Niles HDL-4 Original operating instructions

HDL-4
INSTALLATION & OPERATION GUIDE
MODEL
HDL-4
HIGH DEFINITION SPEAKER SELECTION SYSTEM
HDL-4

Introduction
The HDL-4 allows you to connect up to four pairs of speakers
to your stereo receiver or amplifier and play any one pair, any
combination of pairs, or all pairs at once. You don't have to
worry about overloading your amplifier. The HDL-4 has a pro-
tection circuit that keeps your amplifier running safely, even
if you have all four pairs of speakers playing at the same time.
TABLE OF CONTENTS
Introduction 1
Features and
Benefits 2
Installation
Considerations 4
Installation 9
Operation 11
Specifications 14
HDL-4
High Definition
Speaker Selector
System
1
H IGH D EFINITION S PEAKER S ELECTION S YSTEM

Features and Benefits
The HDL-4 offers a number of improvements over other
speaker selectors:
●High power handling capability of 250 watts/channel
continuous music power.
●Pre-printed Room Labels are included for easy identification
of speaker ON/OFF buttons.
●Rear-panel switch for constant or selectable impedance
protection.
●Self-cleaning, silver-plated switch contacts assure many
years of trouble-free use.
●Isolated left and right channel ground returns make the
HDL-4 compatible with all types of amplifiers.
●Massive copper traces on printed circuit board handle
large amounts of amplifier current, ensuring high dynamic
range and clarity.
●May be used with 4, 6, or 8-ohm speaker systems.
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H IGH D EFINITION S PEAKER S ELECTION S YSTEM
TECH
SUPPORT
HOTLINE
If you have
questions regarding
the operation of the
Niles HDL-6, contact
your local Niles
dealer or Niles
Customer Service at
1-800-289-4434.

●Two-piece removable connectors greatly simplify installa-
tion and hookup. All wiring can be attached directly to the
connectors before installing them in the HDL-4.
●Removable connectors accommodate up to 14 gauge wire
or "pins", making the HDL-4 compatible with most "high-
definition" speaker cables.
●100% tested, electronically and acoustically, for frequency
response, distortion and power handling.
●Standard 17" width allows the HDL-4 to stack neatly with
other standard size components.
●Ideal for both home and commercial sound installations.
●Only an 1/8" standard screwdriver and wire stripper are
required for installation.
●Frequency response: Flat(+0dB,-0dB) from 20Hz to20kHz.
●Ten year parts and labor warranty.
●Proudly made in the USA.
3
H IGH D EFINITION S PEAKER S ELECTION S YSTEM

Installation Considerations
HDL-4 Power Handling
The HDL-4 is designed for use with a receiver or amplifier
having a maximum power output of 250 watts per channel
at 8 ohms. Damage caused by the use of a higher-power
receiver or amplifier will void the warranty. Consult your Niles
dealer, or receiver/amplifier manufacturer, if you are uncer-
tain about the power rating of your receiver or amplifier.
Amplifier Impedance Load
As more pairs of speakers are parallel connected to a receiver
or amplifier, the overall system impedance becomes lower.
For example, if two pairs of 8-ohm speakers are connected
in parallel, the impedance will be 4 ohms; two pairs of
4-ohm speakers in parallel become 2 ohms, and so on.
Most receivers or amplifiers are not rated for use below a 4
ohm load. Most manufacturers do not recommend connect-
ing more than two pairs of speakers without using some
form of impedance correction.
The HDL-4 includes impedance correction circuitry which
protects your receiver or amplifier from low impedance
loads. The circuitry assures that your receiver or amplifier will
see a safe operating load, even when all four speaker pairs
are playing at the same time. 4
H IGH D EFINITION S PEAKER S ELECTION S YSTEM
TOOLS
REQUIRED
• 1/8" Standard
Slotted Screwdriver
• Wire Stripper

The actual impedance load the HDL-4 presents to your
receiver or amplifier will vary, depending on how many
speaker pairs are playing, and the impedance rating of each
speaker. If you have four pairs of 8-ohm speakers playing, the
HDL-4 will present a 4.5 ohm impedance load to your receiv-
er/amplifier. With four pairs of 4-ohm speakers playing, the
load drops to slightly under 4 ohms.
If you intend to use the HDL-4 with more than two pairs of
4-ohm speakers, it is recommended that you verify that the
receiver or amplifier is capable of driving a 4-ohm load. Consult
your Niles dealer, or receiver/amplifier manufacturer, if you are
uncertain about the capabilities of the receiver/amplifier.
Type of Speaker Wire
For most applications, we recommend you use 16 or 18 gauge,
stranded copper speaker wire for the HDL-4 connections. For
wiring runs longer than 80 feet, 14 gauge wire is recommend-
ed. Using speaker wire larger than 14 gauge for the HDL-4
connections is not recommended—the wire may not fit into
the connectors. Never use solid-core, aluminum, or "Romex"
type wire with the HDL-4. 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 dealer, building contrac-
tor, or local building and inspection department if unsure
about which type of wire is best for your application.
5
H IGH D EFINITION S PEAKER S ELECTION S YSTEM
"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

Avoiding Interference
Speaker wires can act as an "antenna" for electrical noise.
Locating speaker wires too close to a light dimmer or switch
may cause a "buzzing" or "popping" sound to be heard
through the speakers. If you must locate the HDL-4 wiring
near electrical devices, route the speaker wires several feet
away from the electrical wiring.
Using the HDL-4 with Tube-Type Amplifiers
Virtually all tube amplifiers must have a load connected at all
times. If the amplifier to be connected to the HDL-4 is a tube
amplifier, be sure to always have at least one pair of speakers
switched on at all times. An alternative is to permanently
connect a 150 ohm, 5 watt resistor across the tube amplifier's
output in parallel with the HDL-4. See (Figure 1) on next
page for hookup diagram.
6
H IGH D EFINITION S PEAKER S ELECTION S YSTEM

7
H IGH D EFINITION S PEAKER S ELECTION S YSTEM
Figure1
Using a
Tube Amplifier
Tube Amplifier
Niles HDL-4
150 150
AMPLIFIER
L+ L- R- R+ L+ L- R- R+ L+ L- R- R+ L+ L- R- R+ L+ L- R- R+
SPEAKER 4 SPEAKER 3 SPEAKER 2 SPEAKER 1
CONSTANT
PROTECTION
ON OFF
Niles Audio
Corporation,
Miami, Florida USA

8
H IGH D EFINITION S PEAKER S ELECTION S YSTEM
AMPLIFIER
L+ L- R- R+ L+ L- R- R+ L+ L- R- R+ L+ L- R- R+ L+ L- R- R+
SPEAKER 4 SPEAKER 3 SPEAKER 2 SPEAKER 1
CONSTANT
PROTECTION
ON OFF
Niles Audio
Corporation,
Miami, Florida USA
Recessed
areas for
custom room
labels.
Attractive
low-profile
design.
Simple
push-button
operation.
Connect up to four pairs
of speakers. Protection switch safeguards your
receiver or amplifier even with all
4 pairs of speakers playing.
Two-piece
removable
connectors.
Constant
Impedance
Protection
Switch

9
H IGH D EFINITION S PEAKER S ELECTION S YSTEM
Installation
1. Select a convenient mounting location for the HDL-4.
2. Run all the necessary wiring to the HDL-4. Label the wires
for future reference. See (Figure 2).
TUNER 94.9
15
AMPLIFIER
L+ L- R- R+ L+ L- R- R+ L+ L- R- R+ L+ L- R- R+ L+ L- R- R+
SPEAKER 4 SPEAKER 3 SPEAKER 2 SPEAKER 1
CONSTANT
PROTECTION
ON OFF
Niles Audio
Corporation,
Miami, Florida USA
Niles HDL-4
Receiver
Speaker
Pair 4 Speaker Pair 3 Speaker Pair 2 Speaker Pair 1
Figure2
Wiring Diagram

3. Make the connections to the HDL-4. The amplifier/speaker
connectors on the HDL-4 are removable. If you wish, you
may remove the HDL-4's connectors to facilitate installation
see (Figure 3). Strip 3/8" 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
spring-loaded connector terminals. Be certain that proper
phasing is observed—connect the positive terminals on the
HDL-4 to the positive terminals on the amplifier and speakers
and the negative terminals on the HDL-4 to the negative ter-
minals on the amplifier and speakers. Re-install the connec-
tors if they were removed. See (Figure 4).
4. Locate the pre-printed Room Labels. Affix the appropriate
label to the recessed area over each ON/OFF selector button.
10
H IGH D EFINITION S PEAKER S ELECTION S YSTEM
Figure3
Removing the Connectors Figure4 Installing the Connectors

11
H IGH D EFINITION S PEAKER S ELECTION S YSTEM
Operation
There are two ways to use the HDL-4. You may play one pair
of speakers at a time, or play multiple pairs simultaneously.
If you intend to play more than one pair of speakers at the
same time, you will need to become familiar with the opera-
tion of the HDL-4's PROTECTION button.
Playing One Pair of Speakers At a Time
1. Make sure the amplifier or receiver power is OFF and set
the volume to minimum.
2. Locate the ON/OFF button on the HDL-4 which corre-
sponds to the speaker pair you wish to play. Set it to the ON
position.
3. Turn on the amplifier or receiver and select a source, such
as the tuner or CD player.
4. 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.
5. To turn off the speaker pair, simply press the correspond-
ing ON/OFF button on the HDL-4.
"TECH TIP"
If your amplifier or
receiver has "A"
and "B" speaker-
pair outputs,
connect the HDL-4
to the "A" outputs.
Do not connect
anything to "B".
This will prevent
the amplifier or
receiver from driving
an unusually low
impedance load.

12
H IGH D EFINITION S PEAKER S ELECTION S YSTEM
Playing Two or More Speaker Pairs Simultaneously
1. Make sure the amplifier or receiver power is OFF and set
the volume to minimum.
2. On the right side of the HDL-4's front panel is a button
labeled PROTECTION. This button activates the HDL-4's
impedance correction circuitry. The circuitry assures that
your receiver or amplifier will see a safe operating load when
playing multiple speaker pairs simultaneously. Since most
receivers and amplifiers are not rated for use below a 4 ohm
load, you will need to activate the PROTECTION button
whenever the overall system impedance might fall below 4
ohms. Use the following chart as a guide for setting the
PROTECTION button.
3. Locate the ON/OFF buttons on the HDL-4 which corre-
spond to the speaker pairs you wish to play. Set them to the
ON position.
"TECH TIP"
You will need to
activate the HDL-4's
PROTECTION button
whenever the overall
system impedance
might fall below
4 ohms.
When playing the following speakers:
1 or 2 pair of 8-ohm speakers
3 or 4 pairs of 8-ohm speakers
1 pair of 4-ohm speakers
2, 3, or 4 pairs of 4-ohm speakers
Any combination of 4 and 8 ohm speakers
The Protection button should be:
OFF
ON
OFF
ON
ON
Set the PROTECTION button to the correct position using the chart shown above.

4. Turn on the amplifier or receiver and select a source, such
as the tuner or CD player.
5. 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.
6. To turn off one or more speaker pairs, simply press the cor-
responding ON/OFF button(s) on the HDL-4. Refer to the
Protection chart for the correct setting of the PROTECTION
button.
Constant Protection Switch
The HDL-4 is equipped with a manual override for the protec-
tion circuit that enables you to defeat the front panel protection
switch and maintain constant impedance protection. This will
safeguard your amplifier from being overdriven due to acciden-
tal or improper use by anyone unfamiliar with the equipment.
To engage this override, move the rear panel "CONSTANT
PROTECTION" switch to the "ON" position. Constant impedance
protection will be maintained until the switch is turned to "OFF".
13
H IGH D EFINITION S PEAKER S ELECTION S YSTEM

14
H IGH D EFINITION S PEAKER S ELECTION S YSTEM
Balancing Speaker Volume
The volume control on your receiver or amplifier serves as the
"master" volume for all speaker pairs connected.
The volume level of the speakers may vary from room to room.
This is caused by several factors. Two lesser factors are the size
of the speaker and its efficiency. The largest factor is the physi-
cal size of the room.
The best way to balance speaker volume is to equip each of the
speaker pairs in your system with a Niles volume control. The
controls allow you to adjust the volume of each speaker pair
individually. If all the speaker pairs in your system are equipped
with Niles volume controls, you can leave the amplifier or
receiver volume set at one position and use the Niles controls
exclusively.
SPECIFICATIONS
Audio Power
Handling
250 watts/channel
continuous music
power
Frequency Response
+0 dB, -0 dB (flat) from
20 Hz to 20 kHz
Mounting
Table-Top component
Wiring Requirements
Individual runs of
2-conductor speaker
wire. Connectors
accommodate wire
sizes 14-22 gauge (16
gauge recommended)
Overall Dimensions
17" wide x 2" high x
8-3/4" deep
Weight
4 1/2 lb.

Niles Audio
Corporation
www.nilesaudio.com
12331 S.W. 130 Street
Miami, Florida 33186
Tel: [phone]
Fax: [phone]
NILES
®
©1999 Niles Audio Corporation. Niles and the Niles logo are registered trademarks of Niles Audio Corporation.
Printed in USA 2/99 DS00099A