CT8-SUB: How To Set Up, Wire & Install

Introduction

The Rockville CT8 is an 8-inch 70V/100V commercial subwoofer designed to bring powerful low-end sound to conference rooms, restaurants, retail spaces, or even your home. This guide walks you through its setup and features in a simple, step-by-step way—no technical expertise required.

The CT8 subwoofer can be used in:

• 70V or 100V systems (with multiple speakers)
• 4-ohm bypass mode for standard speaker setups

All you’ll need is a compatible amplifier (such as the Rockville RCS series) and speaker wire or banana connectors.

Step-by-Step Instructions

1. Understand the Power Options

The CT8 has a built-in transformer with selectable power taps for 70V/100V operation:

• 10 watts
• 20 watts
• 40 watts

If you bypass the transformer, the subwoofer operates at 4 ohms with 80 watts RMS handling.

2. Plan Your Wiring

• In a 70V/100V system, wiring is done in parallel:
  • Connect positive to positive and negative to negative across all speakers in the chain.
• You can also mix and match different speakers (wall, ceiling, and subs) in the same 70V system.

Important: Make sure your amplifier has enough total wattage to cover all speakers.

• Example: Ten 10-watt speakers require an amplifier rated for at least 100 watts.

3. Connect the CT8 Subwoofer

• Use the binding posts on the back of the subwoofer.
• Options for connection:
  • Bare wire (strip speaker wire and insert into the posts).
  • Banana connectors for a faster, cleaner connection.

4. Place the Subwoofer

• The CT8 is a floor-standing subwoofer.
• It features a down-firing driver and ported design, providing deep, tight bass when placed directly on the floor.

5. Configure Your Amplifier

If using a Rockville 70V amplifier such as the RCS350-6:

• Assign the subwoofer to its own zone for independent volume control.
• Other speakers (like ceiling speakers) can go to a separate zone.
• This allows you to fine-tune the balance between subwoofer bass and speaker clarity.

Troubleshooting & FAQs

Q: Can I use the CT8 in a regular home stereo system?
A: Yes, just bypass the transformer and run it at 4 ohms, 80W with a standard amplifier.

Q: How do I choose between 10W, 20W, or 40W taps?
A: Match the wattage to your room size and system needs:

• 10W = background bass for small rooms.
• 20W = medium-sized spaces.
• 40W = larger rooms or when you want stronger bass presence.

Q: Can I mix this subwoofer with ceiling or wall speakers?
A: Yes, one of the advantages of 70V systems is mixing different types of speakers on the same line.

Conclusion

The Rockville CT8 subwoofer is simple to set up and delivers rich, powerful bass for commercial and home spaces. By choosing the correct wattage tap, wiring in parallel, and pairing it with a capable amplifier, you’ll enjoy a balanced audio system with strong low-end support.