Niles Audio Ultimate Guide to Your Niles SPS4 Stereo System

TECH TIP

Wire size is expressed by its AWG (American Wire Gauge) number. The lower the AWG number, the larger the wire. Thus, 12 AWG wire is physically larger than 14 AWG.

W E A T H E R P R O O F M U T I N G S T E R E O V O L U M E C O N T R O L S

W E A T H E R P R O O F M U T I N G S T E R E O V O L U M E C O N T R O L S

• Isolated left- and right-channel grounds ensure safety with

any amplifier.

• May be used with 4-, 6-, or 8-ohm speaker systems.

• Ideal for home and commercial sound installations.

• UL-rated to comply with all local building codes.

• Installation requires only a screwdriver and wire stripper.

CAUTION! Every speaker pair in the system must be connected to an impedance-magnifying volume control and set to the same magnification.

1. Count the	number of pairs of
4-ohm speakers and the number
of pairs of	8-ohm speakers you

TOOLS REQUIRED

• 1/8" Standard

Slotted Screwdriver

• 1/4" Standard

Slotted Screwdriver

In a typical application of IM volume controls, a system has eight pairs of 8-ohm speakers through- out the house. Each pair of speakers is connected to an IM volume control with its switches set for 8x.

12 AWG

14 AWG

reduce your maximum volume substantially. To solve this prob- lem, specify a speaker selector with a defeatable protection circuit (Niles models HDL-4, HDL-6, SPS-4, or SPS-6). Then keep the protection circuit off at all times.

JUNCTION BOXES

WMVC 100: The mounting depth of the MVC 100 is 2-9/16". When installed, the unit extends 2-1/16" behind the sheetrock

• Power handling: 100W/channel RMS.

are connecting. Count pairs of

6-ohm speakers as 4-ohm pairs.

• Wire Stripper

With eight pairs of speak- ers, one-eighth of the amplifier’s power is avail-

wall (assuming 1/2" sheetrock). For installation, use a standard 18-cubic-inch (or larger) junction box. Suitable junction boxes are available from your Niles dealer or local electrical-

• Frequency response: 20Hz to 20kHz ±1.5dB.

• WMVC 100: Available colors: Bone and White.

• 10 years parts and labor warranty.

INSTALLATION CONSIDERATIONS

Calculating the Impedance Magnification Setting

Use the following instructions and the accompanying charts to select the correct switch setting for the number and type of speakers in your system.

2.Determine whether the amplifier should see a 4-ohm load or an 8-ohm load. You should find this information in the owner’s manual of the amplifier.

3.Read the correct switch position from the charts on the next page. See Figure 3 if your amplifier can drive a 4-ohm load. See Figure 4 if your amplifier must have an 8-ohm speaker load.

4.Set the switches on all of the controls to the same position (1x, 2x, 4x, or 8x).

Limitations in Volume with High Magnification Settings

Using an 8x setting limits the power to each speaker pair to one-eighth of the amplifier’s output.

able to any pair. Therefore, an amplifier rated at 100W per channel RMS into 8 ohms will deliver up to 12.5W to each of the eight pairs – whether you play all eight pairs or just one pair. This translates into a drop in the maximum volume capability of about 9dB at the 8x setting.

USING SPEAKER SELECTORS WITH IM VOLUME CONTROLS

Although IM controls provide volume and on/off at the volume- control location, they do not give you central control of speak- ers playing throughout the house.

Speaker-selection systems give you central control, but some speaker selectors have non-defeatable impedance-protection circuits. Combining IM controls with such a selector will

supply company.

WMVC 100E: Use the PVC junction box (supplied), mounted atop a PVC conduit through which the wires will run.

TYPE OF SPEAKER WIRE

We recommend 16-gauge stranded copper speaker wire for most connections, and 14-gauge wire for runs longer than 80 feet. Don’t use speaker wire larger than 14 gauge, because larg- er wire may not fit into the connectors. Never use solid-core, aluminum, or Romex wire with an IM volume control. For speaker-wire runs within walls, most U.S. states and munici- palities require a special type of speaker wire with a specific CL fire rating, such as CL-2 or CL-3. Consult your Niles dealer, building contractor, or local building-inspection department if you aren’t sure what kind of wire is best for your application.

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