Anyone else lose their center channel on commercials?

[Pacfanweb]

Or is it just me?

Happens all the time....I'll be watching a game, or CSI, or whatever....getting a Dolby signal, surround is working great, and they break for commercial.

Dolby clicks off and it switches to PL2X. (or Neo or whatever, doesn't matter, most commercials are non-Dolby) And the center channel feed goes away. And I get no audio, meaning I hear some rumbling and background noise from the other speakers, but no dialogue.

Only way I can hear the audio is to switch to Stereo or Mono mode. Then you have to switch back when the regular broadcast comes back on.

Anyone else have this problem? It's not on all commercials, either, but it does happen on a lot of them.

 

[aphex]

That would be a godsend for me, I hate blaring commercials.

 

[skriefal]

Sound like an encoding issue at the station. Like the channels are being mixed out-of-phase in such a way that it confuses the PLIIx decoding. I've encountered something similar, albeit it's been a while -- perhaps a couple years.

 

[Muadib]

I've never had that happen. I would agree that it's at the station, if it only happens on 1 channel. If it occurs on many stations, then I gotta think the problem is with your equipment.

Dolby clicks off and it switches to PL2X. (or Neo or whatever, doesn't matter, most commercials are non-Dolby)

It sounds as though it might matter in your case. Did you try changing your default mode to see if it happens with another mode?

 

[Pacfanweb]

Originally posted by: Muadib
I've never had that happen. I would agree that it's at the station, if it only happens on 1 channel. If it occurs on many stations, then I gotta think the problem is with your equipment.

Dolby clicks off and it switches to PL2X. (or Neo or whatever, doesn't matter, most commercials are non-Dolby)

It sounds as though it might matter in your case. Did you try changing your default mode to see if it happens with another mode?

Only way I don't lose the center output is if it's in Stereo or Mono.

And it happens on lots of channels.

 

[Muadib]

It sounds like it may be your receiver then. You don't mention the make or model, but on my old Rotel, I could set the speakers different for each mode. Is yours the same?

 

[Pacfanweb]

I have a B&K Reference 50 Series II preamp. It has a ridiculous amount of settings. I'll go into the menus and check.

 

[krotchy]

I have had an issue where my center dies switching from Commercial to TV or back. It is really rare, but since I have a DVR I can generally fix things by rewinding 30 seconds and its all good. It has happened twice in a year maybe so its not exactly common.

 

[kalrith]

This happens to me too. Sometimes it'll go to stereo, and other times it will still be on Dolby Digital but will switch to just the L and R speakers. Some shows are broadcast that way as well. Is there something wrong with my receiver, or is this how it's supposed to be?

Edit: I've got a Panasonic XR55. It's set to play true to the source, so it switches between stereo, Dolby Digital, etc. depending on what's sent to it. It's connected via digital coax to an HD DVR (DirecTV HR21).

 

[Muadib]

Originally posted by: kalrith
This happens to me too. Sometimes it'll go to stereo, and other times it will still be on Dolby Digital but will switch to just the L and R speakers. Some shows are broadcast that way as well. Is there something wrong with my receiver, or is this how it's supposed to be?

Edit: I've got a Panasonic XR55. It's set to play true to the source, so it switches between stereo, Dolby Digital, etc. depending on what's sent to it. It's connected via digital coax to an HD DVR (DirecTV HR21).

It hard to say without knowing what shows. Some that are broadcast in Dolby Digital are just 2.0, and not 5.1 . Since you have a HR21, hit the info button, and see if it tells you. They improved the guide, so it might.

If it is going to stereo during commercials, thats normal, unless you have chosen another sound mode, like DTS NEO:6, or Dolby Pro Logic II. I don't recall if you can choose a default mode with the XR55, but it should be in your manual.

 

[pennylane]

It happens to me sometimes. I think the broadcast sends out a Dolby Digital 5.1 signal with blank center/surround/sub channels. If my receiver detects a 2.0 signal, it automatically applies Pro Logic II/Logic 7 or whatever. But i think sometimes it receives a 2.0 signal that's encoded as a 5.1 signal. It thinks it's getting a 5.1 signal even though 4 channels are "blank", so it doesn't bother doing anything about it.

 

[thomsbrain]

You need to set default decoding parameters for various input streams for that input on your receiver. In other words, for the TV input, you tell it how to decode when given mono, stereo, DD, etc. An easy solution is to just set Pro Logic II for everything, so that it will matrix out any missing channels as needed and not be constantly switching decoders.

 

[Pacfanweb]

thomsbrain, that's what I have mine set to do....it will switch to Dolby Digital if it sees that signal, but will use PL2X for everything else unless I manually change it.

What happens is, let's take the Cowboys/Foreskins game last night: It's in HDTV, audio is Dolby Digital. Working great. Commercial comes on....it's not in DD, so the preamp switches to PL2X. But there's no center channel feed. Personally, I think it's either the network or the cable company. If I switch to the same game on an SD channel, it works perfectly in PL2X the whole time....center channel is always on.

But on the HD channels, when they send a non-DD signal, for some reason the center channel goes dead.....and I hear no dialogue...just music, or rumbling, whatever is sent to the L/R channels.

Now if the commercial is a higher-quality one that's HD, it'll work just like the regular broadcast does.

 

[Muadib]

Originally posted by: Pacfanweb
thomsbrain, that's what I have mine set to do....it will switch to Dolby Digital if it sees that signal, but will use PL2X for everything else unless I manually change it.

What happens is, let's take the Cowboys/Foreskins game last night: It's in HDTV, audio is Dolby Digital. Working great. Commercial comes on....it's not in DD, so the preamp switches to PL2X. But there's no center channel feed. Personally, I think it's either the network or the cable company. If I switch to the same game on an SD channel, it works perfectly in PL2X the whole time....center channel is always on.

But on the HD channels, when they send a non-DD signal, for some reason the center channel goes dead.....and I hear no dialogue...just music, or rumbling, whatever is sent to the L/R channels.

Now if the commercial is a higher-quality one that's HD, it'll work just like the regular broadcast does.

Your problem definitely appears to be with your B&K Reference 50 Series II preamp. I say this because you say it happens all of the time, and on many channels. The odds of it being your cable company are almost zero, because you do get sound in your L/R channels. Normal commercials are almost always in stereo. It's your preamp turning it into 5.1.

Did you check to see if there's been a firmware update for your preamp? My Onkyo PR885 had an issue when I first got it, where it would take up to 10 seconds to make the switch from Dolby Digital to whatever mode you set it to switch to. Thankfully, it didn't take Onkyo long to address the issue. Perhaps you can be as lucky.

 

[Pacfanweb]

Okay, I'm watching the football game tonight. NBC.

Sound is great during the game. I paid attention in a long run of at least 4 commercials: On 2 of them, the center channel was on and working just like the game telecast, and on the other 2, there was no center channel feed.

I don't think that's my preamp, since two of the commercials worked. They weren't HD commercials, either.

 

[Pacfanweb]

Here's the answer I got on AVS forum:

NBC doesn't properly flag the audio on their 2 channel content, and ABC has no way to flag it. In either case, the station's DD encoder remains in 5.1 mode all the time, resulting in silence in C/SL/SR/LFE during 2 channel content. CBS and CW provide correct metadata in the audio stream, so the station's encoder can switch to 2 channel mode or upmix to 5.1, depending on the particular equipment in use. Fox upmixes all 2 channel content to 5.1, so this won't affect any network programming from them.

 

[Muadib]

Originally posted by: Pacfanweb
Here's the answer I got on AVS forum:

NBC doesn't properly flag the audio on their 2 channel content, and ABC has no way to flag it. In either case, the station's DD encoder remains in 5.1 mode all the time, resulting in silence in C/SL/SR/LFE during 2 channel content. CBS and CW provide correct metadata in the audio stream, so the station's encoder can switch to 2 channel mode or upmix to 5.1, depending on the particular equipment in use. Fox upmixes all 2 channel content to 5.1, so this won't affect any network programming from them.

If this were true, why am I not affected? I watched the first half of last nights game, and my cs worked just fine.

 

[Pacfanweb]

Maybe your processor simulates surround sound automatically a bit better? I've gotten a couple versions of that answer now.

 

[Muadib]

Ah but you say it happens when watching CSI too, which is a CBS show. How do you explain that?

Since you've been on AVS, did you find the thread for your processor, and see if others complain of the same issue?

 

[Pacfanweb]

You know, I did mention CSI, but I was just throwing a random name out there....I've never watched CSI on my HDTV.

I did watch some of the football game on ESPN last night, and I didn't even turn my main speaker amp on....just the center/surround amp.....never noticed the center drop out on that channel.

I'll start paying closer attention. I do remember noticing it for the first time during American Idol a couple of years ago, when the wife was really into that show.

But I don't watch much network TV....again, I'll start paying closer attention and see if it's only a couple of networks.