DK-Technologies MSD100C-Loudness User Manual

Revision 0.11. - 190409

[Users Guide]

[Users Guide]

MSD100C-LOUDNESS

Applies to software version: 5.25

Copyright© 2005 - 2009 DK-Technologies A/S

interstage

Phistersvej 31, 2900 Hellerup, Danmark

Telefon [phone], fax [phone]

www.interstage.dk

- pro audio with a smile

Trademarks

Adobe and the Adobe Reader are either registered trademarks or trademarks of Adobe Systems Incorporated in the United States
and/or other countries.

Index

1 INTRODUCTION.............................................................................................................................3

2 About the ITU BS.1770 Loudness Measurement..............................................................................4

3 The Main Screen................................................................................................................................5

4 Configuring the MSD100C-LOUDNESS.........................................................................................5

5 Operating the MSD100C-LOUDNESS.............................................................................................7

Appendix A Specifications..........................................................................................................8

DK-Technologies A/S
Marielundvej 37D
DK-2730 Herlev - Denmark

Phone: [phone]
Fax: [phone]

www.dk-technologies.com - [e-mail]

1 INTRODUCTION

Congratulations! By purchasing a Master Stereo Display (MSD) from DK­Technologies you have decided to actually "see what you hear!" We are certain
that your Master Stereo Display will prove an invaluable tool in your daily work.

The MSD100C-LOUDNESS is a dedicated Loudness meter that measures
loudness according to the ITU BS.1770 recommendation.

The meter has 1 AES-3 input and 1 stereo pair of analogue inputs. It also has 1
VGA output for connection with an external VGA monitor.

1.1 The formatting of this manual

[GATE] – This is a key in a menu that can be pressed.

In the headlines above the sections of this manual are images of keys and menu
items shown on the LCD screen. These images represent the necessary key
order to reach a particular function from the start-up menu.

2 About the ITU BS.1770 Loudness Measurement

The ITU Recommendation BS.1770 specifies the algorithms to measure audio
programme loudness. The RLB-LU application implements these algorithms to
display the loudness of a Stereo signal as well as for a Surround Sound Signal.
(The MSD100C-LOUDNESS can only measure Loudness for a stereo signal)

Different working modes of the meter are selectable, including:

· Fast mode for real time control of loudness.

· Integrating mode for measuring the loudness of a recorded section or the
complete recording.

2.1 Applications

There are many applications, where it is necessary to measure and control the
perceived loudness of audio signals.
Examples of this includes television and radio broadcast applications, where the
nature and content of the programme material changes frequently. In these
applications the audio content can continually switch between music, speech
and sound effects. Such changes in the content of the programme material can
result in significant changes in subjective loudness.

Moreover, various forms of dynamic processing are frequently applied to the
signals, which can have significant effect on the perceived loudness of the
signal.
The matter of subjective loudness is also of great importance to the music
industry and in the production of commercials, where dynamic range processing
is commonly used to maximize the perceived loudness.

2.2 Loudness Measurements

It is thus well recognized that loudness metering is required for broadcast
applications.
The algorithm recommended by ITU and implemented in the RLB-LU application
is based on an extension of the Leq(RLB) algorithm to cover stereo and
multichannel audio signals. In this algorithm the Leq is an unweighted mean­square measure, while the RLB involves a high pass frequency weighting curve
referred to as the Revised Low-frequency B-curve.

Loudness is a perceptual property of an audio signal, when it is reproduced
acoustically. It is a complex non-linear function of amplitude, frequency and
bandwidth.
Present audio level meters measure the level of audio signals expressed as the
amplitude of the signal - either the rms voltage of an electrical signal or the
sound pressure of an acoustic signal.
This level is an objective property, which is independent of frequency and
bandwidth and is measured linearly in volts, if electrical, or Pascals, if acoustic.
For the purpose of broadcasting, loudness can also be measured as an
electrical property, assuming a fixed electro-acoustic gain for reproduction. This
assumption is the basis for the broadcast loudness meter. The reproduction
level, that has been assumed in the home, is 60 dBA. A level found to be typical
for television viewing at home.

The RLB-LU application has two main operating modes for different purposes:

Fast mode (SLIDE) for instantaneous monitoring of the loudness level. This
mode is used in production, post-production and presentation. The programme
level should be set so that on typical dialogue the meter displays 0 LU on
average.

Integrating mode for a single figure overall loudness. This mode is used for
quality control, mainly at programme ingestion, programme emission and in
post-mortem analysis. The single figure output from this mode allows clear and
unambiguous information for loudness matching and gain setting. This mode
makes it easy to secure consistent loudness over different programmes and
short sequences.

3 The Main Screen

Below is the MSD100C-LOUDNESS main screen.

The main screen consists of 5 different areas.

Area 1 is a phase correlator that measures the phase relationship between the 2
input channels.

Area 2 is a vector scope also known as a goniometer. See section

Area 3 is the bar window that shows each channel and a graphical
representation of the loudness measurement (LU).

Area 4 is numerical presentation of the loudness measurement (LU) and a peak
overload indicator.

Area 5 is the soft key menu. This menu will change depending of the different
situations.

4 Configuring the MSD100C-LOUDNESS

The MSD100C-LOUDNESS has two types of configurations - the normal
configuration and the advanced configuration.

4.1 The normal configuration

The normal configuration is the configuration of the Gate level and the size of
the sliding window in the Fast mode (Slide mode).

4.1.1 Setting the Gate level

If the audio is under the [GATE] level the calculation of the Loudness will stop
and first start again if one of the channels exceeds the [GATE] level. This is
useful when measuring e.g. golf matches and other types of material with
long pauses in the audio.
Use the [] / [] keys to adjust the level. The gate level can be set between

-6dB and -18dB. The default value is -15dB.

1

2

3

4

5

4.1.1 The sliding window size

The sliding window size in the fast mode is the length of time the loudness
measurement is calculating the average.

The sliding window size can be changed by pressing the [SLIDE] key. This also
sets the meter in fast mode.

Use the [] / [] keys to adjust the time. The time can be set between 0
seconds and 9 seconds. The default value is 2 seconds.

4.2 The advanced configuration

Hold the [GATE] key down for about 1 second to enter the Configuration menu.

The small window on the right hand side is the software version. The software
version is good to know if you need to contact customer support.

4.2.1 Input Selection

Press the [AES] the change between the analogue and the AES3 input. If the
marker is green the AES3 input is selected. The AES3 input is selected as
default.

4.2.2 The Configuration Wizard

Press the [SETUP] key to enter the configuration wizard.

The first step in the wizard is the configuration of the true peak level. This value
indicates at which level the true peak indicator will turn red. The true peak
indicator is the numerical presentation of the loudness. Use the [] / [] keys to
adjust the level. The Peak Level can be set between -2dBFs and -9dBFs.
Default value is -2dBFs.

Press the [NEXT] key to continue the wizard.

The second step in the wizard is the configuration of the RLB-LU reference.
The RLB-LU reference is the 0 LU level compared with dBFs un-weighted.
The level can be tested with a test tone at the same level as the RLB-LU REF
setting and a frequency at 300Hz. Use the [] / [] keys to adjust the level. The
RLB-LU Reference can be set between -15dBFs and -24dBFs. The default
value is -20dBFs.

Press the [EXIT] key to finalise the wizard.

4.2.3 Saving the Configuration

Press the [EXIT] key in the configurations menu to save the changes.

5 Operating the MSD100C-LOUDNESS

The MSD100C-LOUDNESS can work in two different modes – in fast mode
(sliding mode) or in integrating mode.

5.1 Fast Mode (Sliding Mode)

The meter is put in to Fast mode by pressing the [SLIDE] key. This also opens
the window size menu as mentioned in section 4.1.1.
Press the [EXIT] key to return to the main menu. Please note that the marked
on the left side of the [SLIDE] key is now green indicating that the meter is in
fast mode.

5.2 Integrating mode

The meter is put in to Integrating mode by pressing the [INTG] key. This will also
reveal the integrating menu. The integrating menu is shown below.

5.2.1 Starting the Integrating measurement

The integrating measurement is started by pressing the [START]. The numeric
display and the loudness bar will show the loudness when the measurement is
running.

5.2.2 Stopping the Integrating measurement

The integrating measurement is stopped by pressing the [STOP] key. After
stopping the measurement the result can be seen in the numeric display and on
the loudness bar.

Appendix A Specifications

A.1 The loudness specification

The MSD100C-LOUDNESS is conforms with the ITU BS.1770 and ITU BS.
1771 recommendations on how to measure loudness.

A.2 Inputs

The MSD100C-LOUDNESS is equipped with 1 AES3 and 1 stereo pair of
analogue inputs.

Digital input:

The digital input is equipped with a sample rate converter to synchronize the
input to the internal clock.

Sample rate range: 30 Hz to 100 kHz.
Internal sample rate: 48 kHz.
Bit resolution: 24 bits.
Group delay: maximum 1.75 msec.
Passband ripple: ±0.008 dB.
Total harmonic distortion and noise: typical –103 dB at 1 kHz.
Dynamic range: more than 120 dB.
Nominal input impedance: 110 ohm.

Analogue input:

The analogue input is a true transformer balanced input.

Maximum input level: +24 dBu.
Frequency range within ±0.3 dB: 30 Hz to 20 kHz.
Passband ripple: ±0,002 dB.
Group delay: less than 0.82 msec.
Dynamic range, A-weighted: more than 103 dB.
Crosstalk at 1 kHz: less than –96 dB.
Signal-to-noise ratio: typical 93 dB.
Nominal input impedance: larger than 20 kohm.

A.3 Mechanical Specifications

The MSD100C-LOUDNESS is as standard delivered with an U-bracket and a
Base Plate for easy table mount.

Dimensions:

Height: 144 mm
Width: 186 mm (Mounting holes 190 mm)
Depth: 41 mm

MSD Software Manual Appendix A Specifications

A.4 Pin configurations

A.4.1 Utility Connector with RS232 communication

Utility connector with RS232 communication.

Connector type: 9 Pin Female D-Sub.

*)

If connecting to a 9 pin serial port (D-Dub) then pin 2, 3 and 5 must be connected to the same pin numbers on the PC.

(RX and TX should not be switched.)

A.4.2 VGA Connector

The MSD100C-LOUDNESS if fitted with a VGA connector for an external
display.

Connector type: 15 Pin Female High Density D-Sub.

Signal Name Pin number

RS232 TX 2

RS232 RX 3

Ground 5

*)

*)

*)

Signal Name Pin number

Red 1

Green 2

Blue 3

Ground 5

Ground 6

Ground 7

Ground 8

Ground 10

H-Sync 13

V-Sync 14

Appendix A Specifications MSD Software Manual

A.4.3 Audio and Power Connector

The MSD100C-LOUDNESS is fitted with a 25 pin D-Sub connector for the
audio and power connections A breakout cable to XLR connectors and the
power supply are supplied as standard.

Connector type: 25 Pin Female D-Sub.

Signal Name. Pin number.

Analogue Channel 1 Hot 14

View from solder side of the 25 pin
MALE D-Sub connector.

Analogue Channel 2 Hot 15

AES3 Hot 9

Cold 1

Ground 2

Cold 3

Ground 16

Cold 21

Ground 22

Power +Vcc

25

(15VDC)

Ground 12

interstage

Phistersvej 31, 2900 Hellerup, Danmark

Telefon [phone], fax [phone]

www.interstage.dk

- pro audio with a smile