Niles AB-2D Original operating instructions

AB-2D
INSTALLATION & OPERATION GUIDE
NILES
®
MODEL
AB-2D
SPEAKER A,B OR A+B SELECTOR
AB-2D

Introduction
The AB-2D is a wall-mount, Decora®style A, B or A+B speaker
selector. The unit has one amplifier input and two speaker
pair outputs. With the AB-2D, you can select an amplifier to
play into either pair of loudspeakers (A or B), or both pairs
simultaneously (A+B).
Features and Benefits
The AB-2D offers a number of improvements over other A-B
selectors.
●Interchangeable Decora inserts for fast, easy color change.
Inserts and buttons (sold separately) are available in a vari-
ety of colors.
●Self-cleaning, silver-plated switch contacts assure many
years of trouble-free use.
●Printed circuit board design uses no hand wiring, assuring
high reliability.
●The circuit board connectors can accommodate up to 14
gauge wire, making the AB-2D compatible with most
“high definition” speaker cables.
TABLE OF CONTENTS
Introduction 1
Features and
Benefits 1
Installation
Considerations 3
Installation 8
Operation 10
Specifications 10
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AB-2D
Speaker/Amplifier
Selector
1

●100% tested, electronically and acoustically, for frequency
response, distortion and power handling.
●Isolated left and right channel grounds make it safe for use
with any amplifier.
●May be used with 4, 6, or 8 ohm speaker systems.
●Ideal for both home and commercial sound installations.
●Only screwdriver and wire stripper required for installation.
●Power handling: 600 watts/channel continuous power
(RMS).
●Frequency response: Flat from 20 Hz to 20 kHz.
●Available colors: White, Bone, Almond, or Black.
●Ten year parts and labor warranty.
●Proudly made in the USA.
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Installation Considerations
The AB-2D is a Decora-style module and is designed to use
standard Decora-style cover plates and mounting hardware.
Decora cover plates (up to 6-gang) with color-matched plate
screws are available from your Niles dealer.
Amplifier Impedance Load
When both pairs of speakers are selected on the AB-2D,
they are connected to the amplifier in parallel. This will
lower the overall impedance load presented to the amplifi-
er. For example, if two pairs of 8 ohm speakers are selected
on the AB-2D, their parallel impedance will be 4 ohms; 2
pairs of 4 ohm speakers in parallel become 2 ohms, and so
on. The AB-2D does not provide impedance protection for
the amplifier. Consult your Niles dealer if you are unsure
about your amplifier's low impedance drive capability. A
Niles impedance protection device may be required.
P-Rings and Electrical Boxes
The mounting depth of the AB-2D is 2 1/2". When installed,
the unit extends 2" behind the sheetrock wall (assuming 1/2"
sheetrock). For installation, you must choose between a stan-
dard light switch plaster ring (p-ring) or a standard 18 cu. in.
(or larger) electrical box. Suitable p-rings and electrical boxes
are available from your Niles dealer or local electrical supply
company. Using the p-ring is best because it gives you unob-
structed access to the full depth of the wall. In some instances,
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TOOLS
REQUIRED
• No. 2 Phillips
Screwdriver
• 1/8" Standard
Slotted Screwdriver
• 1/4" Standard
Slotted Screwdriver
• Wire Stripper
"TECH TIP"
Verify that the
impedance
presented to the
amplifier when both
speaker pairs are
selected is above
the minimum
recommended by
the amplifier
manufacturer.

the use of a p-ring may be inappropriate, such as in a retro-fit
(existing) installation, or when building codes require that
wall devices be enclosed in electrical boxes. Contact your local
building code and inspection department if unsure.
Type of Speaker Wire
For most applications, we recommend you use 16 or 18
gauge, stranded copper speaker wire for the AB-2D connec-
tions. For wiring runs longer than 80 feet, 14 gauge wire is
recommended. Using speaker wire larger than 14 gauge for
the AB-2D connections is not recommended—the wire may
not fit into the connectors. Never use solid-core, aluminum,
or "Romex" type wire with the AB-2D. When running speaker
wires inside walls, most states and municipalities in the U.S.
specify that you must use a special type of speaker wire.
Usually, the requirement is that the wire has a specific "CL"
fire rating, such as "CL-2" or "CL-3". Consult your Niles deal-
er, building contractor, or local building and inspection
department if unsure about which type of wire is best for
your application.
AB-2D Mounting Location
Convenient mounting locations for the AB-2D are:
●Near entry-ways or exits
●Near a desk
●At your bedside
●Close to a telephone 4
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"TECH TIP"
Wire size is
expressed by it's
AWG (American
Wire Gauge)
number. The lower
the AWG number,
the larger the wire,
i.e., 12 AWG wire is
physically larger
than 14 AWG.

●Near other wall controls (see caution below)
DO NOT INSTALL THE AB-2D INTO ELECTRICAL BOXES
WITH 110 VOLT DEVICES.
Some states or municipalities allow devices such as the AB-2D
to be installed into the same electrical box as 110 volt
devices, provided a "low-voltage partition" is used between
the devices. We do not recommend this. Speaker wires can
act as an "antenna" for electrical noise. Locating speaker wires
too close to a light switch or dimmer may cause a "popping"
or "buzzing" sound to be heard through the speakers. If you
must locate the AB-2D near electrical devices, install it in a
separate metal electrical box, ground the box to the electri-
cal system ground, and route the speaker wires several feet
away from the electrical wiring.
Changing the Color of the AB-2D
The Decora insert and buttons on the AB-2D are removable,
allowing fast and easy color changes as needed. Inserts and
buttons are available in a variety of colors.
If you need to change the color of the AB-2D:
1. Obtain the AB-2D Decora insert and buttons in the
desired color from your Niles dealer.
2. Holding the AB-2D as shown in (Figure 1), locate the two
plastic mounting tabs at the top rear of the Decora insert.
Using two fingers, simultaneously press both tabs down
(towards the center of the insert) and forward (away from
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you) until the insert pops free from its mounting slots.
3. Hold the AB-2D as shown in (Figure 2). Remove both
buttons from the switches using your fingers. DO NOT use
pliers or other tools as these may damage the buttons.
4. Locate the new Decora insert. Hold the AB-2D so that it
is facing you. Insert the two bottom tabs into the bottom
slots first, followed by the two tabs on the top. Snap the
insert into place by carefully pressing on the front of the
insert.
5. Locate the new buttons. Secure the buttons to the
switches by gently pressing them into place.
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Figure 2
Removing the
Button
Figure1
Removing the
Decora-style Insert
"TECH TIP"
Do not exert
excessive pressure
on the plastic
mounting tabs.

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(a) Electrical Box
(b) Speaker Wire
(c) AB-2D Speaker Selector (supplied)
(d) Snap-on Color Insert (supplied)
(e) Buttons (2 supplied)
(f) Device Screws (2 supplied)
(g) Decora Faceplate (supplied)
(h) Faceplate Screws (2 supplied)
b
c
d
e
f
g
h
a

Installation
If you are installing the AB-2D into an existing wall, take time
to consider any possible obstructions which may be hidden
inside the wall, such as wood and metal studs; electrical, tele-
phone or other types of wiring; plumbing; conduit; old
wall safes; etc.
1. Install the electrical box or p-ring in the usual
manner.
2. Run all the necessary wiring to the AB-2D. Label the
wires for future reference.
3. Make the connections to the AB-2D. Strip 1/4" of
insulation from the end of each wire. Tightly twist the
end of each wire until there are no frayed ends. Insert
each wire into the appropriate hole on the connector
blocks; secure the wiring to the connectors by tighten-
ing the small connector screws. Be certain that proper
phasing is observed—connect the positive terminals
on the AB-2D to the positive terminals on the amplifier
and speakers and the negative terminals on the AB-2D
to the negative terminals on the amplifier and speakers.
See (Figure 3).
The input of the AB-2D is the connector labeled "AMP".
The outputs are the connectors labeled "A" and "B". Be
sure not to reverse any of these connections or the AB-2D
will not function properly.
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AB-2D
Speaker
Pair B Speaker Pair A
Receiver
Figure 3
Wiring Diagram

4. Secure the AB-2D to the electrical box or p-ring. Insert the
1 1/4" long device screws into the oblong-shaped screw holes
on the top and bottom of the AB-2D. Note that the oblong
shape of the screw holes allow you to position the AB-2D so
that it is vertical. Position the AB-2D so that the screws are
aligned with the threaded holes in the electrical box or p-
ring. Tighten the screws using a phillips screwdriver. DO
NOT OVER-TIGHTEN. In some instances, you may need to
loosen these screws several turns to allow the AB-2D to fit
flush with the Decora cover plate. See (Figure 4).
5. Use the shorter plate screws to fasten the Decora cover
plate to the AB-2D. DO NOT OVER-TIGHTEN THE PLATE
SCREWS OR YOU MAY DAMAGE THE COVER PLATE. Line up
all the screws in the same direction for a finished look.
NOTE: Certain "old work" or "retro-fit" boxes, such as the
Carlon B225R, have a plastic "lip" which interferes with the
Decora plate screws. This lip prevents you from being able to
tighten these screws completely. To make the clearance nec-
essary for these screws, you must remove the parts of the lip
causing the interference. There are two ways to accomplish
this:
1. Drill through the lip of the box at the screw points.
2. Cut notches into the lip with a pair of diagonal cutters.
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Figure 4
Loosening the Screws
for a Flush Fit

Operation
1. Make sure the amplifier or receiver power is OFF and set
the volume to minimum.
2. Set both selector buttons on the AB-2D to the OFF posi-
tion (buttons out).
3. If you are using a Niles speaker selection system in con-
junction with the AB-2D, locate the ON/OFF button which
corresponds to the AB-2D. Set it to the ON position.
4. Turn on the amplifier or receiver and select a source, such
as the tuner or CD player.
5. Using the selector buttons on the AB-2D, select the speak-
er pairs you wish to play.
6. Slowly turn up the amplifier or receiver volume and set it
to a comfortable (not maximum) listening level. Be careful
not to overdrive or "clip" your amplifier. If the sound becomes
muddy or distorted, you have reached the limit of your
amplifier's volume capability and should quickly reduce the
volume to avoid damaging your speakers.
Note: If the speaker pairs connected to the AB-2D are
equipped with Niles volume controls, adjust the volume of the
speakers to the desired listening level using the Niles controls.
If all the speaker pairs in your system are equipped with Niles
volume controls, you can leave the amplifier or receiver vol-
ume set at one position and use the Niles controls exclusively.
7. You can turn off the speakers by simply pressing the
ON/OFF buttons on the AB-2D you wish to play. 10
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SPECIFICATIONS
Audio Power
Handling
600 Watts/channel
continuous power
(RMS)
Mounting
In-wall, requires single-
gang electrical box at
least 3" deep, Decora-
style face plate
Wiring Requirements
Individual runs of
2-conductor speaker
wire, 14-22 gauge
Unit Dimensions
11/8" wide x 2 5/8"
high
Face Plate Dimensions
Decora wall plate;
2 3/4” wide x 4 1/2”
high
Depth Behind Plate
2 1/2”

Niles Audio
Corporation
www.nilesaudio.com
12331 S.W. 130 Street
Miami, Florida 33186
Tel: [phone]
Fax: [phone]
©1999 Niles Audio Corporation
DS00104A
®
NILES
®