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Audio for mobile TV, iPad and iPod

3 October 2014
Audio for mobile TV, iPad and iPod

This week’s featured white paper from NewBay Connect comes from TC Electronic, and centres on audio for mobile devices.

Audio for mobile TV, iPad and iPod

Among audio lovers, digital has acquired a bad name for its massive use of lossy data reduction, and for its prolific loudness wars that have caused numerous casualties in music, broadcast and film. Most of our music heritage from the past 20 years is in bad shape, and sounds even worse when played on a fine reproduction system.

Unfortunately, the music can be considered lost because neither the session recordings, nor a non-squashed, linear master, are obtainable. Let’s hope the period didn’t have a Beatles, a Kathleen Ferrier, a Dylan, or a Pink Floyd to offer; but that we won’t know without extra hindsight years from now. Another field where hyper-compression is senselessly applied is in broadcast commercials. They are, however, short-lived, and there will be no regrets at not being able to hear them in the future.

More worrying, feature films have also gone into a peak level managed death spiral. Despite well-standardised reproduction systems, thanks to SMPTE, Dolby and THX, playback gain is now being systematically decreased in film mixing as well as in theatres, thereby voiding the immense benefits of calibrated listening. A recent survey of cinema playback level in Denmark places the average at ‘4.75’ on the arbitrary Dolby scale. Reducing the gain by eight to ten dB on the average is a sad sign of the times. At the root of the problem lies peak level measurement.

Rookies as well as skilled operators are misled by an instrument that should only be used to avoid clipping. Even worse, the cheapest way to implement meters in digital audio is based on sample peak detection, so that’s what engineers and editors are still looking at in Pro Tools, Media Composer, Logic, Final Cut, Premiere, etc.

In all areas, audio production must break loose from peak level measurement and from peak level normalisation. Also, studios should cover sample peak meters with gaffer tape. This (white) paper is about getting well sounding audio safely distributed to mobile platforms, and not about producing for lowest common denominator requirements. What makes predictable transmission possible at all is a new broadcast standard where loudness and not peak level takes centre stage. The worldwide cornerstone is ITU-R BS.1770-3, which works across genres and across platforms, regardless of whether linear audio or a wide range of lossy data reduction codecs is employed in parts of the signal-chain.

You can download the full white paper from the NewBay Connect website.

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