Re: [DCP-o-matic] audio loudness

Am 02.08.2014 um 18:04 schrieb Wolfgang Woehl: I just recently came across these ISDCF meeting materials with some interesting aspects covered: http://www.isdcf.com/meeting/Loudness%20Issues%20In%20Cinema%20–%20EU%20-%2… http://www.isdcf.com/meeting/Levels%20in%20the%20Theatre.pdf Adding to my remarks - to be precise, only Level 7 is more or less guaranteed to yield a specific loudness, because that is the fader setting which is (should be) used for the calibration process. While all cinema audio processors use this 1 to 10 scheme, a level 5 on a USL or Datasat processor could/will be different from a level 5 on a Dolby processor. Though I assume that these manufacturers all try to simulate the same gain/fader relation as Dolby does. DCP-o-matic still has a hidden preference option for different level/gain relations of different processors, but I think currently only the Dolby system is used. I think the origin of the Dolby Level numbers is a control voltage steering a VCA block in Dolbys earlier analog processors. I think that they were off at 0 volt and full on at 10 volts. That was a common system for VCA circuits, also in analog music synthesizers of the time. Dolbys later digital systems then tried to simulate the same behaviour, as other manufacturers. Sometimes I come across forum statements from people claiming to play main features mostly at 4-5. Something must be wrong there. - Carsten