit's amplifier (or the factory amplifier). This is where things can get dangerous. If the resulting impedance is too low (e.g., below 2 ohms), the amplifier may overheat and shut down, or even be permanently damaged. Many factory head units are not designed to drive low impedance loads.

Calculating the total impedance of speakers in parallel is not straightforward. If you have two 4-ohm speakers in parallel, the total impedance is 2 ohms. If you have a 4-ohm kick panel speaker and then tap into it to wire in a 4-ohm subwoofer, the combined load could potentially damage the factory head unit. The exact amount of "load" depends on the power of the subwoofer and the design of the amplifier.

Real-World Use: Troubleshooting and Best Practices

Here are some common problems and how to troubleshoot them:

No Sound from Subwoofer: Check all wiring connections, fuses (on the amplifier and head unit), and the LOC. Ensure the amplifier is powered on and that the gain is properly adjusted.
Distorted Sound from Subwoofer: Check the gain settings on the amplifier. If the gain is too high, it can cause clipping (distortion). Also, make sure the subwoofer is not being overdriven (receiving more power than it's rated for).
Head Unit Shutting Down/Overheating: This is a sign that the impedance is too low and the amplifier in the head unit is being overloaded. Disconnect the subwoofer immediately. You *might* need to use a separate amplifier for both your kick panels and subwoofer.
Weak Bass: Check the phase of the subwoofer. If it's out of phase with the front speakers, it can cancel out some of the bass frequencies. Try reversing the polarity of the subwoofer wires (+ and -) to see if it improves.

Best Practices:

Use a dedicated amplifier for the subwoofer. This is the safest and most effective way to add a subwoofer to your car. A dedicated amp is designed to handle the lower impedance load of a subwoofer.
Use a Line Output Converter (LOC) if you're keeping the factory head unit.
Use proper gauge wiring. Don't skimp on the wiring. Use thicker gauge wire for power and ground connections, especially for the amplifier.
Properly ground the amplifier. A good ground connection is essential for proper amplifier performance.
Set the gain correctly. Use an oscilloscope or a digital multimeter (DMM) to properly set the gain on the amplifier. There are many resources online with step by step instructions.

Safety First: Respect the Electricity

Working with car electrical systems can be dangerous. Always disconnect the negative terminal of the battery before starting any electrical work. This will prevent short circuits and potential damage to your car's electrical system. Be extremely careful when working around the airbag system. Accidental deployment of an airbag can cause serious injury. Avoid probing or cutting into any wiring harnesses that are near airbag components. The amplifier and wiring can get very hot, especially if the load is too low. Avoid touching these components while the system is in operation. Keep wires neatly organized and secured to prevent them from rubbing against sharp edges or getting caught in moving parts.

The most risky component in this setup is the factory amplifier (either in the head unit or a separate unit). Overloading it can cause permanent damage. Always err on the side of caution and use a dedicated amplifier for the subwoofer. If you are going to try wiring a sub to the kick panel wires, then you need to be able to measure the voltage and resistance of the wires. Also verify the output and power ratings of the factory amplifier.

By understanding the electrical principles and following these safety guidelines, you can safely and effectively add a subwoofer to your car's audio system. Remember, if you're unsure about anything, consult a professional car audio installer.

We have the detailed wiring diagram referenced in this article available for download. It includes specific wire colors and connection points for common car models. You can [link to download].