Linear Acoustic LQ-1000 User manual

LQ-1000
Loudness Quality Monitor
With Full-Color Loudness Speedometer™
Plus ITU-R BS.1770-1 and EBU R128 Support
and Optional Dolby® Digital/Plus/E Decoding
User Guide

LQ-1000
Loudness Quality Monitor
With Full-Color Loudness Speedometer™
Plus ITU-R BS.1770-1 and EBU R128 Support
and Optional Dolby® Digital/Plus/E Decoding
User Guide
Release Date: February, 2011
Software Version: 1.00.05 and later
Linear Acoustic Inc.
Phone: [phone]
FAX: [phone]
Web: www.LinearAcoustic.com

Warranty Information
DISCLAIMER OF WARRANTIES: Products manufactured by Linear Acoustic are warranted
against defects in material and workmanship
purchase of date the from
warranty 5-year Alliance Telos standard the under
.THERE ARE NO OTHER IMPLIED OR EXPRESS
WARRANTIES AND NO WAR- RANTY FOR MERCHANTABILITY OR FITNESS
FOR A PARTICULAR PURPOSE.
During the warranty period Linear Acoustic Inc. will repair, or at our discretion replace, components
which prove to be defective, provided the unit is returned, shipped pre-paid to us directly with a return
authorization (RA) number clearly marked on the packaging. Please note, this RA number must be
present or package will be refused and returned to sender.
All requests for repairs MUST include the unit serial number to ensure quick and accurate service.
DEFECTS CAUSED BY UNAUTHORIZED MODIFICATIONS, MISUSE OR ACCI-
DENTS, UNAUTHORIZED CUSTOMER REPAIRS, OR ANY FURTHER DAMAGE
CAUSED BY INADEQUATE PACKAGING FOR SERVICE RETURN ARE NOT COV-
ERED BY THIS WARRANTY.
PLEASE SAVE THE SHIPPING CARTON AND ALL PACKING MATERIALS. FAILURE
TO RETURN UNIT IN ORIGINAL SHIPPING CARTON AND PACKING MATERIALS
WILL RESULT IN A CHARGE FOR NEW SHIPPING MATERIALS.
LIMITATION OF PERIOD OF ACTION ON CONTRACT: No action, regardless of form,
arising out of the transactions under this agreement may be brought by buyer, its successors, agents
and/or assigns, more than three years from date of purchase.
LIMITATION OF LIABILITY: It is understood and agreed that Linear Acoustic’s liability whether
in contract, in tort, under any warranty, in negligence or otherwise shall not exceed the cost of repair
or replacement of the defective components and under no circumstances shall Linear Acoustic be liable
for incidental, special, direct, indirect or consequential damages, or loss of use, revenue or profit even
if Linear Acoustic or its agents have been advised, orally or in writing, of the possibility of such damages.
This product contains Audyne technologies and is manufactured under license.
This product optionally contains Dolby Digital (AC-3), Dolby Digital Plus (E-AC-3), and Dolby E
decoding and is manufactured under license from Dolby Laboratories, Inc. The decoder contains con-
fidential unpublished works and is protected by US and foreign patents and is copyright 2007 Dolby
Laboratories, Inc.
Linear Acoustic, the “LA” symbol, and UPMAX, LQ-1000, AERO.qc, AEROMAX, CrowdControl,
UPMAX, and UPMAX-II are trademarks or registered trademarks of Linear Acoustic Inc., all other
trademarks remain the property of their respective owners.

Linear Acoustic LQ-1000 User Guide
v
Table of Contents
List of Figures..........................................................................................................................................vii
Chapter 1: Introduction...................................................................................................................5
1.1 Principles of Operation..........................................................................................5
1.2 Reference Levels and Line Up Features..............................................................6
1.3 Powering Up and Shutting Down........................................................................6
1.4 Reset and Upgrades................................................................................................7
1.5 Warranty and Feedback .........................................................................................7
Chapter 2: Connections and Quick Setup.......................................................................9
2.1 Unpacking and Inspection ....................................................................................9
2.2 Installation ...............................................................................................................9
2.3 Rear Panel ..............................................................................................................10
2.3.1 Connection Ports .................................................................................10
2.4 Quick Setup Notes ...............................................................................................11
2.5 Password Programming.......................................................................................12
Chapter 3: Applications and Use ..........................................................................................13
3.1 Measuring Loudness.............................................................................................14
3.1.1 ITU-R BS.1770 .....................................................................................14
3.1.2 EBU Recommendation R128.............................................................15
3.2 Measurement with the LQ-1000 ........................................................................17
3.2.1 Display Colors ......................................................................................18
3.3 Scaling with the LQ-1000....................................................................................19
3.4 Application Examples ..........................................................................................20
3.4.1 Discrete Baseband AES ......................................................................20
3.4.2 Discrete Baseband SDI .......................................................................21
3.4.3 Dolby E Decode to Baseband............................................................22
3.4.4 Live Production....................................................................................23

Linear Acoustic LQ-1000 User Guide
vi
Chapter 4: Detailed Operation.................................................................................................25
4.1 Main Menu Navigation ........................................................................................25
4.1.1 System Info Menu................................................................................25
4.1.2 System Options.....................................................................................26
4.1.3 Test Tones.............................................................................................29
4.1.4 GPI Setup..............................................................................................30
4.1.5 Record Audio to USB..........................................................................30
4.1.6 Time and Date Settings .......................................................................30
4.2 Fullscreen Menu Navigation ...............................................................................31
4.2.1 Fullscreen Mode Adjustments:...........................................................31
4.2.2 ITU Meter Options:.............................................................................32
4.2.3 EBU Meter Settings .............................................................................33
4.2.4 RTA Options: .......................................................................................33
Chapter 5: Troubleshooting.......................................................................................................37
5.1 Problems and Possible Causes............................................................................37
5.1.1 Unit won’t power on............................................................................37
5.1.2 The “LA” symbol is flashing red .......................................................38
5.1.3 Output Audio Clicks and Pops ..........................................................38
5.1.4 Audio Sounds Strange .........................................................................38
5.1.5 Audio Fixed by Re-boot......................................................................38
5.1.6 Audio Has Artifacts .............................................................................38
Chapter 6: Specifications............................................................................................................39

Linear Acoustic LQ-1000 User Guide
vii
List of Figures
1-1 Audio Block Diagram .........................................................................................................................6
2-1 Rear Panel ...........................................................................................................................................10
3-1 Block diagram of ITU-R BS.1770 multichannel loudness algorithm ........................................14
3-2 Responses of the pre-filter ................................................................................................................15
3-3 Fullscreen ITU mode display for channels 1-6 .............................................................................17
3-4 EBU Mode screen for channels 1-6 ................................................................................................18
3-5 Comfort Zone (from Riedmiller, et. al.) .........................................................................................19
3-6 LQ-1000 Used for ingest of discrete audio channels ...................................................................20
3-7 LQ-1000 Used for ingest of SDI embedded audio channels ......................................................21
3-8 LQ-1000 used for decode of Dolby E audio and loudness measurement during ingest .......22
3-9 LQ-1000 used for live production ..................................................................................................23
4-1 Locked Main Screen (left); Unlocked Main Screen (right) ..........................................................25
4-2 System Info menu ..............................................................................................................................26
4-3 System Options menu (left) and Preferences menu (right). ........................................................29
4-4 Top of Fullscreen Mode screen........................................................................................................31

Linear Acoustic LQ-1000 User Guide
viii

Linear Acoustic LQ-1000 User Guide
5
Chapter 1: Introduction
The Linear Acoustic LQ-1000 Loudness Quality Monitor is an all-in-one unit that com-
bines standard ITU-R BS.1770 loudness measurement with unique display techniques to
simplify loudness measurement. Values are displayed graphically so that no interpretation
is required better ensuring that all operators will have the same high quality result.
The LQ-1000 provides the following features:
• Triple ITU-R BS.1770 loudness meters with individual integration time adjustments
(i.e. Slow, Medium and Fast) with numeric and logical color graphic indication of re-
sults: Blue=too quiet, Green-Yellow=good (spans 15dB comfort zone), Red=too loud
•NEW: Simultaneous EBU R128 metering with relative gating and Loudness Range
(LRA)
• Quad meter engines for simultaneous measurement of 5.1+2 ITU and EBU
•NEW: Session and 7.5 day Weekly logging with results in graphable CSV format
• Oscilloscope and third/sixth octave real-time spectrum analyzer (RTA)
• Standard HD/SD-SDI I/O with access to all 16 audio channels and VANC metadata
•VGAoutput
• Headphone output with plenty of level for quiet content
•NEW: Scaling “Apply” function allows simple gain shifting of up to +/-24dB to be
applied to input audio with safety limiter to prevent overload; automatic calculation of
target vs. measured difference then manual apply
• Optional redundant power supplies
• Optional built-in dual Dolby Digital/Dolby Digital Plus/Dolby E decoding
1.1 Principles of Operation
Figure 1-1 shows the internal audio path of the LQ-1000. It should be noted that this dia-
gram is a general representation of signal flow. Please consult the appropriate section of
this manual for specific functionality.

Linear Acoustic LQ-1000 User Guide Introduction
6
Figure 1-1 Audio Block Diagram
1.2 Reference Levels and Line Up Features
The LQ-1000 is designed to support a standard reference level of -20dBFS via its digital
inputs. The LQ-1000 Plus contains a host of built in signal generation capabilities that are
useful for both level calibration of downstream equipment, and for channel identification.
Please see Chapter 4 for detailed information.
1.3 Powering Up and Shutting Down
With the unit plugged in to a valid AC power source, press the Left, Up, and Right buttons
around the rotary encoder. The Linear Acoustic logo blue LEDs will illuminate first and
the unit will then begin booting.
Shutting down is exactly the same: press the Left, Up, and Right buttons. The screen will
show the shutdown sequence, then will then go blank. A few seconds later, the Linear
1/2
3/4
5/6
1/2
3/4
5/6
7/8 7/8
ETHERNET
Control
ETHERNET
Metadata
RS-485
Metadata
Relay Bypass
8
L
R
Headphone
Output
HD/SD-SDI
De-embed
HD/SD-SDI
Input
VANC MD
AES/SDI/SIMM
HD/SD-SDI
Out
HD/SD-SDI
Embed
Dolby E/AC-3
Decode SIMM
(opt)
8
AES/SDI/SIMM
AES/SDI/SIMM
SIMMDecoder
Input: any AES
or SDI Source
Input Gain
-24 to +24
dB
2.0 (7/8)5.1 (1-6) 5.1 vs. 2.0
Main
Inputs Main
Outputs
Relay Bypass
Linear Acoustic LQ-1000 Block Diagram
(S/WVersion1.00.05)
Headphone
Select
AES/SDI/SIMM
Input Gain
-24 to +24
dB
Downmix
Headphone
Mono/Stereo D-to-A
Converter
5.1 Oscilloscope
(“Input”) 2.0 Oscilloscope (“Output”)
RTA
EBU Mode (1-6) EBU Mode (7/8)

Linear Acoustic LQ-1000 User Guide Introduction
7
Acoustic logo backlight will go off and the unit is now powered off.
If there is a need to bypass the unit (LQ-1000 Plus), the best way is via Master Bypass in
the System Settings menu.
1.4 Reset and Upgrades
To reset the unit, simply follow the power off procedure above, then power back on.
For software updates, the factory will provide instructions and an update file that must be
copied to the USB device supplied with the unit.
WARNING: Do not connect any devices other than the supplied USB thumb drive to
the USB connector on the rear panel without specific instructions from the factory!
1.5 Warranty and Feedback
Please take a moment to fill out and return the warranty card included with the unit and
drop it in the mail. This will enable us to contact you if there are any software or documen-
tation issues. Also, we are very interested in your feedback. This unit was designed based
on input gathered from many broadcast and post production engineers and it will evolve
further thanks to ongoing suggestions and comments from users. We look forward to
hearing from you.

Linear Acoustic LQ-1000 User Guide Introduction
8

Linear Acoustic LQ-1000 User Guide
9
Chapter 2: Connections and Quick Setup
This chapter covers all required connections for the LQ-1000.
2.1 Unpacking and Inspection
Before unpacking the unit, inspect the outer carton for shipping damage. If the carton
shows damage, inspect the unit in those areas. Please save the carefully designed shipping
carton and packing materials. In the unlikely event that the unit needs to be returned to the
factory, alternate cartons or packing materials may not be adequate and can cause damage
not covered by warranty.
The following essential items are provided with the unit:
• Bag containing:
• One or two IEC power cords (style matches country of order);
• USB Thumb Drive for software updates
• this manual, and a small piece of SWAG
• Warranty information: Please fill out and return the warranty card to Linear Acoustic
to ensure your software and documentation are kept up to date.
2.2 Installation
LQ-1000 installation requires:
• two standard rack space units with ADEQUATE VENTILATION (the unit vents
from the front side slots;
• standard 75-Ohm BNC cables for digital signal connections;
To connect to digital equipment with 110-Ohm XLR connectors, use impedance-
matching transformers (available from Canare, Neutrik and other manufacturers).
• Proper selection of reference. The unit will default to internal 48kHz, but for proper
timing should be set to AES 1, AES Ref or SDI (AES Ref is only available on the LQ-
1000 Plus and units shipped since February, 2011).

Linear Acoustic LQ-1000 User Guide Connections and Quick Setup
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2.3 Rear Panel
The rear panel of the LQ-1000 contains its electrical I/O.
2.3.1 Connection Ports
All of the LQ-1000’s connections are on the rear panel and are described in detail below.
See Chapter 6: Specifications for specific pinouts.
Figure 2-1 Rear Panel
•Main In: Connect the 48kHz PCM signals to these inputs. The input channels are ar-
ranged as follows: 1/2 = Left front/Right front, 3/4 = Center/LFE, 5/6 = Left sur-
round/Right surround. 7/8 is for an additional +2 program, or can be left
unconnected and an internal downmix can be created.
NOTE: Appropriate reference must be selected for proper operation.
•Main Audio Output: Main 48kHz processed digital audio outputs with same channel
configuration as the inputs on 1-6. The output of the extra stereo +2 program is avail-
able on 7/8 or a compatible LtRt downmix of the main program can be selected.
•Metadata I/O: RS-485 connection accepts the metadata output of any Dolby equip-
ment (DP572, DP570, etc...) or any Dolby-compatible metadata source. Metadata is
currently only used for limited display in the “System Info” menu.
•SDI Input: Any of the 16 possible audio channel from an applied HD/SD-SDI signal
can be de-embedded and used in place of or along with AES inputs. This can be se-
lected in the System Options->I/O Options menu on a pair-by-pair basis.
•SDI Output: Up to 16 audio channels, including the Main outputs and audio channels
present in the applied SDI signal can be re-embedded. Channels in the SDI stream can
also be passed through in a bit-accurate manner, allowing pre-encoded Dolby E or AC-
3 bitstreams to pass untouched. AES outputs remain active in parallel with embedded
audio.

Linear Acoustic LQ-1000 User Guide Connections and Quick Setup
11
•GPI/O: Used to remotely control meter Start/Stop, Apply, Reset, and Next Screen.
These inputs are in parallel with the front panel F1-F4 buttons.
•ETHERNET: Automatically senses 100 or 1000BASE-T Ethernet connectivity for
NTP time service. The LQ-1000 has DHCP enabled and the unique MAC address is
displayed in the System Info menu. Using the MAC address, a facilities network router
can be programmed to assign a specific IP address to the LQ-1000.
•Future: Extra RJ-45 connector for future I/O use.
•USB: Used for software updates via factory instruction. Please Do Not connect any
USB devices to this connector without factory guidance as this may affect the perfor-
mance of the unit.
NOTE: Please do not connect anything to the USB connector without specific in-
structions from the factory. Permanent damage can occur!
2.4 Quick Setup Notes
The Linear Acoustic LQ-1000 is configured at the factory and is ready to go on the air after
making the proper input and output connections and determining if upmixing is desired.
• Select appropriate reference from the System Options->I/O Options menu (AES Ref,
AES 1, SDI, or Internal 48kHz) and make sure the selected reference is applied to the
unit. If reference is missing, the “double L” signal in the upper right corner of the
screen will flash red. For proper operation it should not be flashing.
• Apply audio sources to Main AES inputs and/or SDI Input.
• On a pair-by-pair basis, select the inputs to the processor in the System Options->I/O
Options menu.
• You should see input audio on the top left thumbnail input meters, and you should
also have audio output on the Main AES outputs.
• Pressing the “Prev.” button will enter the Main Menu screen and will show Input and
Output audio on larger scaled meters. Re-enter the full screen mode by highlighting
the menu selection and pressing “Next”.
• In Full Screen mode, press the right “Next” button to cycle through the available me-
ters: 5.1, 2.0 (7/8), Mon +7/8 (5.1 vs. 2.0), Input Oscilloscope, Output Oscilloscope,
RTA.

Linear Acoustic LQ-1000 User Guide Connections and Quick Setup
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The best way to learn the unit is to explore the different settings with audio applied and a
copy of the menu tree. There are many different ways to use this flexible unit and the menu
system will quickly become familiar with just a bit of use.
2.5 Password Programming
After setup, users may wish to password-protect the LQ-1000. This will prevent unauthor-
ized or accidental changes to the settings, however please do not forget the password!

Linear Acoustic LQ-1000 User Guide
13
Chapter 3: Applications and Use
The Linear Acoustic LQ-1000 Loudness Quality Meter was designed to provide all of the
necessary metering tools to allow for proper loudness measurement and human-assisted
control. To recap and expand on the features listed in Chapter 1:
• Loudness Speedometer™ for display of Target Loudness, Maximum Loudness, Max-
imum Peak, and four speeds of Current Loudness
• Triple ITU-R BS.1770 loudness bargraph meters with individual integration time ad-
justments (i.e. Slow, Medium and Fast) with numeric and logical color graphic indica-
tion of results:
• Blue = too quiet
• Green/Yellow = good (spans the ~15dB comfort zone)
• Red = too loud
•NEW: EBU R128 metering with relative gating and Loudness Range (LRA)
• Quad meter engines for simultaneous measurement of 5.1+2 ITU and EBU
•NEW: Session and 7.5 day Weekly logging with results in graphable CSV format
• Front panel Start/Stop and Reset controls, also GPI controllable
• Headphone output with plenty of gain and drive capability
• VGA output for remote monitor
• Multichannel manually applied gain scaling of input audio +/-24dB with protection
limiters to prevent overload
• Optional auto-sensing Dolby Digital/Plus/E decoding
There are myriad application for this flexible tool. The basic idea behind this meter is to
enable better content creation and adjustment as early as possible in the production chain.
Leaving it to even a smart transmission processor at the end will affect the original artistic
intent of the program producer.
NOTE: The golden rule is: “Get Loudness Right At Each Stage”

Linear Acoustic LQ-1000 User Guide Applications and Use
14
3.1 Measuring Loudness
Loudness measurement is decidedly different than simply measuring audio levels. This is
because loudness involves human perception and the measurement will therefore not be
objective, like voltage or current, but will instead be subjective. While the mechanics of
how humans hear are fundamentally the same for each person, what they perceive can vary
significantly.
As hearing research has evolved from over many decades, a truly universal method for
quantifying loudness in a repeatable manner was only formulated in the last few years. Un-
til that point, the only methods available combined objective meters like VU and PPM with
the “eyeball average” of an operator. Skilled operators got reasonable good results, but alas
the world is running in short supply of skilled operators.
3.1.1 ITU-R BS.1770
The International Telecommunications Union (ITU) formed a study group to investigate
a better and more universal answer to the question of how to objectively measure loudness.
The result was published as ITU-R BS.1770 and essentially specifies a system that filters,
weights, then power sums audio channels to create a repeatable numeric result. The basic
block diagram for the resulting system is shown below:
Figure 3-1 Block diagram of ITU-R BS.1770 multichannel loudness algorithm
It can be seen in the above drawing that applied multichannel audio is first filtered (by two
separate stages of filtering to be explained below), then are integrated (mean square) to al-
low power summing, which among other things removes the effects of inter-channel phase
difference causing cancellation. Note that the surround channels are boosted by approxi-
mately 1.5dB each before the sum and the LFE channel is not currently included in the
measurement.
The two stages of filtering are used to remove very low frequency information that does
not add to perceived loudness but will skew loudness results, and to apply a shelving high
frequency boost to make up for frequency response changes due to the shape of the hu-
man head. The two filters are shown below:

Linear Acoustic LQ-1000 User Guide Applications and Use
15
Figure 3-2 Responses of the pre-filter to account for acoustic effects of the head (left), and the RLB
high-pass filter (right) combine to produce the so-called K-weighting filter.
The final output of this system is Loudness, K-weighted, with respect to Full Scale, or
dBLKFS. If a 1kHz tone is applied to the L, C, or R inputs of this system, the output will
indicate approximately -3 dBLKFS, and if applied to Ls or Rs will indicate approximately
-1.5 dBLKFS.
The intention of the standard is to measure the loudness of a program over the entire
length of the program. While this works nicely for pre-recorded content, it does not make
for a useful tool for real-time use. One important part of this measurement that is not yet
part of the standard is integration time. The current metering system will produce instan-
taneous results, but these are relatively useless because the resulting measurement varies
too much and “eyeball interpretation” is once again required.
Longer integration times settle the measurement down and produce a value that correlates
better with what a user actually hears and is steady enough to be useful. Scholarly research
by Gilbert Soulodre of the Canadian Research Centre (CRC) and Jeffrey Riedmiller of Dol-
by Laboratories have suggested that a minimum useful integration time is 3 seconds and
that for practical metering a 10 second average is useful. The recent work of the European
Broadcasting Union (EBU) is suggesting that including an even faster value could be help-
ful.
3.1.2 EBU Recommendation R128
The LQ 1000 supports the new EBU R128 recommended practice for loudness metering.
This new mode adds Relative Gating, display of Momentary, Slow, and Integrated loud-
ness, and Loudness Range indication. These measurements are also captured in a Session
log and an always-running 7.5-day Weekly log, all of which can be exported via USB. EBU
mode runs simultaneously with standard ITU mode and all measurements are always avail-
able.

Linear Acoustic LQ-1000 User Guide Applications and Use
16
Note that while some of the readings can be useful for continuous live metering, our early
experience has shown that the best use of EBU mode is on a segment-by-segment basis
where the meter is Started, Stopped, then reset for the next measurement.
The following functions are supported:
• EBU Measurement gate:
• Absolute gate below -70 LUFS (Loudness Units w.r.t. Full Scale) and a gate
with a relative threshold -8 LU below absolute gated loudness level
• Numeric display of overall (integrated) loudness with respect to target to and accuracy
of 1/10th LU (Loudness Unit), controlled by start/stop/reset
• Display of Loudness Range (LRA):
• Measures the variation of loudness on a macroscopic time scale
• Difference between low (10th) and high (95th) percentile loudness distribution
• Display of low (10th), High (95th) and Median loudness from which LRA is derived
• Simultaneous multi-speed bargraphs:
• Momentary - 400msec integration for indicating very fast changes in loudness
• Short Term - 3 second integration for useful indication of loudness changes
• Integrated - Bargraph version of overall loudness (infinite)
• Color change centered on target to indicate loudness "Comfort Zone"
• Logging functions to save measurement data:
• Timestamped (internal clock or configurable NTP connection) CSV files for
direct import to external spreadsheet and graphing software
• Session Log - All readings between Start/Stop, reset for new session
• Weekly Log - All readings for 7.5 days, rolling capture