Turbosound QLight TQ-425 User manual

QLIGHTSERIES
TQ-425
USER MANUAL
Turbosound Ltd.
Star Road, Partridge Green
West Sussex RH13 8RY England
Tel: [phone] Fax: [phone]
web: www.turbosound.com
Issue 1.0 Copyright 2000 Turbosound Ltd.

user manual
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CONTENTS
Thanks................................................................................................................................................ 3
Unpacking.......................................................................................................................................... 3
Introduction ....................................................................................................................................... 3
Features ............................................................................................................................................. 4
Product Summary ............................................................................................................................. 4
System Requirements....................................................................................................................... 5
Amplifier considerations................................................................................................................... 5
Equalisation ....................................................................................................................................... 6
Mounting and fixing.......................................................................................................................... 6
Choosing the best location ............................................................................................................... 8
Maintenance ...................................................................................................................................... 8
Appendix A: Technical Specifications.............................................................................................. 9
Appendix B: Spares and Accessories............................................................................................... 9
Appendix C: Warranty..................................................................................................................... 10

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Thanks
Thank you for choosing a TURBOSOUND TQ-425 loudspeaker product for your application. Please
spare a little time to digest the contents of this manual, so that you can obtain the best possible
performance from this unit.
All TURBOSOUND products are carefully engineered for world class performance and reliability.
If you would like further information about this or any other TURBOSOUND product, please
contact us. Detailed product information is available on our web site at www.turbosound.com
We look forward to helping you in the near future.
Unpacking the TQ-425 loudspeaker
After unpacking the unit please check carefully for damage. If damage is found, please notify the
carrier concerned at once. You, the consignee, must instigate any claim. Please retain all
packaging in case of future re-shipment.
Introduction
Congratulations, you have just purchased a professional loudspeaker system from the renowned
Turbosound range, designed to give you the best in audio quality and many years of reliable,
trouble free operation. It offers superior audio quality, full technical documentation, and rigging
and flying hardware options. Please read through this manual carefully before you attempt to
operate the loudspeaker system. It contains valuable information enabling you to quickly and
easily set up and connect the loudspeakers, important system and set-up checks together with
positioning and mounting instructions.

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Features
♦Superb audio quality
Superb audio qualitySuperb audio quality
Superb audio quality: carefully designed and matched 15” LF loudspeaker drive units are used
to give you exceptional performance and many years of reliable, trouble free operation.
♦Wide dynamic range
Wide dynamic rangeWide dynamic range
Wide dynamic range: the drive units are capable of handling large amounts of amplifier
power in order to achieve high SPL without losing headroom.
♦Solid construction
Solid constructionSolid construction
Solid construction: all Turbosound QLight series cabinets are built from high grade birch
plywood, rebated, screwed and glued together for maximum rigidity and durability.
♦Integral rigging points
Integral rigging pointsIntegral rigging points
Integral rigging points: fitted as standard, enabling use with optional Turbosound flying
hardware.
♦Compact enclosure
Compact enclosureCompact enclosure
Compact enclosure: the overall dimensions of the TQ-425 have been kept as small as possible
to enable portable use as well as permanent installations.
Product Summary
The TQ-425 is a front loaded vented subwoofer designed to combine with QLight series
enclosures to give a high quality, full range sound reinforcement system ideally suited to all
corporate, industrial, theatre and audio visual applications.
The TQ-425 consists of two 4” voice coil, 15” low frequency drivers in a compact vented
enclosure, optimally tuned to reproduce high sound pressure levels at bass and sub-bass
frequencies.
The TQ-425 is designed for use with the LMS-D6 digital loudspeaker management system, which
provides 24dB/octave crossovers and a wide range of factory preset programs for QLight series
and other Turbosound products.
The enclosure is constructed from 3/4” (18mm) birch plywood, heavily braced internally, glued
and screwed together for maximum strength. It is finished in a durable black semi-matt textured
paint (also available in TurboBluetextured paint). The loudspeaker drive units are protected by a
foam/expanded steel mesh grille.
Flush handles are provided for easy lifting and carrying, and a pole mount socket is included on
the top to allow QLight series enclosures to be mounted at the correct distance above the
subwoofer. In addition, steel flying strips are optionally available to enable the TQ-425 to be
permanently installed in either a vertical or horizontal orientation.
Two Neutrik Speakon connectors provide input and loop out connections to the enclosure. The
TQ-425 is fitted with four heavy duty wheels to enable easy transportation.

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System Requirements
The TQ-425 is a passive (non-powered) loudspeaker system. It requires the use of one amplifier
channel for correct operation. Frequency splitting between the low frequency enclosure and the
mid-high frequency enclosure is accomplished by an external electronic crossover. The LMS-D6
loudspeaker management system is recommended for this purpose.
Amplifier considerations
Turbosound speaker enclosures should be driven by high quality power amplifiers designed for
true professional use. Such amplifiers will have balanced inputs, DC and RF fault protection, and
well designed cooling systems for reliability.
The program power listed in the loudspeaker’s technical specification is the best guide to the size
of amplifier required for general purpose applications. The amplifier should therefore be capable
of delivering long term broadband power equal to the loudspeaker’s program power rating at the
loudspeaker’s stated nominal impedance. This approach allows sufficient headroom to generate
good dynamic range.
RECOMMENDED AMPLIFIER POWER RATINGS:
RECOMMENDED AMPLIFIER POWER RATINGS:RECOMMENDED AMPLIFIER POWER RATINGS:
RECOMMENDED AMPLIFIER POWER RATINGS:
The amplifier's rated r.m.s. continuous power output (20Hz – 20kHz, per
channel) should be equal to the program power handling of the
loudspeaker at its nominal impedance.
In general, the more powerful the amplifier the better it will sound, provided that it is not driven
into sustained clipping. It should be understood that overdriving an insufficiently powered
amplifier is more likely to cause loudspeaker damage – the total energy in a heavily clipped signal
is far higher than in an unclipped signal – than operating a more powerful amplifier within its
ratings.
One controller can be used to feed several amplifiers as long as all the amplifiers are the same (or
have the same gain ratings). More than one controller may be required if the amplifiers are of
different gain or type. Please contact your dealer if you require help in this area.

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Equalisation
In order to compensate for the room acoustics, the TQ-425 requires only minimal equalisation. As
in any system, over-equalisation introduces phase shifts, distortion and a reduction in headroom,
usually causing more problems than it cures.
Under most circumstances a 1/3 or 1/2 octave graphic equaliser will generally be adequate, with
the fader settings applied smoothly and as little as possible for the required room compensation.
Most rooms will have resonances that will be excited at particular frequencies needing some
cut
to help tame the sound, these problems are most pronounced at the lower frequencies where
speakers generally exhibit very little directional control. If you find that the system needs a lot of
boost at lower frequencies you may need additional sub-bass units as stated above. It is good
practice to use as little equalisation as possible, aiming to cut frequencies rather than adding large
amounts of boost.
Mounting and Fixing
A versatile range of mounting hardware is available for the TQ-425 that allows it to be used in a
variety of ways, in either mobile applications or permanent installations.
A top hat stand type fitting
A top hat stand type fittingA top hat stand type fitting
A top hat stand type fitting is mounted in the top of the
cabinet to allow complemetary QLight enclosures such
as the TQ-440 to be mounted at the correct distance
above the subwoofer using a straight 35mm pole.

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Side-mounted flying strips
Side-mounted flying stripsSide-mounted flying strips
Side-mounted flying strips can be fitted to the sides of the cabinet to enable enclosures to be
flown as part of a permanent installation. Two different lengths of flying strips are optionally
available for flying the enclosure in either a vertical (FF-425L) or horizontal (FF-425S) orientation.
These are fitted by removing the countersunk bolts on the top and sides of the cabinet and
replacing them with the M10 bolts provided with the hardware. Two flying strips are required for
each enclosure. This method offers a simple and cost effective method of flying single or multiple
TQ-425 enclosures, with the load being taken through the steel strips rather than through the
woodwork of the enclosure. Enclosures may be arranged in a vertical column by coupling the
flying strips together using QL-75 quicklinks or shackles.
WARNING: Rigging eyebolts must not be used for flying this enclosure. You must use the optional
WARNING: Rigging eyebolts must not be used for flying this enclosure. You must use the optionalWARNING: Rigging eyebolts must not be used for flying this enclosure. You must use the optional
WARNING: Rigging eyebolts must not be used for flying this enclosure. You must use the optional
Turbosound steel flying strips described above.
Turbosound steel flying strips described above.Turbosound steel flying strips described above.
Turbosound steel flying strips described above.
Any installation, whether temporary or permanent, must be securely attached to the structure of
the building using chain, steel wires or web straps which are certified and load rated for the
purpose. The combined weight of the sound system, its cables and the rigging system must be
safely carried by the points at which attachment is made to the building or structure. Great care
must be taken in selecting the attachment points and methods, being absolutely sure of the load
carrying capacity of points chosen.
NOTE: The rigging of loudspeaker systems is an extremely serious matter with potentially lethal
consequences should anything go wrong. It is of vital importance that you, or other people rigging
the system, are suitably qualified to do so and have a full understanding of all the factors involved
with safety as a number one priority. Turbosound accepts no responsibility for any accident,
damage or failure of any rigged system. This rigging information is specifically related to the
requirements of the TQ-425 only. For more detailed information on the whole topic of rigging
various handbooks are available. If you are in any doubt contact your Turbosound dealer who will
be able to refer you to an experienced rigging company.

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Choosing the best location
When using any QLight system, certain room parameters will affect the resultant sound quality
and coverage. For example, any boundary like a wall or floor will lift certain frequencies. If you are
placing the unit in a corner then a lift at the bass end is to be expected and it may sound rather
boomy. This can be compensated for moving the speaker or cutting low frequencies with a
graphic equaliser.
When speakers are flown in free space then boundary effects are minimised. The result is a
smooth frequency response without any boost at odd frequencies, but the bass end may appear
subjectively light. In this case increase the sub-bass level to bring the low end up.
The relationship between sound pressure level and distance is an “inverse square law” so
remember that every time the distance from the sound source is doubled the sound level
decreases by 6dB. For every 3dB increase of speaker output you need a doubling of input power
and you can work out the wattage input needed to give the required SPL levels at various
distances from the loudspeaker(s).
Maintenance
If either of the drive units in the cabinet should cease functioning and needs a replacement recone
you are advised to remove the faulty unit from the cabinet and send it to a professional recone
service authorised to recone Turbosound loudspeakers. This will ensure the continued high
performance of your TQ-425.
Removal of the 15” drivers
1. Unscrew the eight countersunk screws from the two vertical battens which hold the protective
grille in place. Set the battens, grille and fixing screws aside for later re-assembly.
2. Undo the eight M6 x 30mm Allen head bolts holding the driver in place and carefully pull it
out and away from the cabinet. WARNING - This unit is heavy! Disconnect the cables from the
drive unit and completely remove the driver from the cabinet. Make a note of the driver
polarity for later reconnection.
3. To reinstate the drivers, simply reverse the above procedure making sure you observe the
correct polarity when reconnecting the cables back into the terminals of the drive units.
For any other servicing requirements please contact your Turbosound dealer or authorised service
centre.

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APPENDIX A
Technical Specifications
Dimensions 836mm x 511mm x 632mm (32.9” x 20.1” x 24.9”)
Net weight 68kgs (149.6lbs)
Components 2 x 15” (381mm) LF drivers
Frequency response 45Hz – 200Hz ±4dB
Maximum SPL 132dB continuous, 138dB peak
Construction 18mm (3/4”) birch plywood throughout; rebated, screwed and glued.
Finished in black semi-matt textured paint. Recessed carrying
handles. Integral 35mm pole mount
Grille Reticulated foam on expanded steel mesh
Connectors (2) x Neutrik Speakon NL4MP, wired pin1+:+ve, pin 1-: -ve
Options TurboBlue semi-matt textured paint
Due to continuing product improvement the above specifications are subject to change.
APPENDIX B
Spares and accessories
LS-1518 15” (381mm) LF loudspeaker
RC-1518 Recone kit for LS-1518
MG-425 Replacement foam / metal grille
Flying accessories
FF-425L Flying strips (2 required per enclosure) for vertical orientation
FF-425S Flying strips (2 required per enclosure) for horizontal orienation

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APPENDIX C: WARRANTY
Limited Warranty
This Turbosound loudspeaker product is warranted to the original end-user purchaser and all
subsequent owners for a period of two (2) years from the original date of purchase.
Warranty Coverage
Warranty coverage includes defects in materials and workmanship. It does not include:
♦damage caused by accident, misuse, abuse, neglect or modification by any person other than
an authorised Turbosound representative,
♦damage caused by failure to operate the product in accordance with the instructions
contained in the user manual,
♦damage occuring during shipment in transit,
♦claims based on any misrepresentation by the seller,
♦products which do not have the original components as specified in the product engineering
information,
♦products on which the serial number has been removed or defaced.
Shipping
Should any fault develop with a component of your Turbosound system, please return the
product, freight pre-paid, in its original packing carton, along with proof of purchase such as the
original bill of sale or receipted invoice, and a description of the suspected fault to Turbosound
Ltd. (Att: Customer Service), Star Road, Partridge Green, West Sussex RH13 8RY, England, or your
local authorised Turbosound representative. The product serial number must be quoted in all
correspondence relating to the claim. Insurance is recommended, as Turbosound or its
representatives are not liable for loss or damage in transit. Turbosound will pay for return freight
costs should repairs be covered under warranty.

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Incidental and consequential damages
Turbosound's liability is limited to the repair or replacement, at our option, of any defective
product, and shall not be liable for any incidental and consequential damages including, without
limitation, injury to persons or property or loss of use.
Limitation of implied warranties
All implied warranties, including warranties of merchantability and fitness for a particular
purpose, are limited in duration to the length of this warranty.
This warranty is in addition to, and in no way detracts from, your statutory rights as a consumer.
No other warranty is expressed or implied.
Please record your purchase information below for future reference:
Dealer Name ..................................................................................................................................
Dealer Address ..............................................................................................................................
........................................................................................................................................................
........................................................................................................................................................
Post / Zip Code ..............................................................................................................................
Dealer telephone / fax ...................................................................................................................
Invoice number .............................................................................................................................
Date of purchase ...........................................................................................................................
Unit serial number ........................................................................................................................

Turbosound Ltd.
Star Road, Partridge Green
West Sussex RH13 8RY England
Tel: [phone] Fax: [phone]
web: www.turbosound.com