Quest Engineering QSA Series User manual

QSA 200i
ACTIVE LOUDSPEAKER
user manual

QSA200i
User Manual
QSA200i
Active Loudspeaker
User Manual
2
QSA200i
User Manual
User Manual
QSA200i
Active Loudspeaker
3
Attention
Before connecting or operating your new
Quest Engineering speaker, please study the
accompanying instruction manual paying particular
attention to the operating precautions and wiring
procedure.
Quest Engineering will not assume responsibility for
incorrect installation or operation of this product.
Contents
Safety 03
Installation 04
Connections 05
Glossary 06
Operating Tips 07
Troubleshooting 08
Inputs and Outputs 09
Specifications 10
Accessories 11
Register Your Product
Thank you for choosing Quest. Please take the time
to complete your procuct registration card which is
included with the packaging. Registering your Quest
Engineering product will:
Very important
Before using your speaker check to make sure
that the selection of the power supply voltage
(115/230 Volts) is set correctly for your country. An
incorrect setting can lead to severe damage to your
new powered speaker on activation. If you are not
certain that it is set correctly, check with your Quest
Engineering dealer.
• CONFIRM YOUR WARRANTY
• REGISTER YOUR PRODUCT
• PROTECT YOUR NEW PRODUCT
Flying and installation of this
speaker cabinet must be carried out
by suitably qualied personnel
following the approved safety
standards.
Do not attempt to clean any plastic
parts with solvents or petrochemical
based cleaners.
The power voltages inside this
device are high and could cause
serious injury or death if touched
while the power is connected. Do
not open the amplier case as there
are no user serviceable parts inside.
Safety Precautions
Do not expose the speaker cabinet
to direct precipitation or stand in
water. Liquid getting into the box
will risk a short circuit and will be
hazardous.
Do not stack the speaker cabinet
in a manner that could cause injury
should a cabinet become dislodged.
Do not place sources of heat on the
speaker cabinet such as lighting
equipment or smoke machines.
CONTENTS SAFETY

QSA200i
User Manual
QSA200i
Active Loudspeaker
User Manual
4
QSA200i
User Manual
User Manual
QSA200i
Active Loudspeaker
5
Description
The QSA speaker range is a two-way active bass
reex design suitable for mobile or installation
use. The power ampliers are multiple integrated
A-B class design capable of high power yet light
in weight. There are separate ampliers for the
high and low frequency drivers and both are
protected by an “analogue engine” processor
that monitors peak and RMS power and makes
EQ and time alignment corrections.
The operation of these devices will not affect
audio quality due to their advanced design.
Audio processors will control and protect the
system to a reasonable degree but are not a
substitute for sensible operation. The system will
sound at its best when mixers and other signal
processors in the audio chain are not being over
driven into distortion.
Full range or
mid-high applications
The design characteristics make the QSA series
suitable for both full-range use or as the high-mid
component of a multi-way system with sub-bass
enhancement. Coupled with a Quest Engineering
sub-bass system, the QSA200i will provide very
good full bandwidth audio coverage at medium
to high sound pressure levels.
Installation
Temporary installation is possible with the 35mm
stand mounting in the base of the enclosure.
Fold-back installation is possible with the
addition of the oor stand/wall bracket optional
accessory, (WBFS8).
Flying installation
Two M6 thread inserts are located on the top and
one under the QSA series enclosures. These are
intended to be used with the designated wall
mount bracket.
QSA Series flying accessories
See page 11 for list of accessories.
Safe installation procedures
• The QSA200i should be installed using the
WBFS bracket and secured by both top and
bottom nut inserts.
• The QSA200i can be hung with “I” bolts
attached to the top 8mm insert bolts.
• Under no circumstances attach the box with less
than two of the threaded inserts (see figure a)
• The speaker box must not be installed in a manner
where the weight is not equally distributed between
two insert points.
• One pair of threaded inserts may only carry
the weight of one box. Therefore multiple box
rigging from one pair of insert points should not be
attempted. (see figure b)
• Do not locate boxes near sources of moisture or
where water can enter the box. (see figure c)
Quest QSA200i Series: Rear Panel Description
INSTALLATION CONNECTION
1. Power amp active indicator.
2. Clip/limit indicator. If this LED illuminates for
more than an occasional ash, turn down the
mixer output. If you need more volume, set up
more speaker boxes.
3. Microphone balanced input volume control.
4. Line level volume control.
5. Microphone level (low impedance) input.
6. Line level balanced input.
(To mixer or other +4 dB or less line level)
7. Line out. This is a through output of the
same level as the line input.
8. Loop/Mix Output mix selector signal in/out
through
9. Power on/off switch.
10. Power supply input. Make sure that the
voltage selector is set for your Country’s
correct voltage.
11. Protection fuse. Use only fuses of the correct
Amp rating. If it blows more than once, return
the box to a Quest Engineering service centre.
1 2
3
4
5
6
7
8
10
11
9
(b)
(c)
(a)

QSA200i
User Manual
QSA200i
Active Loudspeaker
User Manual
6
QSA200i
User Manual
User Manual
QSA200i
Active Loudspeaker
7
GLOSSARY OPERATING TIPS
PRE-AMPLIFIER: That part of the signal chain
where a signal from a microphone, turntable, CD
player or other signal source is rst amplied.
This will normally be at the input of a mixer and is
necessary to boost the signal enough to be then
mixed and amplied by a power amplier.
POWER AMPLIFIER: Boosts the signal enough
so it can be reproduced by a loudspeaker.
ELECTRONIC CROSS OVER: Splits up the
full range audio signal to separate high and low
frequencies. This is done to send low frequencies
to the bass speaker and high frequencies to the
tweeter or high frequency horn driver.
SELF-POWERED: Refers to a speaker or a mixer
that contains a power amplier.
CLIPPING: Distortion that is caused by having too
much signal at an input causing the amplier to
overload. It is called clipping because it will cause
a smooth wave to be cut off at the peak of the
wave. In other words, “clipped”
GAIN STRUCTURE: The relationship of input
levels to output levels in a signal chain. An
example of incorrect gain structure is when a
mixer is turned up to the point of audible distortion
(red lights ashing serious overload), and the
power ampliers are turned down and running at
only 30% power.
COMPRESSION: An electronic device that
reduces the dynamic range. In other words,
makes the loud parts of the music less loud and
the quiet parts appear louder. When used correctly
it can make live music sound more even and
balanced.
LIMITER: An electronic device that will prevent
the signal from exceeding a set level of output.
Normally used as a system protection to prevent it
from being over driven by excessive input.
PHASE (IN or OUT OF PHASE): This really means
speaker polarity. The input terminals of a normal
loudspeaker have a + positive red terminal and a
- negative black terminal. In the case where there
are two speakers operating as a pair or together
as an array, will need to all be wired the same way.
If a speaker connecter, speaker lead or speaker
box is wired in reverse to a box near it, loss of
performance will result. This may be in the form
of lost low frequency response. In this case you
will see the bass speaker working hard but as you
move away from the box, the bass frequencies will
seem to “disappear”.
Check that your speaker leads do not have one
lead wired in reverse at one end and that the
speaker boxes are all wired correctly internally.
This can happen when a speaker box has been
repaired and then not assembled with the wiring
connected correctly.
Glossary
Basic professional audio practice and hints for best results
Operating Tips
To avoid overloading the pre-amp inputs, always
operate the master volume at a high level and
control the volume from the input volume.
The ideal situation is to have all the components
of the audio chain operating at the same
operational range.
Do not run the system with the mixer “peaking
in the red” while the box is turned down.
Also do not operate the system with the input
peaking (red overload light on or ashing) and the
master volume turned down.
Red lights ashing on a mixer indicate distortion.
If you have a mixer with the facility to show you
the input level on a meter, for example then you
push a CUE/PFL button, set the input level to
below the level of the red end of the LED ramp.
If you run the row of red lights to the end of the
ramp you will cause distortion at the very start
of the pre amplier stage of the mixer. At this
point it will sound dirty and “zzy” regardless of
how good the rest of your sound system is. The
rest of the system will be reproducing a distorted
sound. If you need more volume, turn down the
input signal so it is out of the red and turn up the
output of the mixer.
Input
Signal
Electronic
xover
Low Freq.
Amp
Low Freq.
Drive
Hi Freq.
Drive
Hi Freq.
Amp
Clipping
Clipping
Compressor
Threshold
1:1
3:1
Output Level
10
10
Limiter
Threshold
Output Level
10
10
1:1
0:1
MIXER
MIXER
MIXER
AMP
AMP
AMP
10
1
12
5
10
1
5
100
5
CLIP/LIMIT
10
1
12
5
10
1
5
100
5
CLIP/LIMIT
10
1
12
5
10
1
5
100
5
CLIP/LIMIT

QSA200i
User Manual
QSA200i
Active Loudspeaker
User Manual
8
QSA200i
User Manual
User Manual
QSA200i
Active Loudspeaker
9
TROUBLESHOOTING INPUTS/OUTPUTS
Getting rid of unwanted noises is a study in
itself. Most of the noise, (apart from undesirable
program) will fall into three categories.
Troubleshooting
Buzzes and noises in the sound system
(3) BUZZ: Sometimes you can experience a hum
and buzz together. A buzz is almost always a
problem with the “earthing” of the system. It will
often occur when you have the system powered
from sperate power outlets in the same building
or audio and lighting sharing a common power
circuit.
Even when the audio and lighting systems are
powered from separate sources, there can still
be a common earth between them. For example,
a smoke machine may be powered from the
lighting system, yet the trigger mechanism could
be connected to the audio system through the
audio multi-core/snake.
An earth connection between the audio and
lighting will now exist and a buzz could be
amplied in the audio system. The simple
solution is to power your audio circuit and
everything connected to it from the same source.
If the buzz persists, check your signal cables,
one may have an earth/shield disconnected.
A cheap but possibly life saving investment is a
domestic power tester to check that the power
supply sockets are correctly wired. Faulty or
incorrectly wired power is a booby trap that is
more common than you think.
It is wise to avoid switching on or off devices
in the signal path while the speaker system is
powered and turned up. Otherwise loud clicks
and bangs could result. When shutting down the
system, always turn the speakers off rst. This
is to prevent the speaker amplifying the sound
of the other equipment in the chain being shut
down. The reverse is true when powering up.
Mixers and effects on rst, power ampliers or
powered speakers on last.
(1) WHITE NOISE: This is the hiss that suggests
that the gain structure is set incorrectly.
Something in the signal chain is boosting too
much or an input is set too sensitive. If your
equipment has gain switches on it, set them all
the same. If the switch is labelled +4dB, set them
all to that gure. If one piece of equipment seems
to be overloading, set them all to -10/-20dB and
be prepared to boost the input level of the QSA
input. The last unit in the chain should be set
to +4 dB at the output stage if possible when
connected to the line level input of the QSA
series input.
(2) LOW FREQUENCY HUM: This is often
caused by noise from the power leads being
picked up by the audio signal cables. The
preferred solution is to connect up your system
with “balanced” XLR microphone cables.
Especially if you are running the cables a long
distance, (more than 5Mtrs /15 Ft). The other
solution is to make sure that your audio cables
are as far from power cables as possible.
Inputs and outputs
The inputs can accept both XLR and phono
connectors. If you are connecting multiple boxes
together is unprofessional practice to use a
mixture of both phono and XLR types of leads.
Use one or the other otherwise an out of phase
situation can result.
Tips on “flying clusters”
When very high output or broad coverage is
required, it is common practice to assemble an
array of speakers together.
In a own horizontal array of high/mid congured
speakers, best results are obtained by angling
the boxes apart slightly at the front of the array
while the rear of the boxes must be together on
the same vertical plane.
The purpose is to minimise phase shift and
interference effects between the boxes. If two
boxes are directing acoustic energy into the
same coverage area, loss of smooth frequency
response will result. This is called “lobing” as
“ngers” of both frequency peaks and dips
spread out across the coverage area, especially
at the area where the signal from the overlapping
coverage converges.
QSA 200i Array

QSA200i
User Manu al
QSA200i
Active Loudspeaker
User Manual
10
QSA200i
User Manual
User Manual
QSA200i
Active Loudspeaker
11
cations at any time and
won’t be held responsible for any typographic errors in this publication.
SPECIFICATIONS
ACCESSORIES
Quest QSA 200i: Specifications
FrequencyRange -3dB 70 - 20 kHz
HF Coverage Angle are
Max SPL123 dB (C weighted)
Amplifier Power HF 50 Watts LF 100 Watts
Transducer 1x ¾-inch Compression driver
1x 8-inch Long coil bass driver
Enclosure Injection molded plastic
Protective Grill Perforated steel acoustic foam covering
Input Connections 2 channels XLR in XLR through out
Dimensions250mm (10") x 240mm (9.5") x 430mm (17")
Net Weight8 kg
Installation Options 365mm pole mount
oor stand
WBU8i wall bracket through 6mm insert bolts
Product features
·Two-channel independent XLR mic/line inputs
·XLR line our with mix add function
·Long lasting heavy-duty Quest speaker
components
·Uniform high frequency coverage with custom
designed rotating HF wave-guide
·Great sonic performance through analogue
engine signal processing
ers
·Steel protective full front grill
Accessories Essentials for your QSA
QB200i Protective nylon speakbag
QSSALHeavyduty aluminium speaker stand withcarrybag
WBU8I U wall bracket to suit QSA200i & QS/150
WBFJ8 Wall bracket / foldback adaptor
WBU8I
QB200i &QSSALWBFJ8
WBFJ8 with QSA200i attached

www.questaudio.net