RXC4D: How To Set Up, Wire & Install

Introduction

If your headlights dim or your wipers slow down every time your bass hits, your car’s electrical system is struggling to keep up with the demands of your amplifier. A stiffening capacitor solves this problem by storing and releasing electrical current instantly when your system needs extra power.

In this guide, we’ll show you how to install the Rockville RXC4D capacitor to improve your car audio performance. The steps are simple and can be followed even if you don’t have advanced technical knowledge.

Requirements:

• Rockville RXC4D Capacitor (2 Farads, works with 12V systems and up to 24V surge)
• Basic car audio amplifier setup
• Power and ground wire (8 or 4 gauge recommended)
• Wire crimper/stripper

Step-by-Step Instructions

1. Understand What a Capacitor Does

• Think of the capacitor as a fast-acting power storage tank.
• Unlike a battery, it can charge and discharge in nanoseconds, delivering instant power to your amplifier.
• This helps keep bass tight and eliminates issues like dimming headlights.

2. Check Included Accessories

Your Rockville RXC4D package includes:

• Hex wrench (for tightening terminals)
• Four stainless steel screws (for the Lucite bracket mount)
• Two ring terminals (positive and ground connections)
• Bleed resistor (for safe first-time charging)

3. First-Time Charging (Important Safety Step)

• Before regular use, connect the bleed resistor in series with the positive terminal of the capacitor.
• This slows the charging process, preventing damage.
• Wait about 10 seconds for the capacitor to safely reach charge.

4. Prepare the Wires

• Use 8 or 4 gauge wire for best performance.
• Attach the black ring terminal with the rubber jacket to your ground wire.
• Attach the red ring terminal to your positive wire.

5. Connect the Capacitor

1. Use the hex wrench to open the capacitor’s terminals.
2. Connect the positive (red) ring terminal to the positive post.
3. Connect the negative (black) ring terminal to the negative post.
4. Run the positive wire from the capacitor to your amplifier’s positive terminal.
5. Ensure the capacitor is also powered from your car battery or a distribution block.
6. Run the negative wire from the capacitor to a solid ground point in the vehicle.

6. Power On and Verify

• Turn on your car audio system.
• The voltage display on the RXC4D will begin climbing, showing your car’s system voltage.
• Blue LEDs will light up like a power meter as voltage changes.

Choosing the Right Capacitor Size

• RXC4D (2 Farads): Ideal for systems up to 1000 watts.
• RXC 4D (4 Farads): Recommended for systems over 1000 watts.

Troubleshooting & FAQs

Q: My headlights are still dimming—what should I do?

• Check your ground connection to ensure it’s secure.
• Make sure you’re using at least 8-gauge wire.
• If your system is over 1000 watts, consider upgrading to the RXC 4D capacitor.

Q: Do I still need the resistor after the first charge?

• No, the resistor is only used the first time to safely charge the capacitor.

Q: Can I install the capacitor anywhere in my car?

• Mount it close to your amplifier for best performance.

Conclusion

Installing a stiffening capacitor like the Rockville RXC4D helps eliminate power dips, improves bass response, and protects your car’s electrical system. With just a few wiring steps, you can achieve clearer sound and say goodbye to dimming lights during heavy bass hits.