While futzing with my Home Theater last night, Panasonic Plasma from last year, Onyx Receiver and Direct TV Sat. & Roof Top Antenna, I found that when viewing OTA signals with the Panny supplying audio to the receiver over the HDMI ARC (audio return channel) there was a lack of Center Channel in much of the programming on the major local affiliates. For example CBS Ch. 2 during 60 minutes center channel worked as expected with all dialogue but the commercial breaks varied. When the center channel goes silent it's like a Dolby Pro logic that isn't being decoded. If I switch the audio out of the Panny TV from auto to PCM then the center speaker always works as expected. When the TV is switched to PCM the ONYX receiver detects a change and the mode display switches from Dolby D to TV Logic. According to the Monitor Manual Help file when in Auto and tuned to an ATSC OTA signal with True HD signal, which I believe is audio jargon for Dolby Digital 5.1, the audio output will be Dolby digital and when it's not an ATSC OTA signal the audio output will be PCM. When I tune to SD stations like the KCBS sister station 2.2 the Receiver detects a change an switches to TV logic and the center speaker works as expected.
As I understand it when in PCM mode there is only enough bandwidth with the optical or HDMI Arc channel for two channels of signal so the 5.1 gets matrixed into what I guess is Dolby Logic or Pro Logic and that's why I think switching the TV to PCM triggers the Receiver to switch to what it calls TV logic, I'm not sure if TV logic is Dolby Pro logic or the more advanced versions of Dolby logic.
All this inconsistency makes me think that somehow in transmission the signal is being flagged as Dolby Digital even when the signal is not. The fact that center channel would come and go during commercial breaks makes me think some of them are dolby digital encoded and some aren't but there is something telling the receiver to treat non dolby digital audio like an older receiver would treat Dolby Pro logic with the logic circuit turned off so things come out as regular stereo. Also when watching the commercial breaks it didn't seem like local drop in spots were the culprit as sometimes the first commercial would have center channel, the second would have center channel and the third would have no center channel. That makes it seem that it isn't just the local or network commercial sections that are at fault but differences in the source material. Most of the episodic programming seemed to perform correctly in dolby digital as did all the ABC programming. The KTLA Friend episode was correct and their local news seemed correct but both CBS and NBC local news has no center channel in dolby digital mode. To add to my confusion when tuned to an HD local affiliate OTA even switching the receiver mode to TV logic with a front panel switch did not activate the center channel.
Can anyone shed some light as to what is getting lost in the overall system. If I just switched the Panny Monitor to PCM it would all work correctly when using the OTA tuner but where's the fun in that? These same channels when viewed from my Direct TV sat receiver have proper center channel. WTF?
John Moore
Barking Trout Productions
Studio City, CA
bigfish@pacbell.net
Barking Trout Productions
Studio City, CA
bigfish@pacbell.net
__._,_.___
Posted by: John Moore <bigfish@pacbell.net>
| Reply via web post | • | Reply to sender | • | Reply to group | • | Start a New Topic | • | Messages in this topic (1) |
.
__,_._,___
No comments:
Post a Comment