Turbosound LMS-D24 User manual

LMS-D24 / LMS-D26
DIGITAL LOUDSPEAKER
MANAGEMENT SYSTEM
USER MANUAL
Turbosound Ltd.
Star Road, Partridge Green
West Sussex RH13 8RY England
Tel: [phone] Fax: [phone]
web: www.turbosound.com
Version 1.0 ©Turbosound 4/05

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QUICK REFERENCE
(LMS-D26 shown)
Display
The LCD displays preset and parameter information. At start up the display shows the default
screen with the memory location and name of the current preset on the lower line of text.
Channel Select Buttons
The currently selected input or output channel is shown in the top left corner of the display.
Pressing the channel select buttons scrolls through the available inputs and outputs. If operating
stereo linked the channel name will indicate the channel association. For example ‘CH A+B’ means
both input A and B parameters.
Edit Select Buttons
The name of the edit parameter is displayed in the bottom left portion of the LCD. Pressing the edit
select buttons moves through the available parameters for the current input or output.
Parameter Encoders
Up to three parameters are shown on the display. The parameter name is shown with its’ current
value below. Where appropriate parameters are grouped according to function for example centre
frequency, width and gain for parametric EQ. Turn an encoder clockwise to increase the value of a
parameter, or anti-clockwise to decrease it. Turning a knob rapidly will cause the action to
‘accelerate’, so the value changes more rapidly.
Mute Buttons
The LED’s next to the mute buttons indicate their current status. Pressing a mute button toggles
between the mute on and off.
Store Button
The unit has 45 memory locations and allows users to set up their own programs. To store a
preset in a location, press the store button and use the encoders to select the memory location and
name the preset. Pressing the store button again completes the task. Pressing any button other
than store during the process cancels the procedure.

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CONTENTS
Quick reference ........................................................................................................................................................ 2
Display..................................................................................................................................................................2
Channel Select Buttons ...................................................................................................................................... 2
Edit Select Buttons ..............................................................................................................................................2
Parameter Encoders............................................................................................................................................ 2
Mute Buttons ....................................................................................................................................................... 2
Store Button.........................................................................................................................................................2
Important Safety Information.................................................................................................................................5
Regulatory Compliance ...................................................................................................................................... 5
Thanks .................................................................................................................................................................. 6
Unpacking the controller.................................................................................................................................... 6
Introduction.......................................................................................................................................................... 7
Features................................................................................................................................................................7
The User Guide ........................................................................................................................................................ 8
Front Panel Functions ......................................................................................................................................... 9
Rear Panel Functions ........................................................................................................................................11
Operating the LMS series controller.................................................................................................................... 12
Starting up ......................................................................................................................................................... 12
Selecting a Factory Preset................................................................................................................................12
Creating a Crossover ........................................................................................................................................ 12
Navigation and Viewing Parameters ..............................................................................................................13
Navigation..........................................................................................................................................................14
Presets ................................................................................................................................................................15
Preset Recall....................................................................................................................................................... 15
Preset Store........................................................................................................................................................ 16
DSP Processing Layout ......................................................................................................................................... 17
Input DSP block diagram..................................................................................................................................17
Output DSP block diagram...............................................................................................................................17
Stereo / Mono Formats..................................................................................................................................... 17
DSP processing ......................................................................................................................................................18
Input Channels................................................................................................................................................... 18
Parametric Equalisation....................................................................................................................................20
High and Low shelving filters ..........................................................................................................................20
Parametric filters ............................................................................................................................................... 20
Output Channels ....................................................................................................................................................21
Gain and Polarity...............................................................................................................................................21
Delay ................................................................................................................................................................... 21
High and Low Pass Filters ................................................................................................................................ 22

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Parametric Equalisation ................................................................................................................................... 23
Limiters............................................................................................................................................................... 24
Routing ............................................................................................................................................................... 24
Utilities .................................................................................................................................................................... 25
Utility functions ................................................................................................................................................. 25
Factory Presets....................................................................................................................................................... 26
EQ and Filter Response Graphs ........................................................................................................................... 27
Technical Specifications................................................................................................................................... 30
Warranty ................................................................................................................................................................. 31
NOTES ................................................................................................................................................................ 32

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IMPORTANT SAFETY INFORMATION
Please read carefully and keep the following instructions and safety information. Heed all warnings
and follow all instructions.
•Do not remove covers. There are no user serviceable parts inside, please refer servicing
to qualified service personnel.
•This equipment must be earthed.
•Protect the power cord from being walked on or pinched particularly at plugs,
convenience receptacles, and the point where they exit from the apparatus.
•Only use attachments/accessories specified by the manufacturer.
•Servicing is required when the apparatus has been damaged in any way, such as the
power supply cord or plug is damaged, liquid has been spilled or objects have fallen into
he apparatus, the apparatus has been exposed to rain or moisture, does not operate
normally, or has been dropped.
Regulatory Compliance
This product complies with both the EMC Directive (89/336/EEC) and the Low Voltage Directive
(73/23/EEC) as issued by the Commission of the European Community.
Compliance with these directives imply conformity with the following European standards:
•EN60065 Product safety
•EN55103-1 Electromagnetic Interference (Emission)
•EN55103-2 Electromagnetic Susceptibility (Immunity)
This product is intended for operation in the E2 (commercial & light industrial) and E3 (urban
outdoors) Electromagnetic Environments.

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Thanks
Thank you for choosing a TURBOSOUND LMS series controller for your application. Please spare a
little time to read the contents of this manual, so that you 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.
We look forward to helping you in the near future.
Unpacking the controller
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.

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Introduction
The Turbosound LMS series of loudspeaker management systems represents the current state-of-
the-art in digital electronics. The LMS-D24/26 are compact and powerful DSP based audio-
processing units designed for use with Turbosound loudspeaker systems and associated bass
enclosures, combining the functions of multiple conventional products in a compact 1U high 19”
rack unit. To achieve this the LMS-D26 has 2 inputs and 6 outputs (the LMS-D24 features four
outputs), which are configured by different factory presets to allow use with a variety of systems.
The units are designed to provide specific equalisation and crossover points aimed at optimising
the performance of these Turbosound loudspeaker systems. In addition, limiters, delays eq, gain,
polarity, and crossover filter controls are accessible to the user in order to match specific operation
environments. The LMS series crossovers are designed for quick setup and adjustment via easy-to-
use front panel controls.
Features
•Minimal signal path design, providing exceptional audio quality with carefully optimised
processing and high performance converters for a full >111dB dynamic range, 96kHz
sampling rate and minimal filtering. Audio-grade capacitors are used in the analogue signal
path.
•Sonically superb ADC / DAC combination; a carefully matched pairing of the best devices
from Burr Brown and Wolfson.
•Newly released family of Analogue Devices SHARC DSP.
•Extended bandwidth; 96kHz sampling frequency provides for a nominally flat response to
40kHz.
•Front panel parameter rotary encoder provides a familiar and easy to use control format
with all filter information displayed simultaneously on a backlit LCD display.

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THE USER GUIDE
This user manual gives a progressively more detailed description of the functions of the
TURBOSOUND LMS-D26 and LMS-D24 loudspeaker management systems. A single page quick
reference guide is provided for those users who are experienced with this type of equipment and
just need to know how to ‘drive’ the front panel.
A detailed explanation of the front and rear panel controls and indicators is contained in the next
section. The final section describes each individual function or feature with annotated images
explaining its use. Where appropriate, the LCD is shown to further elaborate on the unit’s
operation.
To complete the manual a reference section is included, describing the technical performance of
the device complete with graphs of filter responses and details of the
Factory Presets and their
configuration.

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Front Panel Functions
2x 24 character
LCD
Input Signal
Indicators
Store and
Recall buttons
Channel Select
buttons
Parameter Edit
Encoders
Output Mute
buttons
Limiter
Indicators
Edit Parameter
Select buttons
•Input Signal Indicators – A set of three pairs of LED’s indicate signal present, +4dBu and
input clip for both channels. The signal present LED’s operate at approximately –40 dBu,
giving a useful indication of even relatively low input signal levels. The +4 dBu LED’s are
intended to show nominal operating level and can also be useful for setting system gain
structure. Clip LED’s warn the user of input overload and operate at +19 dBu.
•Program Store and Recall – these controls provide access to 45 presets. Pressing the
store button allows the user to name a preset and choose which memory location it will
be held in. Pressing store button again completes the process. The Recall function
operates in a similar way, pressing the recall button allows the user to select which preset
they require, pressing the button for a second time, then confirming, recalls the new DSP
settings. The unit allows the user to set up user programs with full access to all
parameters.
Note that presets cannot be stored or recalled when secure mode is activated.
•Channel Selection Buttons – the currently selected channel is displayed on the top left
hand corner of the LCD. Pressing the channel buttons scrolls through the available input
and output channels and finally through the utility functions and back to the default
screen. If operating a stereo-linked preset the channel name will indicate the channel
pairing. For example ‘A+B’ means both input A and B parameters. The name of the output
will be shown briefly at the top of the display when stepping onto an output.

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•Edit Select Buttons – the currently selected edit parameter is displayed on the bottom left
corner of the LCD. Pressing the edit select buttons moves through the available
parameters for the current input or output.
•Text display – preset, channel, parameter and status information is shown on the 2x 24-
character text display. In most screens the currently selected channel is displayed on the
upper line and the edit parameter on the lower line. To simplify the display and enhance
security, some parameters or parameter pages are omitted when not relevant.
•Parameter Knobs – three velocity sensitive parameter knobs are used to adjust
parameters shown on the display. Up to three parameters are displayed on the screen.
The parameter name is shown above the parameter value in each of the three screen
sections. The parameter knobs have a fixed association with the screen sections; the
rightmost parameter knob adjusts the rightmost parameter and so on.
•Output signal and limiter indication – two LED’s are provided for each output channel.
These show the signal level relative to the limiter threshold. The yellow LED will light
when the signal is 6dB below the threshold and the red warning LED will light when the
limiter threshold is reached.
•Mute buttons and status LED’s – each output has a mute button and associated mute
status LED. Pressing the button toggles the mute on and off.
•
Note that the mute buttons do not function when the Secure Mode is activated.
•Secure Button (on the rear) – a momentary button is fitted behind the rear panel,
between the output XLRs and the RS232 port. When activated, this will disable all the
front panel controls so they cannot affect the signal path, making the unit secure against
tampering. When in secure mode, the indicators still operate normally.
Note that the communications port is still active in secure mode.

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Rear Panel Functions
Power Inlet
Audio Output
Connectors
Serial Comms
Port
Audio Input
Connectors
Secure Mode
Switch
Expansion
Port
•Power Inlet – provides connection to a suitable mains electricity supply using the cable
supplied. The controller has a switch mode power supply that is capable of operating with
a nominal mains voltage of 80 to 240v, 50/60Hz without re-configuration.
•Network expansion port – where a future network card can be fitted.
•Audio Input connectors – these are fully balanced and are wired pin 1 ground, pin 2 hot
and pin 3 cold. The two inputs have pin 1 connected directly to the chassis and feed the
signal processing chains. If an unbalanced source is used, a connection should be made
between the pin 3 ‘cold’ signal and the ground connection of the unbalanced source.
•Audio Output connectors – the processed outputs are impedance balanced, and are
wired pin 1 ground, pin 2 hot and pin 3 cold. An unbalanced input may be driven by by
connecting pin 3 ‘cold’ signal to the ground connection of the unbalanced destination
input. Note that output pin-1’s are ground lifted at audio frequencies but connected to
ground at RF for good EMC performance. The intention being that the amplifiers the
processor is driving should be responsible for the grounding of their input cable shields.
•Communications port connector – the unit may be controlled entirely from another
controller (typically a Personal Computer), running an application that is compliant with
the ObCom standard. Connection will normally be made to the controller via this serial
port connector. This port is also used for updating the firmware in the unit.
Note: The communications port is NOT disabled when the front panel is made secure using the
secure button.

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OPERATING THE LMS SERIES CONTROLLER
Starting up
The unit will energise as soon as power is applied to the IEC inlet; there is no power switch. During
the start up process the firmware application model number and version numbers are displayed
and the outputs are muted until the unit has completed its internal checks. Once the start-up
routines are complete and the unit is ready to pass audio, the DSP signal path will be restored to
the current settings when it was last powered down and the audio signal is gradually ramped up to
its correct level.
Selecting a Factory Preset
There is a library of thirty Factory Presets to suit a range of Turbosound enclosures.
Factory Presets contain some parameters that are fixed and hidden from view; the remainder of
the DSP parameters are available for user manipulation. The number and type of hidden
parameters is dependant on the Factory Preset, typically crossover frequencies, output delay and
some EQ’s are hidden; those settings that are a function of the loudspeaker cabinet design and
should not require adjustment for different applications.
To recall a Factory Preset for a particular cabinet or system, press Recall and use the left hand
parameter knob A to scroll through the available factory preset locations (as indicated by a box
symbol after the preset number). Once the appropriate preset has been selected press recall again,
at which point you will be asked to confirm the action by pressing recall for a third time. This is to
guard against accidental recall of Presets.
Factory Presets are locked so they cannot be over-written. The user can, however, store an edited
version of a Factory Preset in any free preset location.
Details of all the Factory Presets can be found in Appendix A.
Creating a Crossover
In addition to the Factory Presets the unit has two further ‘ Base Presets ’; mono and stereo. These
Base Presets are stored in locations 1 and 2 respectively, they can be used to develop settings for
any loudspeaker combination and are recalled in the same way as the
Factory Presets described
above. These Presets are also locked but the user can name and store their own edited versions in
any free preset location.

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Navigation and Viewing Parameters
(Note: The LMS-D26 is shown in all the following screen shots; however the features and
parameters apply equally to the LMS-D24)
Many of the processing elements in each input and output path have features that may be
controlled by the user, such as gain, frequency or limiter threshold. We call these adjustable
features parameters.
A parameter may be adjusted when it is displayed by turning one of the three-parameter knobs.
Each of the three-parameter knobs is associated with a zone on the display. Adjusting the leftmost
parameter knob will change the value of the parameter showing in the leftmost zone of the display
and so on. Turn a knob clockwise to increase the value of a parameter, or anti-clockwise to
decrease it. The knobs are velocity-sensitive so turning a knob rapidly will cause the action to
‘accelerate’, so the value changes more rapidly.
LMS-D26
In A Freq Width Gain
EQ1 100Hz 1.4Q 0.0dB
abc
cba

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Navigation
The DSP parameters are organised by channel. The currently selected channel is shown in the top
left hand corner of the display. You can navigate between the channels by pressing the channel
buttons. Pressing the channel buttons will scroll through the channels, utilities and back to the
default screen. When using a Preset that is stereo linked, the channel selection will reflect this. For
example ‘1&4’ indicates outputs 1 and 4. When navigating onto an output channel, the usage of
the output, as define in the factory preset, will be shown briefly at the top of the screen.
LMS-D26
Out1 Freq Width Gain
EQ1 100Hz 1.4Q 0.0dB
abc
CHANNEL
EDIT
Pressing the edit navigation buttons gives access to the various pages of parameters available for
each channel. The currently selected page is shown in the bottom left hand corner of the display,
this is omitted on some pages where the function is obvious. The screen shows up to three
(normally related) parameters for a given part of the processing functions on a given channel.
The edit buttons allow you to scroll, in either direction, through the different processing pages for
a given Channel. When you go past the last page, you will be returned to the default page.
The channel buttons allow you to scroll, in either direction, through the input and output channels,
whilst trying to maintain the currently viewed processing block. If the channel you scroll to does
not have the currently viewed processing block, the next one will be shown instead.
NB. When the unit powers-up, the settings will be the same as those when the unit was last
switched off.

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Presets
The device contains a total of forty-five user and Factory Presets . The user cannot overwrite the
basic mono, basic stereo or
Factory Preset programs.
Preset Recall
To select an existing Preset, press the Recall Button so the indicator above it illuminates. Turn
parameter knob A until the required Preset number is shown on the display. Factory presets are
indicated by a box symbol appearing after the preset number. Press the Recall Button again to
activate the Preset. Pressing any other button will cancel the operation.
LMS-D26
Preset Name
Recall 32 My System
abc
SELECT PRESET
TO RECALL
a
RECALL RECALL
Users can develop their own Preset based on one of the basic or
Factory Presets stored within the
device. Once a basic or user Preset has been recalled, a user has complete freedom to adjust any
or all of the parameters.
Factory Presets can be used as the basis for user Presets but they have
some parameters that are predefined as a function of the loudspeaker system. These parameters
are ‘hidden’ from the user, as they should be constant regardless of application.

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Preset Store
To store the current Preset in a user location, press the Preset Store Button so the indicator above
it illuminates. Turn the first parameter knob until the required Preset location number is show on
the display. A Preset name of up to 12 characters in length can be entered using parameter knobs
B and C. Pressing the Store Button again completes the process and stores the Preset. As with
Preset Recall, pressing any other button cancels the operation.
LMS-D26
Preset Name
Store 32 My System
abc
SELECT STORE
LOCATION
a
STORE STORE
cb NAME PRESET
The user can overwrite non-protected Presets only; if an attempt is made to save a Preset in a
location already occupied by a basic or
Factory Preset a ‘LOCKED PRESET’ message is displayed.

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DSP PROCESSING LAYOUT
Input DSP block diagram
Input A Input
LED’s Input Gain Delay 4th Order HPF Low Shelf EQ Six Band PEQ High Shelf EQ
Routing
Input B
SUM - 6dB
NB. Channel B processing is
identical to Channel A but for
clarity it is not shown
Output DSP block diagram
Routing
Delay 8th Order
HPF 8th Order LPF Low Shelf EQ Six Band PEQ High Shelf EQ Output Gain Mute Limiter
Metering
Stereo / Mono Formats
There is only one ‘standard’ layout of the processing blocks, but flexible routing and control linking
allows this layout to be adapted to a wide variety of applications.
There are two ‘Formats’, Mono or Stereo. With the Mono format, all outputs have unique
parameter settings, and all outputs are identical in terms of processing functions and routing
capability. This is the most flexible Format.
Stereo format pairs the inputs and outputs for stereo operation, the parameters of each member of
the pair being identical. The routing of inputs to outputs is fixed. This format is intended for
symmetrical stereo operation, eliminating the need to make identical parameter adjustments for
each channel.
The channel pairing is:
•Left and Right Inputs
•Outputs 1 (routed from L input) and 3 (routed from R input) [1 and 4 for LMS-D26]
•Outputs 2 (routed from L input) and 4 (routed from R input) [2 and 5 for LMS-D26]
•[Outputs 3 (routed from L input) and 6 (routed from R input) – LMS-D26 only]

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DSP PROCESSING
Input Channels
Gain
LMS-D26
In A Gain
0.0dB
abc
a
Knob A: Gain, adjustable in 0.2dB steps from –80 dB to +20dB
Delay
LMS-D26
In A Delay
1.50ms
abc
a
Knob A: Delay, adjustable in variable steps from 0 to 400ms
The delay parameter is adjustable in fine steps at low values; the adjustment becomes
progressively coarser as the value increases. The velocity sensitive Parameter Knobs therefore
provide accurate setting of driver offset delays (typically below 10ms) and rapid setting of longer
system alignment delays.

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High Pass Filter
LMS-D26
In A Freq Shape
HPF 20.0Hz LR24
abc
a b
Knob A: Frequency, out (off), 10.0Hz to 25.6kHz in variable steps
Knob B: high pass filter type
System high pass filtering is provided for the input signal. This is the preferred location for high
pass filtering as it affects all outputs and can therefore improve inter-band phase relationships.
Filter type is selectable from Butterworth, Bessel, Linkwitz-Riley and Hardman. Filter slopes of up
to 4th order or 24dB / octave are provided. Not all filter types are available in all slopes. For
example 18dB / octave Linkwitz-Riley filters do not exist.
The Hardman type filter is always described by its’ order as the filter becomes progressively
steeper rather than following a linear slope so a dB/octave description is not accurate.

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Parametric Equalisation
Eight sections of equalisation are provided, two shelving filters and six fully variable parametric
sections.
High and Low shelving filters
LMS-D26
In A Freq Slope Gain
EQ1 100Hz 12dB 0.0dB
abc
a b c
Knob A: Frequency, 10.0Hz to 25.6kHz in variable steps
Knob B: Slope, 6 to 12dB / octave in 1dB steps
Knob C: Gain, +/-15dB in 0.2dB steps
The frequency is specified as point where the filter deviates by 3dB from the gain value.
Parametric filters
LMS-D26
In A Freq Width Gain
EQ1 100Hz 1.4Q 0.0dB
abc
cba
Knob A, Centre Frequency, 10.0Hz to 25.6kHz in variable steps
Knob B, Width, display selectable, Q or BW (Bandwidth)
BW adjustable from 0.05 to 5 octaves in variable steps
Q adjustable from 14.2 to 0.2 in variable steps
Knob C, Gain, +/-15dB in 0.2dB steps