The meeting was convened by chair Peter Mapp.
As there was no formal meeting of the group at the previous convention in Berlin, there were no minutes to approve, other than Peter Mapp had agreed to chair the group.
AES-X218 - "Measurement and calibration of sound systems in rooms."
The chair pointed out that since the last meeting in New York (31-10-2015) there has been no progress. Despite the agreement of those present at the New York meeting to comment on the list of parameters proposed at the meeting and assign themselves to writing groups relating to these parameters, no response whatsoever had been received. On this basis, the parent committee, SC04 had therefore debated whether to close the group but had decided to give it one more go as it was felt to be an important topic.
The Chair went through the list of agreed measurement parameters as below :
After discussion it was decided to temporarily leave writing the section on Frequency Response, as it was understood that the InfoCom draft spectral balance standard was being revised and there was no point in duplicating effort. Additionally, it was agreed that the Temporal Response / Impulse response item would not be considered at the moment as there would likely be duplication with AES-X219 (Method of measurement for frequency and impulse response of sound systems in auditoria) though echoes / generation of focused late reflections may be considered.
* The size of room to which the project relates was discussed and although not restricted it was felt that the objective was for large rooms (as opposed to small rooms).
* Cinema could / would be a specific subset of the work.
* The scope relates to what to measure and how to measure not what the result should be (though some basic commentary may be provided).
* May need to split into basic & advanced tests, bearing in mind the likely test equipment that an average contractor is likely to have.
In order to make and maintain progress, the chair asked for volunteers to head up the writing of the topics listed above and set a deadline of the end of the year for initial drafts of the sections. The chair also commented that unless the attendees at the meeting took an active role, there was little point in them being there!
The table below lists the topics to be covered and writing group members:
|Topic||Task leader / author||Comment|
|Frequency Response||-||Awaiting InfoComm draft (But keep thinking about how to do this)|
|Sound Pressure Level SPL||Steve Martz||A or C weighting? What signal(s) to use?|
|Max SPL||Charlie Hughes||Operating level definition ?|
|Coverage||David Murphy||NB InfoComm document|
|Speech Intelligibility||Peter Mapp||-|
|Distortion||Hughes and Murphy||David Murphy - electronic distortion|
|Background Noise (Room)||Neil Shaw||-|
|System Noise (Acoustic)||Neil Shaw||System noise transmitted into room|
|Reverberation Time||Eddie Brixen||Inc EDT etc (ISO standard) Use of SS for excitation?|
|Gain Structure||Bruce Olson||-|
|Temporal Response||-||In Abeyance|
|Room Acoustic Analysis||Peter Mapp||Will probably include Impulse Response|
|Test Equipment Required & mic locations / types etc||-||Should be covered in individual sections but general discussion/ section probably required|