The new ‘Live Aid’ license for TC’s System 6000 MKII allows for absolute compliance with loudness-based broadcast standards, even under live and OB conditions.
With the Live Aid license, two pristine loudness processing algorithms and a host of new presets become available to System 6000 MKII. Developed for broadcasters covering no compromise live events such as the London Olympics, one System 6000 MKII is now all it takes to upgrade an entire studio or OB truck with low-latency, high-resolution loudness processing for multiple platforms; at the same time metering adhering to American, European or Japanese standards on all outputs. Live Aid includes two powerful algorithms, ALC6 and DMix, as well as a host of presets targeted to the loudness and true-peak requirements of most of the world.
ALC6: Hit the Right Target
ALC6 offers BS.1770 compliant Loudness Correction and True-peak limiting for mono, stereo and 5.1 programs. This low latency, 48-bit resolution processor may be used as a loudness safety belt for easily hitting a -23 or -24 target directly from a live studio or an OB truck. Unlike compression or limiting type of processors, ALC6 only adjusts when needed – the rest of the time, audio is passed untouched.
Keep CALM. Keep R128. Keep TR-B32
For live processing, select the ‘Not Normalized’ profile, and decide whether ALC6 is allowed to add positive gain or not. The adaptive Stridency Reduction parameter brings overly loud content under tight control while leaving normal content untouched, and True-peak limiting on the 5.1 outputs sets a precisely defined upper limit to instantaneous level.
Live Downmix Compliance
Measuring the loudness of a 5.1 program can give significantly different results from measuring a stereo or a mono downmix of the same program. These differences are systematic because measuring loudness according to BS.1770 is insensitive to inter-channel phase differences, while a downmix is not. Tight tolerances on program loudness therefore present a dilemma when it comes to mono or stereo listeners, generally the vast majority of a station’s audience.
ALC6 introduces a new way of dealing with this issue: A 5.1 program may be adjusted based on what it measures in 5.1, or on what it measures using a specific set of downmix coefficients.
ALC6 also helps getting a higher audio quality and more headroom out of AC3 data reduction. The downmix part of the decoder is prone to overload, especially when AC3 DRC is set to Off. On the other hand, enabling DRC inserts a crude processor that is impossible to get rid of again. Using the new ‘AC3 Codec’ setting with ALC6′s true-peak limiter to prevent downmix clipping while preserving headroom makes it safe to switch off DRC and AC3 becomes more transparent.
DMix: Mobile Matters
TC’s acclaimed Trickle-down processing is now available for System 6000 MKII. DMix is perfect for converting a 5.1 program to a great sounding mobile platform stereo version in a one-step process; at an impeccable audio quality, and at almost zero latency (0.8 ms).
DMix packs on-the-fly Downmix, Loudness Range conversion, EQ, MS Processing, 5-band Processing and True-peak Limiting into one single, powerful Engine. Consequently, the user may concentrate on a 5.1 mix while DMix takes care of stereo simulcast for mobile or web platforms.
Three new ALC6 and DMix preset banks targeted to ATSC A/85, EBU R128, ITU-R BS.1770-2 and TR-B32 requirements are included with the Live Aid license. DMix presets include acclaimed iX types with image enhancement for listening in headphones or to desktop speakers.
With the new software, System 6000′s integrated Radar Loudness Meter, LM6, also gets two new functions: The meter may now show loudness units in “LKFS” rather than “LUFS”, and a Momentary loudness warning threshold may be set. Real-time loudness warnings are visible in the remote application on a Mac, a PC as well as on the TC Icon hardware unit.
Live Aid – Walk This Way
New software version 5.50 for System 6000 MKII can be downloaded free of charge from TC’s website. With this software update, users get to try the Live Aid license, including ALC6 and DMix, for 200 hours free of charge.
SA Distributor: Prosound