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MS81 Owner's Manual

Zohaib
Updated

8˝ 70V/25V Commercial In-Ceiling Metal Speakers

The Rockville MS81 is a great choice for any restaurant, office, school, retail store, or other commercial application. This speaker will sound great for all your PA announcements and background music. This in-ceiling speaker features a metal housing which is strong and long-lasting as well as a volume knob on the front that allows you to instantly tweak the volume without needing to remove the speaker!

Choosing the Appropriate Tap

The “taps” are the six color coded wires that extend from the transformer attached to the speaker. The first one is black and is the COM (negative) terminal. The other five are the available power options (see diagram below). These power options allow for full customization of the sound for the space in which the speakers are to be installed. In a restaurant, for example, you can tap your dining room, hallway and bathroom speakers at 2.5 watts. Then the speakers in the outside seating area can be set at 5 watts. Another feature of 70-volt speakers is that you can mix and match any type whether they are in-ceiling speakers (such as these), wall mounted speakers, subwoofers, etc.

Wiring diagram and color-code chart labeled "25V" in the top-left corner, detailing wire color assignments for a 25V speaker system configuration: * **Negative Wire:** * **BLACK COM:** Connects **TO THE NEGATIVE TERMINAL**. * **Positive Wattage Tap Wires (Connect TO THE 70V TERMINAL):** * **RED 5W:** 5 Watt power tap. * **YELLOW 2.5W:** 2.5 Watt power tap. * **GREEN 1W:** 1 Watt power tap. * **BLUE 0.5W:** 0.5 Watt power tap. * **BROWN 0.25W*:** 0.25 Watt power tap.

Attention: The Brown tap cable serves as the 0.25W tap when used in 25V mode and as the 2.5W tap when used in 70V mode.

Wiring diagram and color-code chart labeled "70V" in the top-left corner, detailing wire color assignments for a 70V speaker system configuration: * **Negative Wire:** * **BLACK COM:** Connects **TO THE NEGATIVE TERMINAL**. * **Positive Wattage Tap Wires (Connect TO THE 70V TERMINAL):** * **BLUE 5W*:** 5 Watt power tap. * **BROWN 2.5W:** 2.5 Watt power tap. * **VIOLET 1W:** 1 Watt power tap. * **ORANGE 0.5W:** 0.5 Watt power tap. * **GREY 0.25W:** 0.25 Watt power tap. 

Attention: The Blue tap cable serves as the 5W tap when used in 70V mode and as the 0.5W tap when used in 25V mode.

Wiring

70-volt speaker set-ups allow you to run very long lines of speaker wire without signal loss. Wire all the positive terminals of the speakers to the positive 70-volt terminal of the amplifier. The COM (negative) terminal on the speaker simply gets wired to the negative terminals on the amp. You don’t have to worry about impedance, as the power is constant. The total number of speakers multiplied by the tap value cannot exceed the output power (in watts) of your 70V amplifier. The example below shows 10 total speakers. Using the 70V 5W taps, the total wattage is 50W (10 speakers x 5W = 50W). A good rule of thumb is to select an amplifier with 15 to 20% greater power; in this case, an amplifier that delivers about 60W.

Multi-Speaker Connection

System wiring diagram illustrating a 70V commercial speaker installation connected in parallel to an amplifier's screw-terminal strip: * **Amplifier Connections (Bottom Left):** * A screw-terminal barrier strip displays terminals labeled **COM**, **4Ω**, **8Ω**, **16Ω**, **COM**, **25V**, and **70V**. * A wire runs from the second **COM** terminal to the negative (-) bus wire connecting all speakers. * A wire runs from the **70V** terminal to the positive (+) bus wire connecting all speakers. * **Speaker Array (Parallel Daisy Chain):** * Ten rectangular drop-in ceiling speaker tiles are lined up horizontally across the top right. * **Negative Bus Line:** Connects the top (-) terminals of all 10 speaker tiles in sequence. * **Positive Bus Line:** Connects the bottom (+) terminals of all 10 speaker tiles in sequence (note: the 3rd speaker tile in line shows reversed (+) and (-) polarities).

Installation and Wiring

Tools needed: Drywall knife, power drill and wire strippers.

1. Using the included template, mark the location of the mounting holes and cut an opening in the ceiling. Predrill the mounting holes and insert an anchor into each one.

2. Wire the speakers using the appropriate wiring configuration (see below).

25V/70V Wiring: 

Connect the red (positive) speaker cable to the appropriate 70 volt tap wire (fig. a). Connect the black (negative) speaker cable to the black COM (negative) tap wire (fig. b).

Detailed color wiring diagram showing multiple transformer tap leads extending from a speaker assembly, highlighting specific wire connections: * **Transformer Tap Wires (Fan-Out Array):** * **Outer Upper Wires:** Brown, purple, orange, and grey wires extend out and frame the sides of the wire bundle down to exposed stripped leads. * **Inner Lower Wires:** Blue, green, pink, yellow, red, and black wires extend downward with exposed stripped leads. * **Wire Splicing Callouts:** * **a (Positive Connection):** A red incoming wire marked **a** is twisted together with the yellow transformer wire. * **b (Negative Connection):** A black incoming wire marked **b** is twisted together with the black transformer wire.

8 ohm Wiring: 

Disconnect the black wire and the white wire from the connector (fig. c). Connect the black (negative) speaker cable and the red (positive) speaker cable to the corresponding ports on the connector (fig. d).

Two-panel line-art diagram detailing the use of lever-nut wire connectors to splice speaker wiring: * **Panel c (Connecting Primary Wires):** * A 2-port lever wire connector receives a red-and-black paired wire into the front entry ports. * Two arrows pointing upward and to the right from the rear ports labeled **c** indicate inserting two outgoing stripped wires into the connector. * **Panel d (Connecting Loop-Through / Secondary Wires):** * Shows the same 2-port lever connector with wires already secured in the rear. * Two arrows pointing straight up into the front ports labeled **d** indicate inserting a second set of stripped positive (red/black) and negative (black) wires into the remaining entry ports to pass through or loop the audio signal.

3. Carefully insert all cables into the precut opening and cap off any unused taps or wires (fig. e). Now insert the speaker into the opening until the mounting plate sits snug against the ceiling (fig. f). Align the mounting holes with the predrilled holes. Use four of the eight included screws to secure the speaker (fig. g). Do not overtighten.

Line-art installation diagram labeled "**e**" illustrating how to route transformer wires through a ceiling structure: * **Speaker Assembly (Bottom):** Displays an in-ceiling speaker driver mounted face-down with an attached step-down transformer on its rear frame. * **Wire Routing through Ceiling:** * Two bold black arrows point straight upward, indicating to feed the bundle of colored transformer wires up through a cutout in the ceiling panel (shown cross-hatched). * **Wire Management (Above Ceiling):** * **Unused Wires:** Three unused transformer tap wires (blue, green, red) extend into the ceiling cavity and are capped together at the end with an orange wire nut (twist-on wire connector). * **Connected Wires:** The active wires—a black wire and a yellow wire—extend to the right above the ceiling line and connect to incoming positive (red) and negative (black) audio lines via twisted wire splices.

Side-profile line-art installation diagram showing how to flush-mount a speaker assembly to a ceiling tile: * **f (Faceplate / Bezel Position):** An arrow labeled **f** points to the outer rim flange of the speaker's front faceplate, which sits flush against the bottom surface of the cross-hatched ceiling panel. * **g (Securing Screw):** A pointed mounting screw marked **g** is positioned below a pre-drilled mounting hole. A bold black arrow points straight up, indicating to drive the screw upward through the speaker bezel and into the ceiling structure to secure the assembly in place.

Adjusting the Speaker Volume

The MS81 features a built-in volume control camouflaged into the center of the grille allowing you to instantly change the volume level without needing to uninstall it.

Close-up line-art diagram illustrating how to release or remove the front grille from a ceiling speaker assembly: * **Grille Removal / Lever Mechanism:** A person's fingers are shown reaching up to pinch or press a small release tab located along the inner rim of the speaker's outer frame. A bold black arrow points directly to the tab, indicating where to apply pressure to detrend or unlatch the speaker grille.

Dimensions

Dimensional line-art drawing showing side-profile and front views with physical specifications for a square in-ceiling speaker assembly: * **Side Profile View (Left):** * **Mounting Depth:** Labeled along the top horizontal dimension as **3.5" (88.9mm)** from the rear of the faceplate flange to the back of the magnet assembly. * **Overall Diameter:** Labeled along the central vertical dimension as **12.51" (318mm)** across the height of the front square faceplate. * **Cut-out Diameter:** Labeled along the rear vertical dimension of the speaker cone basket as **8" (203.2mm)**. Loose wire leads extend out from the back of the speaker driver. * **Front View (Right):** * **Mounting Diameter (Width & Height):** Labeled across the top horizontal and right vertical dimensions as **10.98" (279mm)**, measuring the distance between the four corner mounting screw holes. * **Grille & Faceplate:** Displays a square faceplate with rounded corners featuring a centered circular pattern of perforated grille holes.

Features/Specifications

  • Pair of Rockville MS81 8˝ Commercial 70v/25V In-Ceiling Metal Speakers for background music and PA applications
  • Metal housing is rugged, reliable and blends in nicely with standard ceiling designs.
  • Built-in volume control allows you to set the volume from the front! Note: The control is camouflaged into the center of the grille and is easily accessible without removing the speaker.
  • 8 Ohm transformer by-pass allows you to use this speaker for standard 8 ohm applications.
  • These are the most common style of speakers for large retail stores, schools and many other applications.
  • Paper woofer cone is very sensitive allowing for high volume levels even if you set the tap at only 0.5 watts.
  • The 8˝ cone moves a ton of air and gives this speaker a deeper bass response then 6.5˝ or 5.25˝ options.
  • Dual cone driver allows these to play a full frequency range with increased sensitivity. For many commercial applications, this can be much better then having a separate high frequency driver.
  • Steel Grills
  • Frequency Response: 70Hz – 20KHz
  • Sensitivity: 90dB @ 1w/1m
  • Maximum SPL (Pax/1m): 100dB
  • Magnet: 5oz Ferrite
  • Dispersion @ 1000Hz: 120º conical
  • Overall Diameter: 12.51˝
  • Mounting Diameter: 10.98˝
  • Mounting Depth: 3.5˝
  • Cut-out Diameter: 8˝
  • Weight: 2.7lbs (each)
  • Color: off-white

 

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