Quested S8 User Manual

S8

S8

User Manual

Quested Mon itorin g Sy stems Ltd.,

Un it s 6-8 King sg ate,

Heathpark Ind ustrial Estate,

HO NITON,

Devon EX14 1Y G

En gland

Tel: ++(0)140 4.4 15 00 Fax: ++(0)1404 .44 660

2

ww w.quested.com

CONTENTS

1 Introduction 3

1.1 Class A-B Amplifiers 3

2 Safety Considerations 3

2.1 General 3

2.2 Hearing damage 4

3 Unpacking 4

4 Installation 4

4.1 Positioning 4

4.2 Grill 5

4.3 Aligning the speakers 5

4.4 Wall mounting 6

4.5 Electrical Connection 7

4.5.1 Safety Earthing 7

4.5.2 Voltage Setting 7

4.5.3 Fuse Set ting 8

4.6 Audio connections 8

5 Operational Considerations 10

5.1 Mains On-Off Switching 10

5.2 Thermal 10

5.3 Front panel indicators 10

5.4 Signal level 10

5.5 Contour selectors 10

6 Tech nical Specification 11

7 Line Drawing 1 2

8 Guarantee 12

9 Appendix 13

9.1 Accessories 13

9.2 Spares 13

9.3 Driver replacement 13

3

1 INTRODUCTION

Th ank you for purchasing this Quested monitor and you can be cert ain that you have purchased one

of the finest monitors in the world. If you take time and care in positioning and aligning the system,
you will appreciate why Quested monitors have a reputation for faithful reproduction covering t he
entire audible spectrum. They are professional monit ors, and therefore are not designed to flatter but
faithfully reproduce. Please take care to maintain th e system and it will give you many years of
service.
You will also be assured the best possible performance and long-term reliability of your system.

Please read this manual, which we have kept as co ncise as possible, it really will help you and covers
Impo rtant safety considerations.

The S8 is a self-powered, 2-way active monitor. Its 370 watts of linear class A-B amplification make
it a powerful choice. Typical applicatio ns include near to mid-field monitoring for recording/mixing,
post production suites, broadcast and surround sound. T he high power output enables the monitors to
be
used where high monitoring levels are required.

Although the bandwidth of the S8 is adequate for most situations, the low end performance can be
further extended by combining it with an S B s er i es sub bass. The two products make an ideal
combination and ex tend the frequency response down to 20 Hz.

1.1 Class A-B amplifiers

The S8 use’s class A-B amplification, as with a lot of class A-B amplifiers they will only reach there
peak sonic performance aft er a given warm up period. We have taken this into co nsideration when
designing the S8. During this warm up period the front mounted LED will flash green. When the
amplifier has warmed up the LED will stop flashing and stay green. The monitor will still function as
normal during this period but should no t be used for critical listening or referencing. Running any signal

through the moni tor will speed this process up.

2 Safety Considerations

2.1 Genera l

Before proceeding to connect y our Quested monitor to the AC power supply , please read the following
safety information:-

CAUTION: RISK OF ELECTRICAL SHO CK. REFER SERVICING TO QUALIFIED

PERSONNEL.

THE POWER C ORD MUST ALWAYS BE REMO VED BEFORE THE AMPLIFIER
IS
DISMANTLED.

WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRICAL SH O CK, DO N OT EXPOSE

THIS

APPLIANCE TO RAIN OR MOISTURE.

WARNING: THIS APPLIANCE MUST BE EARTHED.

The cores in the supplied mains lead are colour coded in accordance with the following code:

Green and Yellow: Earth
Blue: Neutral
Brown: Live

As the colours of these wires may n ot correspond with the coloured markings iden tifying the terminals
in your plug, proceed as follows:

4

The wire, which is coloured green and yellow, must be connected to the terminal in the
plug, which is marked with the let ter ‘E’ or by the earth symbol, or coloured green and
yellow.

The wire, which is coloured blue, must be connected t o t he terminal in the plug which is

marked with the letter ‘N’ or coloured black.

The wire, which is coloured brown, must be connected to the terminal in

the plug which is

marked with the letter ‘L’ or coloured red.

NOTE: For certain countries the power cord will be supplied with an integral moulded plug to satisfy

national safety standards.

CAUTION: THE REAR PANEL OF THE S8 IS PART OF THE HEAT SINKING

ARRANGEMENT

AND WILL BEC OME WARM.

CAUTION: THIS UNIT C ONTAIN’S MAGNETIC COMPONENTS, WHI CH CAN AFFECT

ADJACENT SENSITIVE EQUIPMENT.

2.2 Heari ng damag e

This equipment can deliver sound pressure levels in excess of 100 dB. At this level permanent hearing
damage can occur and exposure to this level of sound, even for relatively short periods (see table
below), can be harmful. Of equal importance to the maximum level of sound is the exposure to high
levels of sound for extended periods. There are no internationally agreed limits and different countries
have different limits, which are measured in differing ways. IT IS THEREFORE IMPORTAN T THAT

THE

USER ESTABLISHES THE RECOMMENDED, AND IN SOME TERRITORIES, LEGAL LIMI TS

WHICH ARE IN

PLACE.

As a guide the table below shows the levels that are acceptable in the majority of Western Europe, the
US and Canada.

dB(A) Lis t e n i n g t ime per day

90 8 hours
95 2.4 hours
100 40 minutes
105 15 minutes
110 5 minutes
115 and over Not at all

It is also importan t to n ote that the effect of exposure to sound is cumulative. Having listened to
sound, for example for 15 minutes at 105 dB, then further exposure to noise levels above 80 dB
should be avoided until the next day.

3 Unpacking

This Quested product has been carefully manufactured, tested and packed to ensure that it arrives in
a flawless condition. The co mponent parts of the packing have been th oughtfully designed to offer
sufficien t protection during transportation, yet remain fully recyclable and should be retained for
future use. Also included in a separate bag will be the appropriate p ower cord for your country.

4 Installation

4.1 Positio n i n g

The S8 is designed to be mounted vertically and will also function if turned on its side. However it

5

should be noted that t here will be a reduction in its th ermal performance of up to 25% if positioned

horizon tally. (See section 5.2 Thermal, fo r implications.)

The S8 is tolerant of a variety of mounting positions including stand, shelf, table or wall

mounting. Which ever way is chosen, the support should be rigid and must not vibrate when th e
monitor is driven. Vibrations will result in lack of low frequency definition. The optimum locati on for

the

monitors within a room is best determined by experimenting and placing the speaker in a variety of

positions. The shape of the room, normal listening position and room treatmen t will all

have an effect

on determining the speakers’ final positioning. It is possible to soffit mount the S8, however it is

essential tha t adequate airflow be provided behind the soffit to ensure the amplifier is adequately
cooled.

4.2 Gril l

The S8 has the option of a cloth grill, which will offer some protection to the tweeter and bass driver.
It is no t designed to pro tect the speakers during transit and it is recommended that the original packing
should be retained for this purpose. Like all types of speaker pro tection or covering, the grill makes a
small difference to the HF acoustic performance, which, for the majority of users, will not be
no ticeable.

4.3 Al i g n i n g Speaker s

The speakers should be p ositioned so that the axis (an imaginary line drawn from the acoustic centre
of the left and right monit or — see line drawing on page 13 of this manual) should cross between 0.5
and 1 metre behind the engineer’s ear p osition, for the following reasons:-

a) T o obtain the most accurate imaging, both front to rear and side to side and also to

achieve as large a listening area as possible so that the engineer can move and

opera te the console without perceiving a change in charact er of the monitors.

b) To enable listening for long periods of time without suffering strain or fatigue.

For details of pos itioni n g a nd al i g n i n g th e speak er s for m u lti-cha n n e l syst e ms s uch as 5.1,

7.1 etc.

see the d eta i l ed i nstructio n s contained in th e SB.1 s eries s ub-woof er user ma n ual.

Below is a sketch showing positioning of speakers. The S8 is suitable for a wide variety of applications,
therefore the distance apart may range from less than 1 m to 4 m. However, the principle of the
triangle and the axis of the 2 speakers crossing behind the listening position remains.

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The height and angle of mounting the speaker is equally as important. The correct height and angle
should result in the axis being at ear level when the engineer is sitting in his normal position at
the
console.

4.4 Wal l Mo unting/Stand Mounti ng

The S8 has built in mounting points that are located on the base of the cabinet and are suitable for
Omnimount ™ brackets (the S8 uses the 100 series:- 10 0 WB or 100 CB or ST) and also Quested
stands. The position of the mounting points are indicated on the line drawing on page 13 of this

7

manual. BRACKET MOUNTING OF ANY HEAVY SPEAKER INVOLVES SERIOUS SAFETY

ISSUES. IT IS IMP ORTANT TO FOLLOW THESE GUIDELINES CAREFULLY AND TO READ THE
INSTRUCTIONS THAT

AC C OMPANY THE MOUNTING HARDWARE.

When fixing the mounti ng plate to the loudspeaker:

• The bolt length must always penetrate at least 20 mm into th e cabinet base. For the
recommended Omnimount™ plate, the minimum bolt length is 25 mm.

• Always use locking washers and thread lock compound.

• Always use all of the M6 bol ts.

• Because the cabinet is a source of vibration, the bolts must be properly tightened, but
caution must be exercised as over- tightening could damage the case. Always tighten the
bolts a li ttle at a time in order to spread the stress over the area of the mounting plate. If a
torque wrench is available the recommended final torque is 6 Nm (4 lbf-feet). A 200 mm (8”)
spanner will achieve the appropriate torque without needing hard work.

• If the Omnimount ™ bracket is being used and the cabinet angled downwards, orient the
mounting plate so that the ball and socket are closer to the FRONT of the cabinet. BE

CAREFUL

WHEN POINTING THE S8 AT SHARP ANGLES DOWN (MORE THAN 30°) AS THE
CENTRE OF GRAVITY IS MOVED FORWARD CAU SING HIGH BENDING TORQ UE
AT THE CLAMP, PLACING EXCESSIVE LOAD O N THE BALL AND CLAMP OF THE
OMNIMOUNT™ AND THE CABINET FIXING
POINTS. (IF IN DO UBT ASK.)

• The cabinet may safely be suspended upside down from a ceiling or top moun ted bracket,
but the mounting plate should be oriented so tha t the ball and socket are closer to the REAR of
the cabinet.

IT IS THE RESPONSIBILITY OF THE OWNER TO ENSURE THAT THE BUILDING
STRUCTURE AND
WALL/CEILING FIXTURES ARE STRONG ENOUGH TO SAFELY BEAR THE

IMPO SED LOAD.

The mounting plate holes are sealed by M6 x 16 mm nylon countersunk machine screws. These will

need to be removed before the cabinet can be screwed onto the mounting bracket.

THESE NYLON SCREWS SH OULD NOT BE US ED TO MOUNT THE CABINET, THEY ARE

NOT OF

SUFFICIENT STRENGTH. A STEEL MACHINE SCREW OF AT LEAST 25 mm IN LENGTH

SHOULD BE USED

FOR THIS PURPOSE. If the S 8 is subsequently removed from the bracket, the mounting holes

will need to be re-sealed using the nylon screws or some other suitable sealan t.

4.5 El ectrica l Connectio n

4.5.1 Safety Earthing

This product has been designed to comply with international safety standards. It is essential
that the green/yellow core of the mains cable, or the ground pin of a 3-pin moulded plug, is
connected to th e electrical installations safety ear th or ground. It is internally connected to all
exposed metal surfaces and it is essential for personal safety as well as proper operation of
the product. The audio signal in-put is electronically balanced and does no t need the
disconnection of any safety earth for the avoidance of hum loo ps.

4.5.2 Voltage Setting

The set voltage is indicated on the rear panel of the unit, adjacent to the IEC inlet connector.
At this setting there is an acceptable tolerance over which the performance of the unit will

8

continue to meet its specifications. (See power requirements o n page 12 of his manual.) For

the 230V setting this is 160V to 255V and for the 115V setting it is 80V to 127V. If th e unit is
connected to voltages in excess of its maximum, damage is likely to occur which may not be

recoverable from without qualified service at ten tion.

To change the set voltage, the amp must be removed from the speaker. The power and
signal cables must be discon nected before continuing. Remove the 6 x M4 socke t screws from
the left and right hand side edges of the amplifier. Carefully remove the back-panel and you
will see 4 wires and one 3-way cable form connecting to the amplifier with various connectors.
Note t he orientation and p osition of them all and then disconnect. If you look at the
amplifier, you will see a PCB mounted on the rear of the IEC inlet connector. Marked on the
PCB you will see the 2 terminals marked with the set voltage (see diagram). Locate and move
the connectors to the o ther voltage tap, noting tha t the coloured wires correspond with the
printing on the PCB. Reconnec t the wires from t he cabinet to the amplifier and replace the
amplifier using the 6 bolts. You must now change the fuse located in the IEC inlet socket for
the correct one as indicated on the back panel. IT IS IM PORTANT THA T YOU NOW
MARK THE REAR OF THE

UNIT W I TH THE NEW SET VOLTAGE.

Exploded view of small PCB viewed from above showing the voltage selection connectors with
alternative pins for the 115V and 230V settings.

4.5.3 Fuse Setting

It is very unlikely th e fuse will fail during no rmal use, but should this

occur the situation must

be approached with so me caution. Check that the mains voltage set ting is correct for

your

installation supply and that the original fuse was the correct rating. (See 9.2 Spares) The fuse
may blow if the unit is subjected to mains power surges or spikes, or if the mains wiring has
any poor or faulty connections, in which case a qualified electrician should be consulted. Very
occasionally a fuse can become degraded after many years of service and simply replacing it
with a new one will restore the system.

The fuse is housed in a unit integral with the IEC inlet connector (see rear panel drawing page
of this manual). To gain access to the fuse remove the power cord and unclip the fuse carrier
using a flat blade. A spare fuse of the correct rating is also provided within the same carrier. If
none of the above is the cause of the fault it is likely tha t the unit has suffered an internal
componen t failure and will need returning to a qualified agent for servicing IF THE

REPLACEMENT FUSE SH O ULD FAIL DIS C O N NECT FROM THE MAINS

IMMEDIATELY AND HAVE

THE UNIT PR OFESSIONALLY REPAIRED BEFORE ATTEMPTING TO U SE IT.

4.6 Audio conn e ctio n s

The audio signal input is RF filtered and electronically balanced to ensure a high level of rejection

9

for common mode interference signals and to give a professional connection to external equipmen t. It
is essential for optimal use of these specifications th at a professional grade, balanced two-core
screened cable is used.

Source Ba la nced Pin 2 hot

In accordance with in ternational standards, 3-pin XLR style input connectors are used, with pin

2 being designated t he ‘in-phase’ or ‘hot’ terminal and pin 3, the ‘out of phase’ or ‘cold’ terminal.

Pin 1 is connected to the chassis ground and must be connected to t he screen of the audio

interconnecting cable. This is necessary to ensure p roper compliance with European Standards for

Electromagnetic Compatibility. Pin 1 carries no signal voltages or currents and is provided purely fo r

screening purp oses. It should no t be connected to either pin 2 or pin 3.

Source Unbalanced Pin 2 Hot

If the equipment providing the audio signal has an unbalanced output, then the interconnecting audio

cable should be wired so that the hot output of the source is connected to pin 2 of speaker input XLR

and the ground of the source connected to pin 3. The screen of the interconnec ting audio cable should

be connected to pin 1 of the input connector only. The r e mus t be no co n n ect ion be twe en the

ground connection of the unbala nced o utput and the pin 1 ground con n ection of t h e input

connector.

Source Unbalanced Phono

If the source output is a phono socket, then the cent re pin of the phono plug should be wired to pin 2

of the speaker input XLR and the outer phono casing to pin 3. The wire from pin 1 of the XLR will

no t be con nected to the terminals of the phono plug. Strict adherence to this will help to eliminate

ground loop hums and RF break through.

10

Source Unbalanced Phono 2 Core cable

5 OPERATIONAL CONSIDERATIONS

5.1 Main s O n- Off Switching and l evel

On-Off switching is provided by a rocker switch on the rear panel. Intelligent circuitry ensures
noiseless power-on and power off.

5.2 Thermal

The ou tput devices of the internal power amplifiers are mounted onto an internal heatsink,
which heats up and reaches temperatures well above that of ambient. The design is such that
no forced cooling is necessary, provided sufficient free space can be maintained around the
cabinet to allow the air to circulate freely. The internal circuitry monitors temperature to
maintain its safe operating area. Should t his detect unsafe temperatures, output is muted to
protect the amplifier. You will need to turn the unit off and on to reset the pro tection. This
will
only work if the amplifiers temperature has fallen within its safe working threshold.

5.3 Front Pa n e l Indicators

A multi function LED is mounted behind the LOGO badge on the fron t of the cabinet. On
initial turn on the LED will flash green this indicates that the amplifier is warming up (see

11

section 1.1 Class A-B amplifiers) the LED will be continuously green when the amplifier has
warmed up and is ready for normal operation. The LED will flicker red with music peaks to indicate that the
amplifier is 2db under clip. The clip indication should be used as a guide tha t the amplifier is approaching

clip, which should be avoided for audible integrity. If the amplifier detects a fault or over heats

the LED will be continuously red. If the amplifier has over heated and the LED has turned red

refer to section 5.2 Thermal.

5.4 Signa l Level

Input sensitivity can be adjusted with the ten position rotary switch recessed in the rear panel

by using a flat bladed screwdriver. The control has an 18dB range in 2dB steps and accurately

sets the SPL level for a kn own input signal level. Wit h the switch set at the 0dB position, 0dBu

of pink n oise will produce 96dB SPL at 1 meter.

5.5 Co ntour Sel ectors

There are two switch groups that control the HF and LF con tour set tings. These can be used to

adjust for room conditions or personal preference. The nominal flat position is indicated with a

flat line. The spe a k er will only operate correctly if the switch e s are i n o n e of th e

positions sho wn on the rear panel.

6 TECHNICAL SPECIFICATION

S8

Dimensions: 300(w) x 428(h) x 334(d) mm
Weight: 17.6 kgs
Drivers: Bass cone - 1 x 200 mm (8 ”)

High Frequency soft dome - 1 x 28 mm (1 ⅛”)

Maximum SPL: 110 dB (c) continuous pink n oise @ 1 m (122 dB (c) per pair RMS

music)

Frequency Response: 50 Hz-20 kHz ± 2 dB
Connector: XLR and ¼ inch Jack combo socket
Impedance: 10 k Ω electronically balanced with RF filters
Wiring: Pin 1 ground Sleeve

Pin 2 hot Tip
Pin 3 cold Ring

Sensitivity: -12 dBu t o +6 dBu for 96 dB SPL @ 1 m set by 10 position ro tary switch on

rear
Subsonic: -3dB @ 20 Hz, 24dB/oct
Ultrasonic: -3dB @ 75kHz, 4dB/oct
Crossover: 1k40
LF EQ: -2/-4 @ 42 Hz

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HF EQ: +/- 2dB @ 10 kHz

POWER AMPLIFIER

LF output power: > 220 W RMS continuous (note 1)
HF output power: > 150 W RMS continuous (note 1)
THD: < 0.025% at levels up to 1 dB below clip, 20 Hz-20 kHz. typ 0.005% @ 1kHz.
Hum & Noise: > -100 dB referred to clip

NOTE 1: T he con tinuous rating is for a period not exceeding 5 minutes with unrestricted airflow (100
mm clearance) around the amplifier heatsinks and an ambient temperature no t exceeding 30ºC.

INDICATORS

Amplifier Warming up: Front mounted flashing green LED indicates that the amplifier is

warming up t o reach peak performance.
Normal operation: green LED indicates power applied and normal operatio n.
Clip: Red LED 2 dB before amplifier clip.
Fault indication: Red constan tly on indicates fault.

POWER REQUIREMENTS

Voltage: Set by internal plugs: nominal 115V or 230V @ 50-60 Hz AC

230V setting: min 1 60V; restricted ou tput power: max 255V

115V setting: min 8 0V; restricted out put power: max 127V

C ONSUMPTION

Quiescent: 38 W
Typical use: 100W (average music)
Max: 160W (average music)

Note: 0 dBu = 775 mV into open circuit

7 S8 LINE DRAWING

13

300.0mm/11.8"

Acoustic

Centre

280mm

11"

428.0mm

16.8"

334.0mm/13.1"

103.0mm/5.9"

127.0mm/5.0"

69.5mm/2.7"

34.75mm/4.0"

Cabinet (bottom view)

150.0mm

5.9"

150.0mm

5.9"

167.0mm/6.6"167.0mm/6.6"

64.0mm

2.5"

8 Guarantee

The S8 electronics are guaranteed for 5 years from date of purchase. All other parts are guaran teed
for 24 mon ths. If any part o f the product is found to be defective because of faulty manufacture

within

these periods , Quested, th rough its authorised distribution network, will effect repair or replacement,
at its discretion, free o f charge providing that::

a) The fault is reported to the authorised distributo r.
b) Proof of purchase is provided.
c) The fault is no t caused by misuse, neglect, or faulty operation by the user.
d) The fault is not a result of fair wear and tear.
e) The equipment has no t been modified in any way.
f) The equipment has not been taken apart or tampered with in anyway other than described

in the service manual for the adjustment and replacemen t of user accessible items.

The guarantee does no t cover:

a) Damage during transi t
b) Damage to diaphragms, cones and o ther speaker parts as a result of the over-driving of the

monitors or by faulty installation or connection.
c) Damage caused by incorrect installation or during installation caused by incorrect handling.
d) The cost of carriage to or from th e authorised repairer.

9 APPENDIX

9.1 Acce ssor i e s

14

Grill

Omnimount ™ plus fixings
Quested S series stands (with unique coupling system)

9.2 Spares

De scription Part Number

S8

LS2203 8" 8 ohm Bass Driver Q01-0022

TW20 8Ω shielded soft dome Q03-0040

Fuses T3.15A L01-0010

Fuses T6.3A L01-0018

9.3 Driver r eplace m ent procedure

If it is necessary to replace the bass driver, place the cabinet on its rear and, using a 4 mm

hex head driver, remove all of the bolts. As with most objects held by a series o f bolts, these

bolts should initially be loosened a little, one at a time rather than each bolt being fully

removed whilst the other bolts remain fully tightened. When replacing the bass driver, the

gasket behind the driver should be replaced with the new gasket that will be supplied with

your new driver.

Tweeter replace ment proc edure

The tweeter is secured by 4 x M4 machine screws. Remo ve these with a 2.5mm hex drive.

Ta ke out the tweeter and disconnect the two wires, n oting which colour goes to which

terminal. If on removing the 4 screws tha t hold the tweeter th ere is any difficulty in removing

the unit, do n ot try to force a blade between the cabinet and tweeter, but use a small narrow

bladed screwdriver in one of the screw holes to gently lever out the tweeter. If it is necessary to

replace the diaphragm:

a) Remove th e 3 pozi screws on the fron t plate of the tweeter using a number 1 p ozi driver.

b) Remove diaphragm assembly and replace with the new diaphragm. The ferrofluid has t he

ap pearance of oil and is dark brown in colour and should cover about 1/3 of the coil. If

t here is less than this then additional Ferrofluid should be added (generally the fluid will

only need to be added after you have changed the diaphram 2 or 3 times). This can be

obtained from your dealer/distributor or directly from Quested. It should be n oted that

ferrofluid is best added as shown in the diagram below and not from the syringe that it is

dispensed in. The fluid should never cover more than 1/2 the coil.

Ferrofluid

15

Dip wire in ferrofluid, a small amount will be retained on the wire

hold wire over the tweeter gap and the magnet will attrac t the

fluid from the wire int o the gap. Do this 3 or 4 times in different

position on the tweeter, then check by inserting the new diaphragm

to see the amount of fluid in the tweeter.

c) Re-assemble.