I N S T A L L A T I O N & O P E R A T I O N G U I D E
I N S T A L L A T I O N & O P E R A T I O N G U I D E
CM8SW
SUBWOOFER
®
B L E N D I N G H I G H F I D E L I T Y
®
A N D A R C H I T E C T U R E
Features and Benefits
TCC Speaker Cone
High-Power Handling
The Niles CM8SW is a high-performance The CM8SW employs an exceptionally
passive subwoofer that compliments the heavy-duty magnet/voice-coil/spider
entire Niles ceiling mount loudspeaker assembly that is capable of handling high
line. It’s dual voice-coil injection molded power amplifiers (up to 150 watts).
TCC (talc, carbon and ceramic) woofer
provides outstanding bass response
The illustration below shows how
a typical Niles CM loudspeaker
mounts into a ceiling.
New Construction Bracket serves as
a “hole saver” when drywall has not
been applied. It is not necessary when
retrofitting to existing ceilings.
Figure 1
Model CM8SW Shown
Knockout wire tie allows
the wire to be secured to
the bracket throughout the
new construction process.
It knocks out cleanly when
the speaker is installed.
New construction
wings instantly snap
into the bracket
without screws.
Dogs swivel 90°, then
clamp the speaker
frame to the drywall.
Frames are molded with
a slight texture to assure
good paint adhesion.
Mounting screws tighten
the “Dogs”, clamping the
speaker to the drywall
Wings are scored for
easy size trimming.
Brackets and wings
attach to the ceiling joists
with nails or screws.
Rust-proof aluminum Grilles make the
CM8SW series perfect for moist
environments.
Figure 2
Figure 3
SAT
SUB
140Hz
FULL
CUT
100Hz
The CM8SW ceiling mount subwoofer includes an
easy access, baffle mounted high pass filter to
prevent over-excursion of the satellite’s woofers.
The CM8SW ceiling mount subwoofer includes
an easy access, baffle mounted low pass fre-
quency selection switch.
2
Infinite Baffle Design
Easy Installation
The CM8SW is designed for optimum low
frequency reproduction in traditional ceil-
ing environments and varying air volumes.
It does not require a special enclosure to
provide high performance.
The CM8SW employs a bracketless
mounting system for existing ceilings.
Simply cut a hole in the mounting surface,
remove the grille from the subwoofer,
connect the wires and place the speaker
in the hole. Then tighten the four mount-
ing “dogs” via the front panel screws. The
dogs first swivel 90°, then clamp the frame
to the drywall as the screws are tightened.
Selectable High-Pass Filter
Installers can also select whether or not to
filter the low frequencies from the satellite
speakers at a fixed frequency of 120Hz.
Like the low-pass filter, this selection is
accessed via baffle mounted controls
(See Figure 2).
Hole Saving Bracket
Available as an optional accessory, the
CM8 New Construction Bracket can be
installed as a “hole-saver” before the dry-
wall goes up. The drywall contractor cuts
the hole as the drywall is installed, reduc-
ing installation time and minimizing the
chances for lost wires.
Adjustable Low Pass Filter
Installers can select passive crossover for
both woofer and satellite speakers via
baffle-mounted controls that are
accessible even after the subwoofer has
been installed (See Figure 3).
Weather-Resistant Construction
All components of the CM8SW are weath-
er resistant. The aluminum grille and stain-
less steel mounting screws are rustproof.
This makes the subwoofer ideal for moist
environments which would cause some
brands of speakers to discolor. Protected
outdoor installations are perfectly suited
for the CM8SW.
MicroPerf™ Grilles
The CM8SW employs Niles’ exclusive
MicroPerf grille construction. The excep-
tionally tight hole pattern provides
acoustic transparency at all audio frequen-
cies and enables the woofer element to
remain invisible. MicroPerf grilles can be
painted to blend seamlessly with the
surrounding decor.
No-Strip Speaker Wire Terminals
Dual Niles patented gold-plated no-strip
speaker wire terminal connectors accom-
modates 12-18 gauge wire.
3
How Many Subwoofers?
Single Stereo Subwoofer
For most applications a single CM8SW is One CM8SW can produce the bass sound
appropriate. However, in large rooms, high from both the left and the right channels
performance listening rooms or in home because of its unique dual voice coil
theaters, an array of two or more CM8SW design. One voice coil powers the left chan-
will deliver astounding results. Unlike nel and the other powers the right channel.
other subwoofer systems, a Niles A stereo crossover divides the signal and fil-
Subwoofer Array is concealed. Consider ters it according to the position of the
the distance between the subwoofer(s) and switches on the front panel. A single stereo
the listener, the size of the amplifier and subwoofer is compatible with any 4 ohm
the desired quality and volume of sound stable amplifier. Eight ohm stable amplifiers
when deciding how many CM8SWs to may be used with a Niles IM volume con-
install in your home.
trol (see Impedance section on Page 7)
Dual Subwoofer Systems
Decibels and Power
Using two CM8SW subwoofers in a system
raises the maximum attainable volume of
the system by 3dB. Additionally, at lower
volumes, excursion — and therefore distor-
tion levels — are reduced. In a large room,
or a home theater system, the effect on
bass quality is extremely desirable.
Another 2dB increase is possible if the
voice coils of each are CM8SW paralleled.
This requires a multi-channel amplifier or
an amplifier capable of driving the 2 to 2.6
ohm load of the overall system.
65dB
75dB
85dB
95dB
Conversation at three feet.
Sewing Machine at three feet.
Vacuum Cleaner at 10 feet.
Subway Train entering a station
at 20 feet.
3dB
The smallest difference of sound
the human ear can easily detect.
10dB
Perceived as twice as much loud-
ness if it is an increase (half as
much if it is a decrease).
Any speaker requires twice as much
amplifier power to increase 3dB and ten
times as much power to increase 10dB.
VLSA Installations
A Very Large Subwoofer Array (VLSA)
installation lowers the amount of excursion
required to achieve a high sound pressure
level. Lowering excursion dramatically
improves the quality of the sound. VLSA
installations are most appropriate when the
listener appreciates detail and bass exten-
sion, but must have a concealed installa-
tion. A VLSA of four subwoofers must have
a multichannel amplifier with one channel
assigned to each subwoofer.
Comparison of 1, 2 or 4 Subwoofers
16’ x 18’ x 8’ Room @ 12’
25 Watts 100 Watts
1 Sub
2 Subs
VLSA of 4 Subs 103dB
95dB
100dB
101dB
106dB
109dB
2 x Watts = 3dB Increase in Volume.
2 x Subs = 3dB Increase in Volume.
2 x Subs = 1/2 the subwoofer excursion for
the same volume.
If you double the distance from the sub-
woofer to the primary listening position
you decrease the volume by 4 to 6dB.
4
Dual Subwoofer Systems
Connections
A four conductor (Left+, Left-, Right+ and
Right-) wire 16 gauge or larger (see side-
bar on speaker wire gauge) is run from
the amplifier location to the local volume
control (See Figure 5).
Single Stereo Subwoofer
A four conductor (Left+, Left-, Right+ and
Right-) wire 16 gauge or larger (see side-
bar on speaker wire gauge) is run from the
amplifier location to the local volume
control (See Figure 4).
AmpliÞer
AmpliÞer
Left
Right
Left
Right
Either Input okay
Left and Right
No-Strip wire input termina
CM8SW
Wire to
Corresponding
Output
CM8SW
CM8SW
Left and Right
No-Strip wire output termin
Satellite Speaker
Satellite Speaker
Figure 5
A Dual CM8SW Hook-Up
Satellite Speaker
Satellite Speaker
From the local volume control a two con-
ductor cable is run to each of the CM8SWs
and connected to either the left or the right
Input connectors.
Figure 4
A Single CM8SW Hook-Up
From the local volume control the four
conductor cable is run to the CM8SW and Each of the satellite speakers must be con-
connected to the Input connectors. A two nected to the correct subwoofer. Typically,
conductor wire is connected to each of the a two conductor wire is connected to one
stereo outputs and fed to the left and right of the outputs on the left channel sub-
speakers. Now, the volume control will woofer and fed to the left satellite speaker
raise and lower the volume for the sub- and another two conductor wire connects
woofer and the left and right speakers the right channel subwoofer and satellite.
simultaneously. Additionally, the crossover
Now, the volume control will raise and
is now connected so that the crossover
lower the volume for the subwoofer and
switches can be adjusted.
5
the left and right speakers simultaneously. crossover) by a separate amplifier channel.
Additionally, the crossovers are now con- Connections are straight-forward; two
nected so that the crossover switches can conductor wires connect each amplifier
be adjusted to your requirements. You must channel to each individual subwoofer.
adjust the crossovers on each speaker with (See Figure 7).
this hook-up.
Optionally, a jumper of wire may be
connected between the L+ and the R+;
and between the L- and the R-. This con-
nects both voice coils of the CM8SW,
giving you a 2dB increase in output.
Since each subwoofer’s impedance
drops from 8Ω to 4Ω, make sure your
amplifier is 2Ω stable to accommodate
the satellite speaker’s impedance. (See
Figure 6).
Figure 7
Connections to a VLSA are normally made from
each CM8SW to a multi-channel amplifier like
the Niles SI-1230 twelve channel amplifier.
L
L
C
C
H
H
Each CM8SW has a jumper installed to
parallel the voice coils for maximum effi-
ciency. (See Figure 6).
CM8SW
L–IN
R–IN
The crossover controls on each subwoofer
affect only the subwoofer response. Level
controls on the amplifiers facilitate blend-
ing and compensation for placement.
Speaker Wire
Figure 6
Connecting the two voice coils in parallel with a
jumper (a piece of speaker wire).
For most applications, we recommend you
use 16 or 18 gauge wire. For wiring runs
longer than 80 feet we recommend 14
gauge wire. The No-Strip speaker wire ter-
minals can accommodate 12-20 gauge
wire. When you run wire inside walls, spe-
cial jacketing (CL-2 or CL-3) is required to
both protect the wire and for fire preven-
tion. In some areas conduit is required. For
a trouble-free installation, low voltage wire
such as speaker wire must be run in accor-
dance with the National Electrical Code
and any applicable provisions of the local
building code. Consult your local Niles
dealer or your building contractor if you are
unsure of code requirements in your area.
Very Large Subwoofer Array
(VLSA)
Using four or more CM8SW subwoofers
in a system creates a system of unprece-
dented clarity, with stunning bass impact
and potentially extraordinary maximum
volume capability. Because of the
extremely low impedance of a parallel
VLSA system, multiple channel amplifiers
are normally used to power them.
Because of this, in-wall volume controls
are incompatible with VLSA systems.
In a system of this type, it is recommended
that the satellite speakers be driven full
range (or with an external electronic
6
specification may also be noted on the rear
panel of the amplifier. If your amplifier is
not able to drive a four ohm load it may
only be used to power a CM8SW
satellite/subwoofer system when an imped-
ance magnifying volume control is incor-
porated into the system
Impedance
With One or Two Subwoofers
When one or two CM8SW subwoofers are
connected to the satellite speakers, the
overall system impedance to the amplifier
lowers.
An amplifier stable to four ohms may be
connected without impedance matching
devices. Parallel connections via the “A”
speaker terminals to one or two CM8SW
subwoofers (If the voice coils are not in par-
allel) and one pair of eight ohm satellite
speakers results in a four ohm load.
System Impedance in Ohms (Ω)
One or Two Subwoofers
8Ω Sats 4Ω Sats
1 Sub
2 Subs @8Ω each 4Ω
2 Subs @4Ω each 2.6Ω
4Ω
2.6Ω
2.6Ω
2Ω
The “B” speaker terminals cannot be used
to power a second pair of speakers any-
more. The low impedance drive capability
of your amplifier is already utilized by the
satellite/subwoofer combination. If you are
connecting other speakers in other rooms
you must install either a speaker selector or
impedance magnifying volume controls.
If the impedance is too low for your ampli-
fier utilize a Niles speaker selector or IM
volume control to match the impedance.
VLSA (Four or More Subwoofers)
A VLSA (Very Large Subwoofer Array)
installation lowers the amount of excur-
sion required to achieve a high sound
pressure level. Lowering excursion dra-
matically improves the quality of the
sound. VLSA installations are most appro-
priate when the listener appreciates detail
and bass extension, but must have a con-
cealed installation.
A few professional/audiophile amplifiers
advertise the capability of driving two
ohm speaker loads. These amplifiers may
be used without impedance matching
devices if the rating is quoted as “RMS” or
“Continuous” power and the amp does
not push too much power.
Each subwoofer should have its voice coils
connected in parallel for full output, there-
fore the impedance of each is four ohms.
Because of this low impedance, a multi-
channel amplifier stable to 4 ohms is the
best way to drive more than two sub-
woofers. Each CM8SW is connected to its
own channel of a multi-channel amplifier.
Check Your Amplifier’s Specs
Every amplifier has a minimum impedance
specifications. Check your owner’s manual
to determine whether or not your amplifier
is capable of driving a four ohm load. This
7
Using Speaker Selectors With
Standard Volume Controls
Using Impedance Magnifying
Volume Controls
In multi-room systems with standard vol- The simplest way to increase the imped-
ume controls any Niles speaker selector ance of a satellite/subwoofer system is to
will maintain a four ohm load if you leave install a Niles VCS-2D-IM or VCS-2S-IM
one set of room outputs unused for every impedance magnifying volume control
speaker system with an impedance of less instead of a standard volume control. This
than four ohms (such as a CM8SW con- control has a behind the wall jumper
nected to a pair of four ohm satellite which is set at the time of installation to
speakers). The protection switch must be “magnify” the speaker system impedance.
constantly engaged. Niles HDL series (See Figure 9).
speaker selectors have a rear panel con-
stant protection feature. (See Figure 8).
The benefit of a speaker selector is that
even with the protection circuit constant-
ly engaged, more power will be delivered
to any single pair of speakers playing by
itself (all other speakers off).
ª
In a multi-room system there is one indis-
pensible control for true convenience—a
local volume control. It allows you to
adjust the volume of the speakers and the
subwoofer without leaving the room.
For example: In the two times position, an
IM volume control will enable an eight
ohm stable amplifier to play a 4 ohm
speaker system without overheating. The
available power will decrease, which you
will perceive as a 3dB drop in maximum
undistorted volume.
Niles makes a wide range of high perfor-
mance indoor and outdoor volume controls
in Standard or Decora® style face plates
(just like your light switches and dimmers).
All of these volume controls enable full
power to be delivered to each speaker sys- If the jumper is set to the 4x position, a
tem when turned all the way up.
6dB drop in volume will be perceived.
If the jumper is set to the 8x position, a
9dB drop in volume will be perceived.
The combination of a speaker selector and
a standard volume control will deliver
high volume when only one pair of speak-
ers is playing.
A 10dB drop is perceived as half as loud,
so there are limits to the amount of magni-
fication you can use unless the amplifier is
very powerful (3dB increase every time
you double the power) or you never listen
at high volumes. Consult the Decibels and
Power chart on page 4.
8
™
ous brands available, e.g. Dynamat ).
Apply the damping material to the bottom
of the floor above the CM8SW and to the
top of the surrounding sheetrock ceiling
beside the subwoofer.
Treatment & Placement
Typically, sheetrock encloses the sub-
woofer in most installations. Sheetrock has
a fairly loud resonant “twang” compared
to the rigid non-resonant enclosures of
most floor standing subwoofers. None of
the following modifications are absolutely
necessary, however any one or combina-
tion of them will improve the performance
of the subwoofer.
Speaker Placement Techniques
Although the CM8SW has extensive ability
to compensate for unusual placements with
its crossover switches; placement is still the
primary tool for satisfying your particular
listening needs.
Maximizing Output
Minimum Enclosure Size
Corner Placement – Placing your subwoofer
near a corner will increase the volume of
bass sound produced by the subwoofer!
This is called the boundary effect. Generally,
you can expect a 3dB increase in sound
pressure level with corner placement.
The CM8SW will produce magnificent
results if the ceiling air cavity above the
woofer is a minimum of 1900 cubic inch-
es. If the ceiling joists center measure
5-1/2” deep (2x6) and are spaced 14-1/4”
apart (16” spacing) you would want the
length of the air cavity to be a minimum of
24-1/4”. A larger cavity is fine.
Proximity – Place the subwoofer as close
as possible to the primary listening posi-
tion. Sound dissipates indoors at approxi-
mately 4dB to 6dB each time you double
the distance from the subwoofer to the lis-
tener. Therefore you can expect a 4dB to
6dB increase in output every time you
halve the distance from the subwoofer to
the listener.
Insulation
Lay a batten of fiberglass insulation (e.g.
R-19 un-batted insulation) on top of the
speaker. If you have more than one sub-
woofer in the room, place the same amount
of insulation above each subwoofer. If your
enclosure is smaller than the recommended
1900 cubic inches, try packing more insula-
tion into the space above the speaker. This
effectively increases the enclosure size.
Improving the Stereo Image
Near Satellite
Place the subwoofer(s) as close as possible
to the satellite speakers.
Enclosure Bracing
Insert small pieces of 1x2 or 1x1 scrap
wood as wedges between the ceiling
sheetrock and the floor above if possible.
Do not use too long of a piece as you
could create a bulge in the ceiling surface.
Enclosure Lining
Purchase some subwoofer damping mate-
rial from a car stereo store (there are vari-
9
speaker wire route away as soon as possible.
If construction forces a side by side run for
more than ten feet, install metal conduit or
shielded speaker wire. Low-voltage wires
such as doorbells, intercoms, telephone,
security, or television cannot cause inter-
ference or hum on your speaker wires, so
you can safely run all of them at the same
time, through the same holes, side-by-side.
Installation Fundamentals
Introduction
If you have doubts about whether you are
capable of installing a ceiling mount speak-
er, consult a Niles dealer or professional
installer. They have special tools, tech-
niques, and experience to make the impos-
sible possible. The installer can provide you
with an estimate before any work is done.
Before you drill any holes, mount open
backed J-boxes where the volume controls
and stereo equipment will be. If you are
using the optional hole saving brackets
(CM8 Series New Construction Bracket
kit-FG00656) attach the wings and install
them (See figure 15 and 16).
Running the Speaker Wire in
New Construction
Plan to schedule the speaker wiring after
the electrical wiring is finished. That way
you can avoid wire routes which could
potentially induce hum over the speaker
wire. The basic rules are:
Safety First!
Wear gloves, safety goggles and head pro-
tection when drilling. Avoid nails, they
ruin bits and they can create injury.
• Never run speaker wire through the
same hole as an electrical cable.
Drilling
Use a bit that is large enough for the wires
you plan to run. An auger bit is the pre-
ferred bit for rough-in wiring. It will actual-
ly pull itself through the wood, so that the
drill motor, not you, does most of the
work. You will be drilling a lot of holes, so
this is important.
• Never run speaker wire into the same
J-box as electrical cable.
• Avoid running the speaker wire beside
the electrical cable. Keep it at least three
or four feet away from any electrical
power cable.
Side-by-side wiring is unavoidable in partic-
ular spots in every house, just move the
Always drill the holes in the center of the
stud. If you have to notch the stud or drill
the hole closer than one inch from the edge
of the stud, protect the wire with a nail
plate (See Figure 10).
When drilling holes in ceiling joists drill in
the center of the joists and try to locate the
hole near the end of the joist. DO NOT
drill through a “gluelam” or any load bear-
ing beam without the direction of your
contractor.
Try to line the holes up perfectly, because it
makes pulling the wire much easier.
A good technique is to snap a chalk line
across the face of the studs or against the
Figure 10
10
bottom of the ceiling joists. Then work the ceiling in walls and two-by-six or larger
backward so that you can always see the
holes you have already drilled. Paying care-
ful attention to this will save you a lot of
time later on!
“joists” running horizontally in the ceilings
and floors. In between the studs and the
joists is the space for the wiring and plumb-
ing of your home.
Pulling the Cable
Exterior walls are different. They must insu-
late the house from the heat and cold out-
side, so they are stuffed with insulation. The
national building code requires that the hol-
low wall space in exterior walls be broken
by a horizontal stud placed between the
vertical studs. This “fire blocking” makes it
very difficult to retrofit long lengths of wire.
In some areas of the country the exterior
walls are constructed of solid masonry, and
have no hollow space for speaker wires.
Pull the cable in sections (from the stereo to
the volume control, from the volume con-
trol to the speaker). Start with the longest
sections and use left over wire to complete
the short sections. If you plan to pull many
rooms at the same time through a central
route, walk off the distance to each destina-
tion, add a generous fudge factor for turns
and other obstacles, then cut off each sec-
tion so that you have a bundle of wires you
can pull at once.
Start by examining all the possible routes
you might take to run the speaker wire
from the speaker to the volume control
and back to the stereo. Use a stud sensor
or other device to locate the internal struc-
ture of the ceiling/wall. You want to avoid
as many studs or joists as possible. A typi-
cal speaker wire route would be: from the
speaker location in the ceiling, across the
attic, then down through a top plate (the
horizontal 2x4 or 2x6 laid across the verti-
cal studs) to the volume control location,
back up to the attic, across the attic, and
finally down another wall plate to a j-box
in the wall behind the stereo system itself
(See Figure 11).
Whenever you run the wire further than
four and one half feet from a hole in a stud
or joist (open attic space, going up walls,
etc.), fasten the wire to the joists or studs
using cable clamps or appropriately sized
wire staples. The wire should not have
large sags in it, nor should it be too tight.
Try to protect the wire from being stepped
on in attics or other unfinished crawl
spaces. There are guard strips, raceways
and conduits which can be used to protect
the cable. Consult the local building code
for special requirements in your area.
Concealing Speaker Wire in
Existing Walls
Identify where all of your electrical, phone,
and TV wiring is likely to be and plan to
route around it all. You can accidentally
induce 60Hz hum on your speakers if you
run your speaker wire right beside electri-
cal wire for more than a few feet. Try to
run speaker wire parallel to power cables
at least 3 feet away. To find exactly where
an electrical cable is routed, try inspecting
the inside of the wall by turning off the
breaker for a particular power outlet or
switch, removing the cover plate and
This is actually a fairly simple task if you
restrict your choice of speaker locations
and wire routes to the ceilings or interior
walls of your home. Interior walls in almost
all North American residences are hollow,
so it is easy to flush mount speakers into
them and route new speaker cable around
the house. What you see when you look at
the painted wall board, plaster, or paneling
is only the skin of the wall. Behind the skin
is the skeleton; two-by-four wood or metal
“studs” running vertically from the floor to
11
switch or receptacle, and shining
a penlight into the wall. If you
have access to an attic or base-
ment space you can quickly see
which part of the wall space is
free of obstructions (See Figure
12).
Speaker
Location
When you don’t have access
above or below the wall, try to
estimate the existing wire and
pipe locations from the positions
of electrical outlets and plumbed
fixtures on both sides of the wall.
Take a look at the outside of your
house too, sometimes conduit,
vents or drain pipe will be visible
giving useful information.
Choose the route with the fewest
potential obstacles.
Volume
Control
Location
Stereo
Location
Figure 11
If your house is built on a slab or
you are wiring between two fin-
sible (there are special flat speaker wires
made for under-the-rug wire runs). As a last
resort, heating and air conditioning vents
can be used as wire raceways for plenum
rated wire (check your local building codes,
some municipalities require conduit).
ished floors, look for baseboards which
could be removed and replaced with the
wire behind them. Doorjambs can be
removed and often have enough space for
speaker wire all the way around the door
(See Figure 13).
Sometimes, an under-the-carpet run is pos-
Unobstructed
space for
speaker wiring
Figure 12
12
In traditional wood ceiling joist/drywall
construction you should first cut the hole
for the speaker and utilize the large hole to
auger holes across the ceiling (through the
ceiling joists) for as far as your drill bit will
take you. Sometimes, you will need to use
the “notching” technique to reach areas
your drill bit won’t reach or to turn corners
(e.g. to go down the wall when there is not
an accessible attic). Don’t make an irregu-
lar hole in the drywall. If you carefully cut a
rectangular hatch in the drywall you will
make your patch at the same time you cut
your hole. Notch the bottom of the joists
and run the wire through the notches.
Protect the wire with nail plates. Once
you’ve run your wire replace the hatch you
cut using standard drywall “joint tape” and
“joint compound” to hold the patch in
place, let dry, sand the surface and touch-
up the wall with paint (See Figure14).
Figure 13
The doorjamb has been removed and the speak-
er wire concealed between the wall and the jamb.
Nail plates are installed to protect the wire and
the door jamb is replaced.
Ceiling
Nail plate
Joist
Nail plate
Stud Plate
Wall
Figure 14 Diagram of ceiling speaker cut-out with ceiling joists notched for wire run.
13
breaking them along the scored lines if their
length will interfere with a corner or eaves.
The wings and brackets have centering lines
to simplify the placement of the speaker.
Installation in New
Construction
Screw one side of the assembled bracket
with wings to the joist using one of the
supplied screws. Level the bracket. Screw
the other side of the bracket/wing assem-
bly to the joist. Two screws on each side
makes for a very secure installation.
Secure the wire to the bracket using the
bracket’s wire tie (See Figure 15). The
drywall installers will cut the drywall to
the exact size of the bracket.
Stage One: Before Drywall is Hung
Insulating the Wall Cavity.
If feasible, fill the wall cavity with insulation
at this point.
Mounting The CM8 Series
New Construction Bracket
The hole saving bracket enables a faster
and cleaner final installation of the speaker.
It forces the drywall installer to cut out the
speaker hole for you and provides wire ties
for the speaker wire, reducing the risks of
accidental loss or movement of the wire. In
addition, it enables you to align your speak-
ers with other ceiling fixtures with great
accuracy since you can really see exactly
where the speaker will be.
Concealing Speaker Wire for
a Future Installation
Attach the speaker wire in a loop between
the ceiling joists and carefully mark the
exact location of the wire on a set of plans
Ask the general contractor to inform the
drywall installers that the speaker wire
loops are concealed for future installation.
(See Figure 16).
To install the bracket, first attach the
™
QuickSnap new construction wings to the
bracket by snapping them into the sides of
the bracket. The wings can be shortened by
Figure 15
Figure 16
The optional hole saving brackets are installed
and the speaker wire is attached to the bracket.
A loop of wire is attached to the joists marking
the location of the speaker.
14
Installation in
Existing Construction
IMPORTANT: Before you cut into any
wall, review the sections on running
wire and speaker placement.
1. When determining the location of the
speaker cutout keep in mind that the
mounting dogs will extend 3/4” beyond
the cutout. Make sure that you do not
place the edge of the cutout directly next
to a ceiling joist. Locate the joists using a
stud sensor or hand-knocking.
Figure 17
Feeling for obstructions
behind the ceiling surface.
5. If you are cutting into drywall use a
sheetrock or keyhole saw. Cut the hole
with the saw at a 45° angle. That way,
the drywall section can be replaced
cleanly if there is an undetected obstruc-
tion behind the ceiling surface. BE VERY
CAREFUL NOT TO SAW THROUGH
EXISTING WIRES, PIPES, OR STRUC-
TURE. IF YOU FEEL ANY EXTRA RESIS-
TANCE AS YOU ARE CUTTING, STOP.
2. Once you have determined a possible
position for the cutout, drill a 1/8” pilot
hole barely through the wallboard or
dry wall (1/2” to 5/8” deep in most
homes) in the center of your proposed
speaker location. BE VERY CAREFUL
NOT TO DRILL THROUGH EXISTING
WIRES, PIPES, OR STRUCTURE. IF
YOU FEEL ANY EXTRA RESISTANCE
AS YOU ARE DRILLING, STOP.
6. If you are cutting into a plaster ceiling,
use masking tape to outline your pen-
ciled circle and use a razor to score the
plaster down to the lath beneath. Then
use a chisel to remove all of the plaster
within the taped outline. To actually cut
the lath, two methods are used profes-
sionally; sawing with a metal cutting
blade on a sabre saw is the quickest
and the riskiest. Sawing a lath with a
sabre saw can easily vibrate plaster off
the ceiling in a completely distant loca-
tion creating more patch work. If you
have the patience, use a pair of tin snips
to slowly nip away at the lath instead.
There is no risk with this method, it is
just time consuming.
3. Cut a foot long piece of coat hanger.
Bend the wire (creating a right angle)
leaving 5-1/2” at one end (this allows
for the extra width of the mounting
dogs). Poke the “L-shaped” wire into
the pilot hole and turn it in a complete
circle and move it into the ceiling cavi-
ty to make sure you have approximately
3-3/4” of depth. If the coat hanger
movement is obstructed by anything, fill
the hole(s) with spackle and try another
location. (See Figure 17).
4. If the coat hanger moves freely in a
complete circle, hold the supplied tem-
plate up to the ceiling surface. Outline
the circular cutout on the ceiling sur-
face with a pencil. Drill a starting point
with a 1/4” drill bit.
15
Final Installation in New
or Existing Construction
1. If it is possible to lay a batt of insulation
into the ceiling cavity, do so. Remember
to use equal amounts of insulation for
each speaker.
Figure 18
Tightening the
mounting “dogs”.
2. Separate the speaker wire so that at least
two inches of each conductor are free.
NOTE: The screws will be easier to turn if
you “prime” them first. Before installing each
speaker, turn the screws in and then turn
them back out to their original positions.
3. Open the no-strip terminal by applying
pressure to the red and black levers until
an audible “click” is heard.
4. Insert one unstripped wire fully into the
black and one into the red terminal. Pay
attention to the markings on the wire.
Each speaker must be connected to the
amplifier in the same way. If unsure,
see section “Speaker Phase” located on
the following page. Squeeze the red
and black levers until they click signify-
ing that they have locked into the wire.
8. Setting the High Pass Filter
When the “SAT” filter is in the CUT
position, all of the bass energy will be
produced via the CM8SW. When the
switch is in the FULL position, both the
satellite speakers and the CM8SW will
reproduce the bass signal. Typically,
satellites with woofers that are 5-3/8” or
smaller will sound best with the filter
on. Listen to a loud and well recorded
bass passage to evaluate.
5. Insert the no strip terminal into the
corresponding socket on the rear of the
speaker. Push it down until it locks in
place. The terminal will only fit in the
socket in one direction. If the terminal
does not properly seat, reverse the terminal
9. Setting the Subwoofer Low Pass Filter
With the “SUB” switch in the 100Hz
position, the CM8SW will only repro-
duce bass below one hundred cycles.
When the switch is in the 140Hz posi-
tion, the CM8SW will reproduce bass
below 140 cycles. Depending on the
size of the room, the type of satellite
speaker and the subwoofer position,
you will prefer one setting to the other.
Listen to a loud and well recorded bass
passage to evaluate.
6. Connect the wire which runs to the
satellite speakers to the left and right
output terminals. Pay attention to the
markings on the wire.
7. There are four clamps or mounting
“dogs” which hold each speaker in
place. The dogs are tightened via four
front-baffle screws. To install the speaker,
first rotate the dogs inward. Insert the
speaker into the cutout and tighten the
dogs by turning the screws clockwise.
DO NOT OVER TIGHTEN THESE
SCREWS. Over-tightening the clamps
may make the grille difficult to install.
(SeeFigure18).
10.Install the grille into the speaker. The
grilles should fit snugly. If you have diffi-
culty fitting them in, try loosening the
mounting dog screws slightly (excessive
tightening can distort the shape of the
frame holding the grille in place).
16
great deal louder, that was the problem.
If bass sound was reduced return the
connections to their original state.
Painting the Speakers
All models may be painted. The plastic will
readily accept most paints.
2. Subwoofer /Satellite Relative Phasing
An acoustically out-of-phase sat/sub
combination works against each other
and the sound of the overall system will
be lacking in bass. This might be
because of the position of the subwoofer
rather than an error in wiring. Try revers-
ing the phase of both the left and the
right outputs of the subwoofer. Make
sure you evaluate (listen) from the prima-
ry listening position.
The speakers must be masked prior to
painting them. The inside circular portion
of the hole template can be used as a
paint mask. Remove the outside portion of
the template by gently pulling along the
perforation. Affix the mask to the front of
the speaker by friction-fitting the mask into
the bezel.
The grilles should be painted before they
are installed. For all models, the best
results will be obtained by using a spray
gun or airless sprayer, thinning the paint
(prevents clogging of grille holes), and by
applying several light coats instead of one
heavy one.
3. Satellite Left-Right Phase Reversal
If the right satellite is reversed in phase
from the connections on the left satellite,
you will hear reduced bass and a
“phasey” diffused vocal image. If you
suspect the sound is not right and you
cannot see any markings on the wire, try
this simple test:
Speaker/Subwoofer Phase
Speaker wire has two conductors. One
conductor is attached to the negative (–)
terminals and one conductor is attached to
the positive (+) terminals of both your
speaker and your amplifier. Usually, the
wire is marked for your convenience.
There are different ways wires are marked:
a stripe on one wire, a ribbed area of one
conductor you can only feel, different col-
ors of metal wire on each conductor, or
there might be a fabric strand or string
wound into one of the conductors. Of
course, there are some wires which appear
completely identical. Be careful, or you
might make a mistake.
a. Stand half way between the two satellite
speakers.
b. Play some vocal music with the amplifier
or radio set to Mono.
c. Listen to the apparent placement of the
vocals.
d. Turn off the amplifier and reverse one of
the connections on the subwoofer.
e. Repeat the listening test with the same
setting of the volume control. When
the sound has a richer bass, is slightly
louder and the vocal image is
“focused” the satellites are working
together or “in-phase”.
If you make a mistake, there are three pos-
sibilities:
1. Subwoofer Input Phase Reversal
The Left Input of the Subwoofer is out of
Phase with the Right Input. If this is the
case, you will hear almost no output out
of the subwoofer when playing a loud
bass passage. Try reversing one of the
subwoofer inputs. If the sound gets a
17
Operation
Congratulations
A concealed CM8SW subwoofer installation
frees you to use your tone controls, play the sys-
tem loudly and enjoy deep extended bass, even
if your satellite speakers are small. When used
with satellite speakers that have substantial bass
of their own, the CM8SW tightens the deep
tones and augments the bass musically.
Listening at Higher Volumes
It requires more power to achieve a reasonable
volume of sound in a large room than it does in
a small room. It is possible (even if you are not a
teenager) to turn the volume so high that the
amplifier runs out of power. This creates “clip-
ping” distortion. If you are using an extremely
powerful amplifier it may be possible to hear
clicking or buzzing sounds from the subwoofer
as it tries to reproduce too loud a sound. If you
hear these sounds turn the volume down.
More typically you will hear clipping distortion
through your satellite speakers. Clipping distor-
tion makes treble sound very harsh and unmusi-
cal. When you hear harsh sounding treble from
any good speaker, turn the volume down
immediately! Those harsh sounds are masking
some much more powerful ultra-high-frequency
sound spikes which will quickly damage any
fine loudspeaker. You are much less likely to
damage a speaker with a large amplifier
because it will be very loud indeed before it
produces any clipping distortion.
Cleaning
You can clean the speaker with a dampened
soft cloth or paper towel. If the speaker is
mounted high up on the ceiling, use a broom to
gently brush it off.
18
Specifications
CM8SW
Driver Complement
8” dual voice-coil injection molded TCC (Talc, carbon and ceramic-filled) woofer with
butyl rubber surround
Design Principle
Infinite baffle for large and varying air volumes
Recommended Amplifier Power
10 to 150 watts per channel
Impedance
8 ohm
Frequency Response
35 – 140Hz, +/- 3dB
Sensitivity
90 dB for 2.83 volts of pink noise, measured at 1 meter on axis
Overall Exterior Frame Dimensions
10-5/8" diameter
Depth Behind Wall
4" (based on 1/2" drywall)
Wall Cut-Out Dimensions
9-1/2" diameter
Connections
Dual patented two-piece, no-strip speaker wire terminal, accommodates.12-18 gauge
19
WARRANTY REGISTRATION CARD
Model Purchased__________________________________________________________________________________
Serial Number___________________________________________________________________________________
Date Purchased (month/day/year)_________________________________________________________________
Dealer Name and Location________________________________________________________________________
__________________________________________________________________________________________________
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K Ms.
Name____________________________________________________________________________________________
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_________________________________________________________________________________________________
City_________________________________________________________State______________Zip______________
Telephone (___________)___________________________________________________________________________
Please take a moment to fill out our warranty registration card. The information helps us to
get to know you better and develop the products you want
Age:
Musical tastes:
What magazines do
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Do you. . .?
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Under 25
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(Please check all that
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how many square feet?
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product?
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Over $99,999
Are you interested in
receiving literature on
other Niles products?
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Myself
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about Niles?
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enced the purchase of
your Niles product?
Are there products/
capabilities that you
would like to see
introduced?
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Occupation:
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Ease of Use
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Warranty
PLEASE FILL OUT THE
WARRANTY REGISTRATION
CARD ON THE REVERSE SIDE,
DETACH, AND MAIL TO:
Niles Audio Corporation
Warranty Registration Dept.
P.O. Box 160818
Miami, Florida 33116-0818
®
Limited Warranty
Niles Audio Corporation ("NILES") warrants its loudspeaker products to the original purchaser
to be free of manufacturing defects in material and workmanship for a period of five years
from date of purchase.
This Warranty is subject to the following additional conditions and limitations. The Warranty
is void and inapplicable if NILES deems that the product has been used or handled other than
in accordance with the instructions provided by the manufacturer, including but not limited to
damage caused by accident, mishandling, improper installation, abuse, negligence, or normal
wear and tear, or any defect caused by repair to the product by anyone other than NILES or an
authorized NILES dealer.
To obtain warranty service, take the unit to the nearest authorized NILES dealer, who will test
the product and if necessary, forward it to NILES for service. If there are no authorized NILES
dealers in your area, you must write to NILES and include your name, address, model and
serial number of your unit, along with a brief description of the problem. A factory Return
Authorization Number will be sent to you. DO NOT RETURN ANY UNIT WITHOUT FIRST
RECEIVING WRITTEN AUTHORIZATION AND SHIPPING INSTRUCTIONS FROM NILES.
If the above conditions are met, the purchaser's sole remedy shall be to return the product to
NILES, in which case NILES will repair or replace, at its sole option, the defective product
without charge for parts or labor. NILES will return a unit repaired or replaced under warranty
by shipping same by its usual shipping method from the factory (only) at its expense within the
United States of America. THERE ARE NO OTHER WARRANTIES, INCLUDING WITHOUT
LIMITATION, EITHER EXPRESS OR IMPLIED WARRANTIES OF MERCHANTABILITY OR FIT-
NESS FOR A PARTICULAR PURPOSE, WITH RESPECT TO THE PRODUCT.
REPAIR OR REPLACEMENT AS PROVIDED UNDER THIS WARRANTY IS THE EXCLUSIVE
REMEDY OF THE CONSUMER/PURCHASER. NILES SHALL NOT BE RESPONSIBLE FOR
ANY INCIDENTAL OR CONSEQUENTIAL DAMAGES EXCEPT TO THE EXTENT PROVIDED
(OR PROHIBITED) BY APPLICABLE LAW.
Some states do not allow the exclusion or limitation of incidental or consequential damages,
so the above limitation may not apply to you. This warranty gives you specific legal rights, and
you may also have other rights which vary from state to state.
For the name of your nearest authorized NILES dealer contact:
NILES AUDIO CORPORATION
P.O. BOX 160818, Miami, Florida 33116-0818.
Please fill in your product information and retain for your records.
CM8SW
Model____________________________________________________________________________________
Serial No._________________________________________________________________________________
Purchase Date_____________________________________________________________________________
22
Niles Audio
Corporation
12331 S.W. 130 Street
Miami, Florida 33186
Tel: (305) 238-4373
Fax: (305) 238-0185
© 2004 Niles Audio Corporation. All Rights Reserved. Niles, the Niles logo, and Blending
High Fidelity and Architecture are registered trademarks of Niles Audio Corporation.
MicroPerf is a trademark of Niles Audio Corporation. All other trademarks are the property
of their respective owners. Because we constantly strive to improve our products, Niles
reserves the right to change product specifications without notice. The technical and
other information contained herein is not intended to set forth all technical and other
specifications of Niles products. Additional information can be obtained on-line. Printed in
China. DS00292ACN
Printed in China
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