TKOKO CH-902H User manual

Public address systems
& Commercial sound systems
CH-902H
Ceiling Speaker
www.t-koko.com

CH-902H
PREMIUMCEILINGSPEAKER
INSTALLATION AND OPERATION MANUAL
IMPORTANT SAFETY INFORMATION
1、Save the carton packing material even if the equipment has

arrived in good condition. Should you ever need to ship the unit.
Use only the original factory packing.
2、Read all documentation before operating your
equipment .Retain all documentation for future
reference.
3、Follow all instructions printed on unit chassis for proper
operation.
4、Do not spill water or other liquids into or on the unit ,or
operate the unit while standing in liquid.
5、Make sure power outlets conform to the power requirements
listed on the back of the unit.
6、Do not use the unit if the electricalpower cord is frayed or
broken.The power supply cords should be routed so that they
are not likely to be wallked on or pinched by items placed upon
or against them,paying particular attention to cords and
plugs,convenience receptacles,and the point where they exit
from the appliance.
7、Always operate the unit with the AC ground were connected
to the electrical system ground.Precautions should be taken so
that the means of grounding of a piece of equipment is not
defeated.
8、Mains voltage must be correct and the same as that printed
on the rear of the unit.Damage caused by connection to
improperAC voltage is not covered by any warranty.
9、Have gain controls on amplifiers turned down during
power-up to prevent speaker damage if there are high signal
levels at the inputs
10、Power down﹠disconnect units from mains voltage before
making connections.
11、Never hold a power switch in the “ON” position if it won’t
stay there itself!
12、Do not use the unit near stoves, heat registers,radiators,or
other heat producing devices

13、Do not block fan intake or exhaust ports. Do not operate
equipment on a surface or in an
Environment which may impede the normal flow of air around
the unit,such as a bed,rug.
Weathersheet,carpet,or completely enclosed rack.. If the unit is
used in an extremely dusty or smoky envronment,the unit
should be periodically “blown free” of foerign matter.
14、Do not remove the cover.Removing the cover will expose
you to potentially dangerous voltages.There are no user
serviceable parts inside.
15、Do not drive the inputs with a signal level greater than that
required to drive equipment to full output.
16、Do not connect the inputs/outputs of amplifiers or consoles
to any other voltage source,such as a battery,mains source,or
power supply,regardless of whether the amplifier or console is
turned on or off.
17、Do not run the output of any amplifier channel back into
another channel’s input.Do not parallel-or series-connect an
amplifier output with any other amplifier output.Australian
Monitor Inc is not responsible for damage to loudspeakers for
any reason.
18、Do not ground any red (“hot”) terminal. Never connect a
“hot” (red) output to ground or to another “hor” (red) output!
19、Non-use periods .The power cord of equipment should be
unplugged from the outlet when left unused for a long period of
time.
20、Service Information Equipment should be serviced by
qualified service personnel when:
A、The power supply cord or the plug has been damage.
B、Objects have fallen,or liquid has been spilled into the
equipment
C、The equipment has been exposed to rain.
D、The equipment does not appear to operate normally,or

exhibits a marked change in performance
E、The equipment has been dropped,or the enclosure damaged.
THIS SAFETY INFORMATION IS OF AGENERAL NATURE AND MAY BE SUPERSEDED BY
INSTRUCTIONS CONTAINED WITHIN THIS MANUAL
INTRODUCTION AND CONTENTS
Thank you for choosing the premium
ceiling speaker.
The CH-902H has been developed
using innovative design and
materials to meet the demanding
constraints of high quality
foreground/background sound
reproduction from a ceiling-mouted
speaker.Featuring a sealed metal
back box,the 6.5” woofer gives
superior bass response to a
conventional ceiling speaker
The 3/4” titanium tweeter is
horn-loaded to maximize
high-frequency coverage.
Rated at 60 watts,with 70/100V
tappings at 7.5,15,30 and 60 watts,
the CH-902H also features a 16 ohm
transformer bypass setting.
Included mounting hardware give
ease of installation combined with
safety.
FEATURES 2
INSTALLATION 3
SPECIFICATIONS 6

RISK ELECTRIC SHOCK
DONOTOPEN
CAUTION：TO REDUCE THE RISK OF ELECTRIC SHOCK
DONOTREMOVECOVER （OR BACK）
NO USER-SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
WARNING！
TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK
DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE
This symbol is intend to ablert the user to the presence of
uninsulated “dangerous voltage” within the product’s
enclosure that may be of sufficient magnitude to
constitute a risk of electric shock to persons.
This symbol is intended to alert the user to the presence
of important operation and maintenance (servicing)
instructions in the literature accompanying the appliance.
To prevent electric shock do not use this (polarised) plug

with an extension cord,receptacle or other outlet unless
the blades can be fully inserted to prevent blade exposure .
To prevent electric shock, match wide blade of plug to
wide slot, fully insert.
FEATURES
SteelBackcan
TapSelector AttachmentScrews
LoudspeakerDriver
Seconday Support Tab
Rotating
MountingTabs

Perforated
Press-In Grille
INSTALLATION
The CH-902H and suppplied mounting hardware has been
designed for easy installation while maintaning a high standard
of safety.The whole installation process can be completed from
below the ceiling,if necessary,although working from both sides
of a ceiling title is faster.To ensure a relliable installation,please
follow these steps carefully.
1、Preparation
Determine the correct mounting hardware for your paticular
ceiling construction (see diagram 2).
The C-Bracket spreads the clamping force of the mounting
tabs,and strenghens the edge of the hole.The C-Bracket may be
used without the title rails.
The Tile Rails spread the weight of the speaker across the
ceiling.If the ceilling tile should fall out or breal,the Tile Rails
will catch onto the ceiling girl and prevent the speaker from
falling.
NOTE:Due to the wide response of the CH-902H,the
low frequency vibrations generated may cause buzzingor
the edges of the ceiling tiles may be required.
2、Cut hole

Determine the speaker position,taking into account any
obstructions in the ceiling space.
Note that clearance of 185mm above the lower face of the
ceiling is required.
Cutout diameter is 223mm.The C-Bracket can be used as a
template.
SPECIFICATIONS
Model CH-902H
Low-frequency driver 160mm diameter woofer
High-frequency driver 19mm diameter horn loaded tweeter
Power tappings/Impedance W(100V) W(70V)
- 60
60 30
30 15
15 7.5
Frequency response 65-20kHz
Driver power 30Wrms 60Wpeak
Sensitivity 92dB(1W/1m)
Weight 3.7kg
Cutout hole diameter 223mm

INSTALLATION
6、Selcet power
Using a flat-bladed screwdriver,rotate
theTap Selector so the correct power
setting is adjacent to the arrow.Note
that there areseparate 70V and 100V
scales,depending on the amplifier
being used(see diagram7) The tans
formermay also be by passed by
selecting thePS position.It may be
desirable to leavethe grilles off until
commissioning is completed if
adjustments are likely to be needed.
CAUTION:To avoid distoration or equipment
damage,carefully consider the power ratings of
both amplifiers and speakers.
Only 2 speakers at 60W will fully load a 120W
amplifier,but note that each will be producing
more than 106dB direct Sound Pressure Level
at the listener when installed in a 3m
ceiling!Dropping to the 15W tap allows 8
speakers to be driven by the same amplifier,
each producing 100dB SPL.

If 60W @ 70V is selected,but 100V line
amplifier is connected,the speaker will draw
up to 120W and damage is likely
.
INSTALLATION
7、Fit grille
Carefully insert the perforated grille into the speaker body and
press in firmly.
To prevent the grille from vibrating loose,ensure that it is fully
pressed in.