In Broadcast - December 2019 - 62

62

www.inbroadcast.com | Vol: 9 - Issue 11 | December 2019

InSound

RTW Focus: The Immersive
Sound Analyser
The audio world is going Immersive, and so are we! In this article I'll
talk about the features of our brand new Immersive Sound Analyser...

W

ith new immersive sound
formats such as Dolby Atmos,
the audio world is having an increased
focus on audio formats with a large
number of audio channels.
For us as a metering focused company,
the challenge is to measure and
display all of these channels in a way
that is usable in the many immersive
audio applications, and the Immersive
Sound Analyser is our take on an
instrument that can get you relevant
technical and subjective parameters of
formats such as 5.1.4 or even 7.1.4 in a
fast and intuitive way.
As we wanted to stay as close as
we can to our unique Surround
Sound Analyser, which a lot of audio
engineers are already familiar with,
some of the features are the same, and
to understand more about the details
of the Immersive Sound Analyser, you
might want to read our blog post on
the SSA .
The examples in this article will be
based on a standard 5.1.4 Dolby Atmos
setup.
The Components of the ISA
First, let us have a look at each
individual component of the Immersive
Sound Analyser. There are components
for each of the main and upper layers,
and there is also a component that
shows the relationship between the
layers.
1: 5.1 Main Bed: The Total Volume
Indicator displays the total volume
and balance of the audio material in a
single view.
The lengths of the bar graphs that go
out from the centre show the sound

By Mike Kahsnitz

Immersive Sound Analyser
complete display

pressure level or loudness. The blue,
outlined area shows the 5.1 main
bed signal image including its centre
channel signal.
The white crosshairs is the so-called
Dominance Indicator (DMI) that
shows the position of the subjectively
perceived acoustic focal point.
2: 4.0 Upper Bed: The orange area
shows the volume and balance of the
upper bed.
Our power users will immediately
recognize that the Dominance
Indicator (DMI) crosshairs is tilted
45 degrees and we have done this to
maintain a clear distinction between
the main and upper bed DMIs.
3: The Relation Between the Main
and the Upper Bed: The relationship
between the main and upper beds is
indicated by the size of a white dot,
and as you can see here, the white dot
sits between the main and upper bed
dominance indicators.
The dot is called the Immersive
Dominance Indicator (IDI) and the
position and size of it indicates the
loudness relation between the main
and the upper bed.

A very small dot indicates that there is
audio only in the main bed, and a large
dot indicates there is audio only in the
upper bed.
4: Main and Upper Bed Combined:
Here you see the combination of the
main bed and upper bed, including the
IDI dot. Once familiar with the display,
you get a fast and intuitive overview of
a 5.1.4 signal.
5: Full ISA View: The Immersive
Sound Analyser displays Total
Volume Indicators for both beds
simultaneously, and the position and
height of the dominant signal is shown
by a white dot.
The phase correlation bars display the
phase relation between the different
sources of the selected bed.
Like the phase correlation bars, the
Phantom Source Indicators (PSI) show
relations between each of the channels
in a surround mix of the selected bed.
The perceived position and its height,
the ambient signal (TVI) of the two
beds and the spreading and phase
correlation of a selectable bed can be
displayed simultaneously in one easyto-read view.

Fig 3: The relationship between the main

Fig 1: 5.1 Main Bed View

Fig 2: 4.0 Upper Bed View

Fig 5: Full ISA View

and upper bed is indicated by
the size of a white dot

Fig 4: Main and Upper bed combined
In Broadcast - December 2019

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