User manual

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iLM8 User Manual
Introduction
Broadcasters need a solution to effectively measure, and ultimately control the abrupt changes in
loudness that sends viewers diving for their remote controls during commercial breaks and action
scenes. DaySequerra’s iLM8 Intelligent Loudness Meter measures perceived loudness of up to eight
channels of program audio using the industry-standard ITU-R BS.1770/1 loudness measure, along with
the DTS-Neural Loudness Measure (NLM) algorithm and the weighted intensity measures Leq(A),
Leq(B), Leq(C) and Leq(M).
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. Current audio level meters measure the
level of audio signals expressed as the amplitude of the signal - either the RMS (root mean square)
voltage of an electrical signal or the sound pressure of an acoustical signal. Neither of these
measurements, although widely accepted, provides accurate indications of how viewers will perceive
the loudness of the audio programming.
The DTS NLM algorithm uses a perceptual model of human hearing to more accurately detect spectral
and density differences, inter-channel relationships and temporal overlaps in any audio content,
resulting in a more accurate perceived loudness measurement over time. This proprietary algorithm
was developed by after extensive research into human hearing and perceived loudness.
The iLM8 measures the perceived loudness of eight channels of program audio and displays the results
in an easy-to-read numerical format with a moving average over time, eliminating the variations with
engineers interpreting traditional VU or PPM indicators (neither of which can measure perceived
loudness).
To improve system reliability and up-time, iLM8 uses a robust DSP-based processing platform rather
than a PC-based approach to completely avoid broadcast disruptions caused by operating system
lockups. The iLM8’s built-in high-performance headphone amplifier allows monitoring of any two user-
selected output pairs even in noisy background environments. An Ethernet interface provides long-term
logging and field software updates capability. The exclusive DaySequerra Mix Monitor provides instant
positive feedback if the audio is within target range. An optional factory-installed HD/SDI module will
allow for measurement of 8 channels of program audio from group 1 or group 2 with user specified
mappings within the group.
Whether pre-screening content at an ingest point or keeping tabs on the output of a broadcast air-
chain, iLM8 is your key to reduce viewer complaints and improve overall audience satisfaction.