MS81: How To Set Up, Install & Use

Introduction

The Rockville MS81 ceiling speakers are designed for commercial spaces such as restaurants, offices, gymnasiums, and more. These 70V PA speakers allow you to connect multiple units to a single amplifier while maintaining consistent volume and power distribution.

This guide will cover:
✅ How 70V sound systems work
✅ Wiring and tapping speakers for optimal power distribution
✅ Ceiling installation and connecting to an amplifier

Understanding 70V Systems

A 70V amplifier allows you to run multiple speakers at a fixed wattage from a single amp. This setup is ideal for commercial spaces where you need uniform sound coverage.

• You can run 100+ speakers from one amp if the total wattage of all speakers does not exceed the amp’s output capacity.
• Each speaker has a tap setting that lets you control its wattage draw.

Example Power Calculation

• If your amp has 100W, you can set:
  • 20 speakers to 5W each
  • 10 speakers to 10W each
  • 5 speakers to 20W each

For multi-zone amps:

• Each zone has an independent wattage limit.
• Match the tapped wattage of speakers to the amp’s zone rating.
• Adjust volume individually per zone.

For more details on 70V technology, check out Rockville University’s 70V video guide.

Step 1: Wiring the Speakers

1. Selecting the Correct Tap Setting

The MS81 speakers have multiple tap settings for different power levels.

• To wire in 70V mode:
  • Use the colored wires on the back to select the desired wattage tap.
  • Example: For 10 speakers on a 50W amp, use the 5W tap (blue wire).
  • Connect the positive speaker wire to the selected tap wire.
  • Connect the negative speaker wire to the black (common) wire.
• To wire in 8-ohm mode (home theater use):
  • Disconnect the black and white wires from the 8-ohm bypass harness.
  • Replace them with standard speaker wires running to your home receiver.

2. Running Wires in Parallel (Daisy-Chaining Speakers)

• When running multiple speakers, connect them in parallel:
  • Connect the positive terminal of one speaker to the positive terminal of the next.
  • Connect the negative terminal of one speaker to the negative terminal of the next.
• Important: Cover any unused wires with electrical tape to prevent short circuits or electrical hazards.

Step 2: Installing the Speaker in a Ceiling Tile

1. Cutting the Speaker Hole

1. Use the included paper cutout template to mark the speaker cutout on the ceiling tile.
2. Cut out the hole using a blade or utility knife.

2. Mounting the Speaker

• For Drop Ceilings (Tiles)
  • Insert the speaker into the cut hole.
  • Use the included bolts to attach it to the ceiling tile.
  • Secure the back of the bolts with nuts.
• For Solid Ceilings (Drywall, Sheetrock, etc.)
  • Use the included screws and anchors for installation.

Step 3: Connecting to the Amplifier

1. Running Speaker Wires to the Amp

• Route the speaker wires from the ceiling down to the amp.
• Connect them to the 70V output terminals on your amplifier.
• If using a multi-zone amp, connect the wires to the correct zone output.

2. Adjusting Volume

• Use the amp’s master volume to control overall speaker output.
• Each MS81 speaker has an independent volume dial on the front grille for fine adjustments.

Final Thoughts

The Rockville MS81 8-inch 70V PA ceiling speakers are easy to install and offer excellent sound distribution for commercial spaces. By properly wiring, tapping, and mounting the speakers, you can create a scalable audio system that delivers consistent and high-quality sound.