Report of the meeting of the SC-05-05 Working Group on Grounding and EMC Practices of the SC-05 Subcommittee on Interconnections held in New York, NY., on 2005-10-07

The meeting was convened by B. Olson.

The agenda and J. Brown's report of the previous meeting on 2005-05-27 in Barcelona were accepted.

Open projects

AES48-R Review of AES48-2005 Shields of connectors in audio equipment containing active circuitry
No action requested or required

Development projects

AES-X27 Test Methods for Measuring Electromagnetic Interference
This project still needs a volunteer to build the unit designed by Bill Whitlock.

AES-X125 Input filtering for electromagnetic compatibility
Brown has begun a document as a start to providing a Performance test method for common-mode and differential-mode immunity. We would also expect to specify several classes of performance. He reviewed a first draft of this in the WG. A draft is expected to be posted to the WG web-site soon. A robust discussion ensued as can be expected in this group, but I expect that Jim will use it as useful input for the posted draft.

AES-X147A Connection of cable shields within connectors attached to balanced audio cables
Small editorial changes were proposed and will be included in the next draft to be posted.

AES-X147B Shielding of balanced audio wiring within passive connector panels and passive mic splitters
Small editorial changes were proposed and will be included in the next draft to be posted.

AES-X147C Shields of microphone level outputs of active equipment other than microphones
Small editorial changes were proposed and will be included in the next draft to be posted.

AES-X152 Signal levels and impedances of analog audio interfaces
Brown had posted a copy of a piece he wrote for the SYN-AUD-CON newsletter. This will hopefully help get us started looking at the revisions that we may propose for IEC 61938 "Audio, video & audiovisual systems - interconnections & matching values - preferred matching values of analogue signals", and IEC 60268-3, "Sound-system equipment, Part 3: Amplifiers". The first step is to form an interim AES standard that will be in effect until the IEC maintenance cycle able to revise the IEC document. Proposed wording should address specific clauses in the existing IEC standards.

New Projects

A new project was proposed by Jim Brown to revise AES48-2005 to mention in Annex B the case of mix consoles with remote power supplies. A draft should be created along with a PIR. John Schmidt suggested that it might be a separate report instead. The chair recommends that we create the wording and then the WG will decide how to proceed. This should be a new figure and about ten lines of text in the form of the other examples in AES48 Annex B.

New business

There was no new business.

The next meeting will be scheduled in conjunction with the AES 120th Convention in Paris, France, 2006-05.