AES Standards News Blog

A revised standard, AES5-2008 AES recommended practice for professional digital audio - Preferred sampling frequencies for applications employing pulse-code modulation has been published 2008-11-12.

A sampling frequency of 48 kHz is recommended for the origination, processing, and interchange of audio programs employing pulse-code modulation. Recognition is also given to the use of a 44,1-kHz sampling frequency related to certain consumer digital audio applications, the use of a 32-kHz sampling frequency for transmission-related applications, and the use of a 96-kHz sampling frequency for applications requiring a higher bandwidth or more relaxed anti-alias filtering.

Further developments in working practices in digital audio have given rise to the use of even higher sampling frequencies and this revision quantifies the preferred choices for these practices. Matters of sampling-frequency precision have been removed from this standard to be handled more appropriately by the associated standard AES11 on Synchronization of digital audio equipment in studio operations.

http://www.aes.org/publications/standards/search.cfm?docID=14

A new document, AES3-Am.6-2008 Amendment 6 to AES3, AES standard for digital audio engineering - Serial transmission format for two-channel linearly represented digital audio data has been published 2008-11-12.

The "minimum" implementation of Channel Status was included in the original AES3 specification to allow implementers to reduce the complexity of transmitting interfaces. Its use has always been discouraged, and in the context of current electronics hardware the complexity saving compared to the Standard implementation is not significant. Moreover, it adds complexity to receivers by requiring them to recognize a special case which does not have a correct CRC in byte 23, and in practice many receivers do not recognize it and flag a CRC error.

This Amendment withdraws the "minimum" implementation of Channel Status. Thus transmitters that use it will no longer conform to AES3, but the practice of insisting on a correct CRC in receivers now will conform.

This Amendment also adds a code point to byte 1, bits 4 to 7, to support the carriage of MIDI data in the user bits as specified in IEC 62537 (digital interface for loudspeakers).

http://www.aes.org/publications/standards/search.cfm?docID=68

The Call for comment on reaffirmation of AES22-1997 (r2003), AES recommended practice for audio preservation and restoration  -  Storage of polyester-based magnetic tape, has been published, 2008-11-03.

The Call for comment on reaffirmation of AES28-1997 (r2003), AES standard for audio preservation and restoration - Method for estimating life expectancy of compact discs (CD-ROM), based on effects of temperature and relative humidity, has been published, 2008-10-27

AES58-2008, AES standard for digital audio - Audio applications of networks - Application of IEC 61883-6 32-bit generic data, has been published 2008-10-03

The primary use of IEEE-1394 isochronous packets, as defined in IEC 61883-6, is for carrying audio and music data. This document defines an efficient means for carrying data in a wider variety of formats, for example professional audio and manufacturer-specific data, in IEC 61883-6 isochronous packets.

http://www.aes.org/publications/standards/search.cfm?docID=65

A call for comment on draft AES54-1-xxxx, AES standard on interconnections - Grounding and EMC practices - Connection of cable shields within connectors attached to portable balanced audio cables, has been published 2008-09-16

A call for comment on draft AES54-2-xxxx, AES standard on interconnections - Grounding and EMC practices - Shields of balanced audio wiring within fixed and portable passive connector panels, jack fields, and passive microphone splitters, has been published 2008-09-16

A call for comment on draft AES54-3-xxxx, AES standard on interconnections - Grounding and EMC practices - Shields of microphone-level outputs of active equipment other than microphones, has been published 2008-09-16

A call for comment on draft AES56-xxxxAES standard on acoustics - Sound source modeling - Loudspeaker polar radiation measurements, has been published 2008-09-11

This standard describes how the measurements of loudspeaker polar radiation data shall be made and documented. This acquired data is suitable for application in room acoustic, electro-acoustic, and sound system predictions, and loudspeaker data sheets.

A new project, AES-X182, AES/Ethernet Simple Open Protocol, has been initiated 2008-09-03 and assigned to the SC-02-02 working group on digital audio interfaces. The project is intended to produce a standard to specify a means for transmission over category 5 data cable of unidirectional digital audio and bidirectional control data. Intended applications are active loudspeakers and amplifiers for live performance and for installations.

http://www.aes.org/standards/b_policies/init-projects/aes-x182-init.cfm