AES-X13 and interference-free pro-audio systems

The design of large professional audio systems was never trivial, but the increases in the use of digital, switch-mode and wireless technologies have worsened their interference problems. This situation, increasing EMC regulation, and the poor EMC practice of single-point grounding commonly used in the pro-audio industry, encouraged the Audio Engineering Society (AES) to set up working group SC-05-05 to create a standard on cable shield termination. Two shield termination methods for EMC are discussed in this paper-direct bonding at one end with capacitive bonding at the other, and direct bonding at both ends. The effects on the EMC performance of a large professional audio system of applying single-ended, capacitive, and both-end shield bonding are discussed and test results given. Practicality and costs are also discussed.