Logo Channel Activity
Dear Gary:
I’m confused concerning the logo (page 54 volume 17) for movie soundtrack activity, indicating a center surround channel, as I have not seen an AVR or preamplifier/processor with such a designated output. For a 6.1 system, most AVRs and pre/pros instruct the user to use the left-back surround output for a rear single channel. With most of the current codices, this should produce some sound activity. Are you saying that none of the movies reviewed in this issue produce sound activity in the surround-back channel(s).
El Phillips, Goodyear, Arizona
editorgary@widescreenreview.com
Managing Editor Danny Richelieu Comments:
What that means is the audio signal was not encoded with a discrete center surround channel, it is just discrete 5.1.
Your pre/pro can take that 5.1-channel signal and extract a center surround channel (making it 6.1), but that is a matrix extraction, and was not done discretely by the audio mixers prior to encoding the audio signal for the DVD or Blu-ray Disc. If you see a channel activity logo with a colored center surround box, it means the signal was encoded from the discrete center surround channel mix using Dolby® Digital Surround EX™ or discretely dubbed as a channel via DTS® ES™.
With 7.1-channel encodings quickly becoming the norm for bigger-budget Blu-ray Disc releases, we will need to update our channel activity logos.
Unfortunately, the artistic and hardware communities have not come together to create a de facto standard for 7.1-channel mixing layouts, making it not only difficult for us to create a proper channel activity logo, but also making it almost impossible for consumers to listen to the soundtrack as the mixer intended.
Like most people, Widescreen Review has a New Year’s Resolution for 2009, and that’s to take a more authoritative position in getting filmmakers, audio mixers, and hardware manufacturers to discuss this subtle but critical distinction in home theatre layout and design. Because, after all, if nobody knows how the discs are designed to be listened to, nobody will know what compromises they are making in their system or what compromises are acceptable to them.
Our preferred channel/loudspeaker layout was adopted by DTS as their standard optimum layout, which can be viewed on their Web site at http://www.dts.com/Technology/DTS-HD_Master_Audio.aspx.
You can E-mail Widescreen Review @ editorgary@widescreenreview.com