Very Odd Audio Problem with ABC OTA signal

[Rail Baron]

I have an HR10-250 HiDef Tivo that is almost two years old. It's hard drive is probably about half full of saved programs and I have a weird problem with my ABC OTA signal. It first happened in May on the Lost season finale. My Tivo is hooked up to my 5.1 home theatre. I was watching it the day after it aired and it was fine until right after the last commercial break. When Lost resumed, I had picture plus part of the background audio but no vocal track. I believe my local ABC signal was 5.1 at the time. In other words, no dialogue but ambient music was present, you know, the faint music that sets the mood of the scene that is in the background of most shows. If I recall the music was coming through the rear speakers only. Being that it was a cliffhanger I was watching without part of my sound, I wanted to scream!

It hasn't done it all summer but last night I was recording Desperate Housewives and it happened again. Last night I turned on the set about halfway into the show. I had all the audio and watched it for a moment. I then paused the live TV and rewound it so I could watch from the start. Suddenly I have picture and ambient music background channel but no dialogue again. Then I switched to the program as it was being recorded and I had the same problem. Arghh!

After it was through recording, I played it back and it had no audio at all, not even at the 20 minute point where I watched it for a moment before pausing and rewinding and it was fine at that point.

It has only happened on ABC OTA which had a 93% (normal) signal strength. Other than the unit responding sluggishly to commands from the remote even after changing batteries, it has acted fine the last few months. It is well ventilated and I know of no other problems it has had. I read a lot about different ailments these units have so I have the same problems others have. I don't really want to give the unit up but can't afford to keep it if it is unreliable as I do time shift a fair amount of stuff on it. I tried a search in this forum but couldn't find this specific problem. Does anyone have any ideas? Thanks in advance.

[markrsmith83]

It's a screw-up at the station.

Many times they switch the output to stereo from 5.1 for commercials. If they don't switch it back, all you get is the front surrounds.

My local WB station used to do this a lot a year or two ago.

[Rail Baron]

Thanks, but that doesn't explain why I had full 5.1 sound about 9:20 pm when I first came to the den and it was not on a commercial at that time. I had turned it on before 9:00 then gone upstairs for a telephone call and that's why I had the whole show int he buffer. I know it was working then. It was only after I paused the live TV and rewound it that I lost the dialog track.


It's a screw-up at the station.

Many times they switch the output to stereo from 5.1 for commercials. If they don't switch it back, all you get is the front surrounds.

My local WB station used to do this a lot a year or two ago.

[WinstonSmith]

My local CBS affiliate does this quite a lot.

For example, last Friday during "Numbers" there was no center channel audio for the first 7mins of the show. Missed the entire startup.

[TyroneShoes]

It might be a problem with the equipment at the station not reliably sensing the flags that tell it which audio track is which and which format (2.0, 5.1) is to be decoded.

DH on the Phoenix station started without center dialog, but switched back to proper decoding about 20 seconds in. (I had to go back and check CC to see what "Mary Alice's" first three lines of voiceover dialog were). It was too subtle and too quick for anyone to realize and then manually fix the problem. And I am listening to analog audio (HDMI into TV, analog audio out to AVR), no DD.

I did not notice the "Numbers" issue, so that must be local, but I did notice a "Numbers" ep a couple years ago that had no dialog for the entire first 25 minutes.

[Bugkillah]

I had a similar problem with my local cbs. From time to time, they will show the sd instead of the hd, but atleast the audio matched the video. Then a few weeks ago they played the 2.0 stereo with the hd instead of the 5.1, and was out of sync by about 5 seconds, very agravating. So obviously, until everything goes hd/5.1, the switching back and forth can potentially cause mix ups.

[WinstonSmith]

What will happen once stations go all digital?

What I mean here -- and I may have difficulty articulating -- are they going to send out a signal in DD5.1 and HD that we can receive on our systems (those that are capable of receiving these signals due to our equipment) and then simultaneously send out a digital signal w/ 2.0 for those who do not have surround sound setups? Or, will it all be encoded on the same signal.

If its the first option, I see tons of problems once the all-digital mandate goes into effect.

[TyroneShoes]

DD equipment that can't handle 5.1 should be able to pick 2.0 out of the same signal, I would think. But audio streams are comparitively small, and won't impact bandwidth issues enough to matter, even if there are multiple audios sent. Broadcasters would probably include a secondary AES audio stream designed for eventual analog playback, just for legacy compatibility.

[Arcady]

The HDTV spec calls for 5.1 decoding capability. You can't have an HDTV receiver that is incapable of receiving 5.1 and at least downsampling to 2 channel stereo.

Of course, it's all moot if the the station messes up the broadcasting.