Digital Audio Transmission Impairment and Link Failure: Test Data, and Recommendations for Improved Industry Standards and Reference Designs

Broadcast and cinema applications for digital audio transmission with sample rates (FS) over 48 kHz (e.g. FM digital composite) have experienced signal dropouts and link failures over cables longer than 30 m. Engineers may assume that digital transmission works regardless of source, cable, destination or sample rate. The cables, interface ICs, EMI filters and components for digital audio transmission are designed according to AES-3-4, AES-2id-2012 and ANSI/SMPTE 276M-1995 standards. — The paper presents field observations and test results for 100 m lengths of many types of balanced and unbalanced cables at FS 48-192 kHz, revealing huge variations in cable transmission and received spectra and eye-patterns. — The author includes review and recommendations to update the standards for FS, rise times, bandwidths, eye pattern masks, and circuit designs, to apply to higher transmission rates. The result will be improved and more reliable signal transmission for all sample rates and cable lengths.

Published

2014-10

Content type

Original Research

Keywords

AES-3-4, AES-2id-2012, ANSI/SMPTE 276M-1995, digital audio cable, digital audio transformer, AES/EBU cable, AES-2id, AES3id, 96 kHz sample rate, 192 kHz sample rate

DOI

10.5594/M001548

ISBN

978-1-61482-954-6