Turbosound TXD-121 User manual

TXD SERIES
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 

2003 Turbosound Ltd.

user manual
TXD series
TXD series manual
page 2
CONTENTS
Contents........................................................................................................................................2
Introduction ..................................................................................................................................3
Thanks ......................................................................................................................................3
Unpacking the TXD series loudspeaker..................................................................................3
Features ........................................................................................................................................4
Product Range Summary.............................................................................................................5
TXD-121....................................................................................................................................5
TXD-151....................................................................................................................................5
TXD-115....................................................................................................................................6
TXD-215....................................................................................................................................7
TXD-118....................................................................................................................................7
TXD-12M ..................................................................................................................................8
System requirements...................................................................................................................9
Bi-amplified operation...........................................................................................................10
Amplifier considerations.......................................................................................................11
Equalisation ...........................................................................................................................11
Dispersion ..............................................................................................................................11
System Connections ..................................................................................................................13
Passive two way system .......................................................................................................13
Passive full-range system with subs ....................................................................................13
Passive full-range system with subs ....................................................................................14
Passive full-range system with subs ....................................................................................14
Live performance monitor system .......................................................................................15
Bi-amplified system with subs..............................................................................................15
Club system with multiple zones..........................................................................................16
Mounting and fixing...................................................................................................................17
Choosing the best location ........................................................................................................18
Maintenance ...............................................................................................................................19
Removal of the low frequency driver(s)...............................................................................19
Removal of the high frequency compression driver ...........................................................19
Appendix B.............................................................................................................................20
Technical Specifications........................................................................................................20
Appendix C .................................................................................................................................22
Spares and Accessories ........................................................................................................22
Flying Accessories .................................................................................................................22
Appendix A .................................................................................................................................23
Use of thread locking compounds........................................................................................23
The parts may be disassembled by hand if required...............................................................23
Appendix D .................................................................................................................................24
Limited Warranty...................................................................................................................24

user manual
TXD series
TXD series manual
page 3
INTRODUCTION
Thanks
Thank you for choosing a TURBOSOUND TXD series loudspeaker product for your application.
Please spare a little time to read 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.
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.
Unpacking the TXD series 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.

user manual
TXD series
TXD series manual
page 4
FEATURES
•Superb audio quality
Superb audio qualitySuperb audio quality
Superb audio quality: carefully designed and matched loudspeaker drive units are used to give
you exceptional performance and many years of reliable, trouble free operation.
•High quality loudspeaker components
High quality loudspeaker componentsHigh quality loudspeaker components
High quality loudspeaker components are used throughout the range. Low frequency drivers
are specified for high sensitivity and durability, while high frequency drivers are selected for
consistent and reliable performance.
•High frequency protection system
High frequency protection systemHigh frequency protection system
High frequency protection system: two-stage thermal overload circuits operate on all two-way
products to prevent damage to the HF drive units from both transient peaks and long term
heating effects.
•Professi
ProfessiProfessi
Professional appearance
onal appearanceonal appearance
onal appearance:
TXD series enclosures are equally suited to live sound and DJ
applications as well as permanent installations.
•Easy transportability
Easy transportabilityEasy transportability
Easy transportability: comfortable, ergonomic flush handles are provided on all TXD series
enclosures for easy lifting and transportation in mobile sound reinforcement applications.
•Wide dispersion
Wide dispersionWide dispersion
Wide dispersion: TXD series enclosures are designed to give wide and even dispersion
patterns in order to maximise sound coverage over a given area from single loudspeakers.
•Solid construction
Solid constructionSolid construction
Solid construction: all Turbosound TXD series cabinets are built from high grade, multi-layer
birch plywood and are finished in a durable semi-matt textured paint.
•Integral rigging points
Integral rigging pointsIntegral rigging points
Integral rigging points: fitted as standard, enabling use with optional M10 shoulder eyebolts
for many types of fixed installations. TXD-121 and TXD-151 enclosures can be permanently
installed using Turbosound or PowerDrive™ wall and ceiling brackets. All models are type-
tested for load rating to ensure safe rigging.
•Pole mount and tripod stand use
Pole mount and tripod stand usePole mount and tripod stand use
Pole mount and tripod stand use is facilitated by the provision of integral pole mount fittings
on all models.
•Speakon NL4MP connectors
Speakon NL4MP connectorsSpeakon NL4MP connectors
Speakon NL4MP connectors are fitted to all TXD series enclosures, enabling simple and easy
hook-ups as well providing loop-in / loop-out facilities to additional enclosures.

user manual
TXD series
TXD series manual
page 5
PRODUCT RANGE SUMMARY
TXD-121
The TXD-121 is a compact trapezoidal passive two-way loudspeaker enclosure designed for use in
a wide variety of live sound, fixed installation and mobile DJ applications that require professional
sound quality in an easily transportable format.
It consists of a 12” reflex-loaded low frequency driver and a 1” high frequency compression driver
on a 70ºH x 40ºV dispersion HF horn in an optimally tuned trapezoidal enclosure. These high-grade
components are matched with an internal second order passive crossover network to ensure a
seamless transition between the HF and LF drivers.
The crossover incorporates a two stage thermal overload protection system which prevents
damage to the high frequency driver, reacting instantly to large transient peaks while still allowing
wide dynamic range to be maintained. Although the protection system is transparent at normal
operating levels, as the level increases the signal is gradually and imperceptibly compressed once
the critical threshold has been reached.
The cabinet is constructed from 15mm (5/8”) birch plywood, screwed and glued together for
maximum rigidity. A pole mount socket is fitted for use with optional 35mm poles and
loudspeaker stands. Two recessed flush handles are provided for easy lifting and carrying and four
rubber feet are fitted to the bottom of the cabinet. A grey powder-coated perforated steel mesh
grille protects the drivers from damage.
M10 rigging points are provided on the top and rear of the cabinet to enable it to be suspended
and angled in permanent installations using shoulder eyebolts. M8 rigging points are provided on
the rear of the cabinet for use with Turbosound wall and ceiling brackets, and these are also
compatible with PowerDrive™ wall and ceiling brackets. Two Neutrik Speakon NL4MP speaker
connectors are located on the rear panel, providing input and parallel connections to additional
TXD series cabinets or bass enclosures.
TXD-151
The TXD-151 is a trapezoidal passive two-way loudspeaker enclosure designed for use in a wide
variety of live sound, fixed installation and mobile DJ applications that require professional sound
quality in an easily transportable format.
It consists of a 15” reflex-loaded low frequency driver and a 1” high frequency compression driver
on a 70ºH x 40ºV dispersion HF horn in an optimally tuned trapezoidal enclosure. These high-grade
components are matched with an internal second order passive crossover network to ensure a
seamless transition between the HF and LF drivers.

user manual
TXD series
TXD series manual
page 6
The crossover incorporates a two stage thermal overload protection system which prevents
damage to the high frequency driver, reacting instantly to large transient peaks while still allowing
wide dynamic range to be maintained. Although the protection system is transparent at normal
operating levels, as the level increases the signal is gradually and imperceptibly compressed once
the critical threshold has been reached.
The cabinet is constructed from 15mm (5/8”) birch plywood, screwed and glued together for
maximum rigidity. A pole mount socket is fitted for use with optional 35mm poles and
loudspeaker stands. Two recessed flush handles are provided for easy lifting and carrying and four
rubber feet are fitted to the bottom of the cabinet. A grey powder-coated perforated steel mesh
grille protects the drivers from damage.
M10 rigging points are provided on the top and rear of the cabinet to enable it to be suspended
and angled in permanent installations using shoulder eyebolts. M8 rigging points are provided on
the rear of the cabinet for use with Turbosound wall and ceiling brackets, and these are also
compatible with PowerDrive™ wall and ceiling brackets. Two Neutrik Speakon NL4MP speaker
connectors are located on the rear panel, providing input and parallel connections to additional
TXD series cabinets or bass enclosures.
TXD-115
The TXD-115 is a front-loaded low frequency loudspeaker enclosure designed to give bass and
sub-bass reinforcement to TXD series 2-way enclosures in a wide variety of live sound
applications, as well as in fixed installations ranging from cafes, pubs, bars and restaurants to
retail stores and houses of worship.
It consists of a reflex-loaded 15” low frequency driver in an optimally tuned rectangular enclosure.
The TXD-115 includes a low-pass crossover network which filters high frequency signals from the
bass driver when used in conjunction with 2-way enclosures such as the TXD-121 or TXD-151,
enabling a full range system to be powered from a single amplifier channel without the need for
external electronic crossovers.
The enclosure is fitted with internal M10 threaded rigging points on the top and rear, which allow
single cabinets to be suspended and angled in fixed installations using optional M10 shoulder
eyebolts.
The cabinet is constructed from 15mm (5/8”) birch plywood, and is finished in a durable semi-matt
textured TurboBlue™ paint. Two flush handles are provided on the sides for easy lifting and
carrying, and four rubber feet are fitted to the bottom of the cabinet. Two Neutrik Speakon NL4MP
connectors provide input and parallel connections to additional TXD series cabinets.

user manual
TXD series
TXD series manual
page 7
TXD-215
The TXD-215 is a front-loaded low frequency loudspeaker enclosure designed to give bass and
sub-bass reinforcement to TXD series 2-way enclosures in a wide variety of live sound
applications, as well as in fixed installations ranging from cafes, pubs, bars and restaurants to
retail stores and houses of worship.
It consists of two reflex-loaded 15” low frequency drivers in an optimally tuned rectangular
enclosure. The TXD-215 includes a low-pass crossover network which filters high frequency
signals from the bass driver when used in conjunction with 2-way enclosures such as the TXD-121
or TXD-151, enabling a full range system to be powered from a single amplifier channel without
the need for external electronic crossovers.
The cabinet is constructed from 15mm (5/8”) birch plywood, screwed and glued together for
maximum rigidity. Pole mount sockets are fitted on the top and sides of the cabinet to enable full
range cabinets to be mounted on optional 35mm poles. When used in a horizontal format the two
side-mounted pole mounts allow two TXD series enclosures to be mounted on top of a single bass
cabinet to provide wider horizontal dispersion. Four recessed flush handles are provided for easy
lifting and carrying and the cabinet is pre-drilled for optional T4 wheels. Four rubber feet are fitted
to the bottom of the cabinet, and a grey powder-coated perforated steel mesh grille protects the
drive units from damage.
M10 rigging points are provided on the top and rear of the cabinet, which allow single cabinets to
be suspended and angled in fixed installations using optional M10 shoulder eyebolts.
Two Neutrik Speakon NL4MP connectors are located on the rear panel, providing input and
parallel connections to additional TXD series cabinets.
TXD-118
The TXD-118 is a front-loaded low frequency loudspeaker enclosure designed to give bass and
sub-bass reinforcement to TXD series 2-way enclosures in a wide variety of live sound
applications, as well as in fixed installations ranging from cafes, pubs, bars and restaurants to
retail stores and houses of worship.
It consists of a front-loaded 18” low frequency driver in a birch plywood enclosure, optimally
tuned for extended low frequency response. The TXD-118 includes a low-pass crossover network
which filters high frequency signals from the bass driver when used in conjunction with 2-way
enclosures such as the TXD-121 or TXD-151, enabling a full range system to be powered from a
single amplifier channel without the need for external electronic crossovers
The enclosure is fitted with internal M10 threaded rigging points on the top and rear, which allow
single cabinets to be suspended and angled in fixed installations using optional M10 shoulder

user manual
TXD series
TXD series manual
page 8
eyebolts. A pole mount socket is fitted to the top of the cabinet to enable two-way enclosures to be
mounted on 35mm poles.
The cabinet is constructed from 15mm (5/8”) birch plywood, and is finished in a durable semi-matt
textured TurboBlue™ paint. Two flush handles are provided on the sides for easy lifting and
carrying, and four rubber feet are fitted to the bottom of the cabinet. Two Neutrik Speakon NL4MP
connectors provide input and parallel connections to additional TXD series loudspeakers.
TXD-12M
The TXD-12M is a compact passive two-way wedge monitor enclosure designed for use in a wide
variety of live sound, fixed installation and mobile DJ applications that require professional sound
quality in an easily transportable format.
It consists of a 12” reflex-loaded low frequency driver and a 1” high frequency driver on a 40ºH x
70ºV dispersion HF horn in an optimally tuned enclosure. These high grade components are
matched with a third order passive crossover network to ensure a seamless transition between the
HF and LF devices.
The crossover network incorporates a two-stage thermal overload protection system which
prevents damage to the high frequency driver, reacting instantly to large transient peaks while still
allowing wide dynamic range to be maintained. Although the protection system is transparent at
normal operating levels, as the level increases the signal is gradually and imperceptibly
compressed once the critical threshold has been reached.
The cabinet is constructed from 15mm (5/8”) birch plywood, screwed and glued together for
maximum rigidity. Its symmetrical shape allows the monitor to be inverted and used as left/right
mirror image pairs.
In addition to its primary function as a floor monitor, the TXD-12M is also suitable for front-of-
house applications and can be used with the integral pole mount socket on top of optional 35mm
poles and loudspeaker stands. Two recessed flush handles are provided for easy lifting and
carrying, and eight rubber feet are fitted. A grey powder-coated perforated steel mesh grille
protects the drive units from damage.
A Neutrik Speakon NL4MP connector is located at each end of the cabinet on recessed panels,
providing input and parallel link connections to additional TXD series monitors.

user manual
TXD series
TXD series manual
page 9
SYSTEM REQUIREMENTS
TXD series enclosures are passive loudspeaker systems. This means that they require only one
amplifier channel for correct operation, the frequency splitting between the low frequency driver
and the high frequency driver or mid and high frequency driver being accomplished by the
internal passive crossover network built into each enclosure.
If low frequency enclosures are used to extend low frequency response, this can be achieved
without the need for additional amplifier channels or external electronic crossovers. All TXD series
low frequency enclosures are equipped with internal low pass crossover networks which filter mid
and high frequencies away from the bass speaker. Therefore a full range system consisting of, for
example, a TXD-121 and a TXD-115 can be powered from a single amplifier as shown below,
thereby saving the expense of additional amplifiers and external crossovers.
TXD-121
TXD SERIES
TXD-115
TXD SERIES
TXD-121
TXD SERIES
TXD-115
TXD SERIES
AMPLIFIER
+Pin 1 GND.
Pin 3
Pin.2.
__
+
Channe l BOutput Link Input Input
+
Pin 1 GND.
_
+
Pin2
Pin3
-
Channel ALi nk Ou tput
1. Connect the amplifier output to the Speakon INPUT socket on the bass enclosure.
2. Then connect an additional speaker cable from the LINK socket on the bass cabinet to the
INPUT socket on the full range cabinet. Speakon pin connections are shown below.
Back Front
1+
2+
2-
1-
Speakon Pin Wiring
Pin 1+ Positive
Pin 1- Negative
Pin 2+ No Connection
Pin 2- No Connection

user manual
TXD series
TXD series manual
page 10
Bi-amplified operation
TXD series two-way loudspeakers can also be operated in bi-amplified mode together with any of
the available bass enclosures, in order to give enhanced audio performance and greater overall
sound pressure level. In this case one amplifier will power the full range loudspeakers, while
another is required to power the bass cabinets. An external 2-in, 4-out crossover, such as the LMS-
D4 digital loudspeaker management system, is required with a crossover frequency at 150Hz.
To operate TXD systems in bi-amplified mode, it is necessary to bypass the passive crossover in
the bass cabinet. To do this, undo the four screws holding the pole mount socket in place, and
firmly pull the pole mount out of the cabinet together with the passive crossover selection wiring.
In the case of the TXD-215, remove the lower side pole mount.
BI-AMP
(BY-PASS PASSIVE
CROSSOVER) PASSIVE
Mode selection is determined by the position of the wire links on the connector block. To bypass
the internal passive crossover, connect the yellow link wire from the red to the black as shown in
the diagram above and replace the pole mount in the cabinet.
TXD-121
LIMIT
-24
MUTE RS-232
<BACK NEXT >
MENU ENTER
SCROLL
CLIP
A B 1 2 3 4
_
+
-
AMPLIFIER
ChannelB
+
_
Pin1 GND.
Pin.2.
Pin3
Outpu t Link Input Input ChannelA
Pin1 GND.
+
Pin3
Pin2 _
Link
+
Outpu t
_
+
+
Pin1 GND.Pin1 GND. AMPLIFIER
+
_
Pin.2.
Pin3
Pin2
Pin3 _
-
ChannelBOutput Link Input Input ChannelALink Output
+
TXD-121
TXD-115 TXD-115
LMS D4
HIGH
LOW

user manual
TXD series
TXD series manual
page 11
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:
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 one within its ratings.
Equalisation
TXD series enclosures are designed to provide smooth and even frequency response. They do not
need excessive amounts of external equalisation to overcome the sonic deficiencies often found in
many lesser designs.
In order to compensate for the room acoustics, TXD series enclosures require 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 loudspeakers 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. It is good practice to use as little equalisation
as possible, aiming to cut frequencies rather than adding large amounts of boost.
Dispersion
TXD series enclosures are designed to provide relatively wide (70°) horizontal coverage. This
allows the majority of live sound applications to be covered with single enclosures placed
individually to take advantage of this performance feature, for example either side of a stage in a

user manual
TXD series
TXD series manual
page 12
pub or small club environment as shown below. For best results the loudspeakers should be either
mounted on tripod stands or supported on straight poles on top of TXD series bass enclosures. In
order to optimise the sound coverage, point the loudspeakers inwards slightly, such that the
centre lines intersect at a distance approximately equal to twice the width of the stage.
STAGE
It is possible to array TXD series loudspeakers in order to achieve wider horizontal coverage and in
these applications it is recommended that the cabinets be placed such that the trapezoidal sides
are touching to ensure that the appropriate splay angle is observed. For guidance when designing
a sound system, a 70º horizontal polar pattern equals an angle of 35º either side of the centre line
at which the sound pressure level is 6dB down with respect to centre, (averaged over the whole
frequency range of the loudspeaker). Thus a 40º vertical dispersion gives an angle of 20º above
and below the horizon.

user manual
TXD series
TXD series manual
page 13
SYSTEM CONNECTIONS
The following diagrams illustrate several TXD series applications, ranging from a simple live
performance system of just two loudspeakers to a multi-zoned nightclub system
Passive two way system
Connect a second pair of loudspeakers in parallel (shown with dotted lines) if required, using the
link connections on the rear panel.
Passive full-range system with subs
Connect the power amplifier first to the bass cabinets, and then to the two-way loudspeakers
using the link connections.

user manual
TXD series
TXD series manual
page 14
Passive full-range system with subs
Connect to the bass cabinets as in the example above.
Passive full-range system with subs

user manual
TXD series
TXD series manual
page 15
Live performance monitor system
Take auxiliary feeds from the mixer via a graphic equaliser to two separate channels of a power
amplifier. Connect a second unit in parallel to form mirror-image pairs.
Bi-amplified system with subs

user manual
TXD series
TXD series manual
page 16
Club system with multiple zones

user manual
TXD series
TXD series manual
page 17
MOUNTING AND FIXING
A versatile range of mounting hardware is available that
allows enclosures to be used in a variety of ways, in either
mobile sound reinforcement applications or permanent
installations.
A pole mount / tripod stand fitting
A pole mount / tripod stand fittingA pole mount / tripod stand fitting
A pole mount / tripod stand fitting is fitted to the bottom of
the TXD-121 and TXD-151 full range cabinets. Use this pole
mount facility with either optional Turbosound PA-60, PA-90
or PA-100 35mm diameter poles, or conventional
loudspeaker tripod stands. Doing so will raise the
loudspeaker above the heads of an audience, providing better
sound coverage from a single enclosure. A matching pole
mount socket is provided on the top of the TXD series low
frequency enclosures to accept the various poles.
All TXD series cabinets, including low frequency enclosures, can be rigged in permanent
installations using optional M10 shoulder eyebolts
optional M10 shoulder eyeboltsoptional M10 shoulder eyebolts
optional M10 shoulder eyebolts. The top of each cabinet is provided with two
internal threaded rigging points, and a further rigging point is provided on the back panel which is
used to vary the amount of downward angle. As supplied, these rigging points are fitted externally
with M10 countersunk slot-head screws. To facilitate rigging of the enclosure simply remove these
M10 screws and replace them with M10 x 18mm shoulder eyebolts using a suitable thread locking
compound to avoid the possibility of loosening (please refer to Appendix C: Use of thread locking
compounds at the back of this manual). Note:
Note:Note:
Note: Eyebolts must have a thread length of at least
18mm (3/4”).
NOTE:
NOTE:NOTE:
NOTE: The rigging points are designed to suspend single enclosures only. There is no facility to
hang an additional cabinet below a flown TXD series enclosure.

user manual
TXD series
TXD series manual
page 18
IMPORTANT:
IMPORTANT:IMPORTANT:
IMPORTANT: 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
NOTENOTE
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 TXD series enclosures 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.
CHOOSING THE BEST LOCATION
When using any loudspeaker 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).

user manual
TXD series
TXD series manual
page 19
MAINTENANCE
If any of the drive units in your TXD series cabinet should cease functioning and need a
replacement recone or diaphragm, you are advised to remove the faulty unit from the cabinet and
send it to a professional service centre authorised to repair Turbosound loudspeakers.
Removal of the low frequency driver(s)
The perforated steel loudspeaker grille is held in place under tension only, fitting into slots at
either side of the baffle. There are no screws or other fixings holding the grille in place. Lay the
cabinet on its back and, using two small screwdrivers inserted through the mesh of the grille,
firmly pull the grille away from the slot at one side of the baffle until it is free. Set the grille aside
for later re-assembly.
Undo the four screws holding the driver(s) in place and carefully lift it out and away from the
cabinet. Make a note of the driver polarity for later reconnection. Disconnect the cables from the
drive unit and completely remove the driver from the cabinet.
To reinstate the driver(s) simply reverse the above procedure, making sure you observe the
correct polarity when reconnecting the cables back into the terminals of the drive units.
Removal of the high frequency compression driver
Remove the loudspeaker grille as described above and set the grille aside for later re-fitting.
Remove the horn/driver assembly by unscrewing the four screws holding the flange in place. Lift it
out and away from the cabinet. The high frequency driver can now be disassembled from the HF
horn.

user manual
TXD series
TXD series manual
page 20
Appendix B
Technical Specifications
TXD-121 TXD-12M TXD-151
Dimensions
(H x W x D)
553mm x 411mm x 352mm
(21.8” x 16.2” x 13.9”)
435mm x 533mm x 288mm
(17.1” x 21.8” x 11.3”)
652mm x 465mm x 423mm
(25.7” x 18.3” x 16.7”)
Net weight 20kg (44lbs) 18kg (39.6lbs) 28kg (61.6lbs)
Components 1 x 12” LF driver
1 x 1” HF compression driver
1 x 12” LF driver
1 x 1” HF compression driver
1 x 15” LF driver
1 x 1” HF compression driver
Frequency response 60Hz – 20kHz ±4dB 65Hz – 20kHz ±4dB 45Hz – 20kHz ±4dB
Nominal dispersion 70°H x 40°V @-6dB pts 40°H x 70°V @-6dB pts 70°H x 40°V @-6dB pts
Sensitivity 97dB, 1 watt @ 1metre 97dB, 1 watt @ 1metre 99dB, 1 watt @ 1 metre
Power handling 300 watts r.m.s.
600 watts program
300 watts r.m.s.
600 watts program
300 watt r.m.s.
600 watts program
Maximum SPL 122dB continuous
128dB peak
122dB continuous
128dB peak
124dB continuous
130dB peak
Construction 15mm (5/8”) birch plywood 15mm (5/8”) birch plywood 15mm (5/8”) birch plywood
Grille Powder coated perforated
steel
Powder coated perforated
steel
Powder coated perforated
steel
Connectors (2) Speakon NL4MP wired
pin 1+ positive,
pin 1- negative
(2) Speakon NL4MP wired
pin 1+ positive,
pin 1- negative
(2) Speakon NL4MP wired
pin 1+ positive,
pin 1- negative
Due to continuing product improvement the above specifications are subject to change.