CT80-SUB: How To Set Up, Wire & Install

Introduction

The Rockville CT-80 is an 8-inch 70-volt commercial subwoofer designed to enhance the low-end frequencies in restaurants, conference rooms, and other commercial spaces. It can be mounted on a wall or placed on the floor, making it a versatile addition to any 70-volt sound system.

This guide will cover:

• Understanding 70-volt systems
• Connecting the subwoofer to a 70-volt amplifier
• Parallel wiring with multiple speakers
• Mounting the subwoofer to a wall

Step 1: Understanding 70-Volt Systems

A 70-volt amplifier allows multiple speakers to be connected and powered from a single amp at a fixed and constant wattage. This setup is ideal for large installations because it:

• Supports over 100 speakers from a single amplifier.
• Allows independent volume control for different speaker zones.
• Ensures consistent audio levels across all speakers.

Example Power Distribution

• A 100W amplifier can run 20 speakers at 5W each.
• Tapping speakers at specific wattage levels ensures the system stays within the amplifier’s power range.

Step 2: Understanding Wattage Tap Settings

On the back of the subwoofer, you’ll find wattage tap options for both 70V and 100V systems:

• For 70V amps: Set the subwoofer at 10W, 20W, or 40W.
• For 100V amps: Set it at 15W, 25W, or 55W.
• For 4-ohm amplifiers: Set the switch to 4-ohm mode.

Choosing the right wattage depends on your amp’s power output and the number of speakers in your system.

Step 3: Connecting the Subwoofer to a 70-Volt Amplifier

Single Subwoofer Connection

1. Take a speaker wire and connect:
   • Positive wire → 70V terminal on the sub.
   • Negative wire → Common (COM) terminal on the sub.
2. Connect the other end of the wire to an available zone output on your amplifier:
   • Positive wire → Positive terminal of the amp zone.
   • Negative wire → Negative terminal of the amp zone.
3. Tighten the terminals using a screwdriver.
4. Set the wattage tap on the subwoofer to match the amp’s zone power level.
5. Power on the system and test the sound.

Independent Zone Volume Control

Each zone on a multi-zone amplifier allows separate volume adjustments, so you can balance the subwoofer volume relative to the main speakers.

Step 4: Connecting Multiple Speakers in Parallel

Parallel wiring (daisy chaining) allows multiple speakers and subwoofers to be connected to the same amplifier output.

Parallel Wiring Steps

1. Connect the subwoofer to the first speaker:
   • Positive wire → Positive terminal on the sub.
   • Negative wire → Negative terminal on the sub.
2. Run another speaker wire from the subwoofer to the next speaker:
   • Positive wire → Positive terminal on the speaker.
   • Negative wire → Negative terminal on the speaker.
3. Repeat the process for additional speakers.
4. Connect the final speaker to the amplifier’s zone output.

Advantages of Parallel Wiring

• Expands the system to multiple speakers.
• Simplifies installation by running one cable per speaker.
• Allows balanced sound distribution across a large space.

Step 5: Wall Mounting the Subwoofer

The CT-80 includes mounting hardware for wall installation.

Mounting Steps

1. Choose a mounting location on a stud or sheetrock wall.
2. Mark the holes using the swivel mount plate as a template.
3. Drill pilot holes where you marked.
   • If mounting on studs, screw directly into the wood.
   • If mounting on sheetrock, use wall anchors for support.
4. Assemble the swivel bracket:
   • Slide the bracket base into the swivel mount.
   • Secure with bolts, washers, and nuts.
   • Use a wrench and pliers to tighten.
5. Attach the bracket to the subwoofer:
   • Loosen the four screws on the back of the sub.
   • Align the bracket with the screw holes.
   • Secure by tightening the screws.
6. Secure the mounting plate to the wall using screws or anchors.
7. Attach the subwoofer bracket to the wall mount and adjust the angle before tightening.
8. Run speaker wires through the ceiling or wall for a clean look.

Step 6: Testing the System

1. Play music through the system.
2. Adjust the subwoofer volume using the amplifier’s zone controls.
3. Check bass response and tweak the wattage tap settings for best performance.
4. Ensure a balanced mix with main speakers and the subwoofer.

Conclusion

The Rockville CT-80 8-inch 70V commercial subwoofer is a powerful addition to any 70V or 100V audio system, providing enhanced low-end frequencies for restaurants, conference rooms, and commercial spaces. Whether placed on the floor or wall-mounted, it integrates seamlessly into multi-speaker setups and can be customized for different zones.