losing center channel audio

Discussion in 'TiVo Roamio DVRs' started by Hubb1e, Oct 3, 2014.

  1. Hubb1e

    Hubb1e New Member

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    Update: I switched to optical from hdmI and the issue went away. But now it's back. It happens for me on kids shows on Disney like doc mcstuffins. I can get the center channel back simply by entering into one of the old style menus like settings. Once I hear the TiVo beep noise from the center channel I can resume the show and everything is fine for awhile. This shows me it's in the TiVo and not the Avr. This issue doesn't happen on my TiVo mini with the same show so it's not the recording either. TiVo offered to replace my TiVo but I'm not sure that will fix it and I'll lose all my settings and shows.
     
  2. Dan203

    Dan203 Super Moderator Staff Member TCF Club

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    Bizarre. I was checking out the new menus in the update yesterday and at one point my AVR just started squealing random noise. I backed out a menu and it went away but the menus were silent. I dropped to live TV, where the audio returned, and then went back to the menus and it was working again. So there is something starge going on with the audio there.

    Although, knowing what I know about AC3 I'm still wondering how they could effect just the center channel. Are you sure when this happens the AVR isn't dropping out of DD mode and into PCM mode?
     
  3. Diana Collins

    Diana Collins Well-Known Member TCF Club

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    But if the actual audio data was just L&R then the voices (which would otherwise be on the center channel in 5.1) would be mixed into the L&R audio wouldn't they? To get ONLY the left, right and possibly the surround channels but not hear ANY voice content would mean that the data being decoded was in 5.1 but you are only hearing 2 or 4 of the 5 channels.

    Though I agree, whatever the issue, it is bizarre. We have one Roamio connected to a Panasonic plasma via HDMI and a Yamaha AVR via optical (the AVR is old enough to only have component video). The other Roamio is attached to a Pioneer AVR via HDMI. FWIW, we have never had a problem with missing audio channels. So perhaps it is an interaction between the Roamio and certain AVRs. DirecTV Genies have had similar DD issues with certain AVRs.
     
  4. Dan203

    Dan203 Super Moderator Staff Member TCF Club

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    Yeah it would require some seriously funky mixing for it to drop the center channel completely like that. Any real downmix would include the center channel in the L&R channels. That's why I thought maybe it was switching to PCM and TiVo was doing the mixing wrong. But if it's showing AC3 still on the receiver then I'm back to it being the receiver or TiVo corrupting the headers of the AC3 stream.
     
  5. NorthAlabama

    NorthAlabama tabasco rules

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    to be clear, in my case there isn't a complete loss of the center channel, only certain sub-channels in the center channel mix. my opinion now is that my issue is my avr as dan suggested.

    i don't know if this is new or if i just started noticing, but my avr now indicates a switch to pcm audio if i pause and enter tivo menus. i don't remember that in the past, and was thinking it might have been a change implemented to correct audio issues with some users.
     
  6. JoeKustra

    JoeKustra in the other Alabama TCF Club

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    I remember reading on another thread about the sound effects and the DD license. The TiVo turns off DD when the beeping/noise is used. When a live picture is showing which has DD and you have DD enabled you lose the beep but gain the 5.1 output. If I remember that right. When in SD menus the beep is there but the picture is not, etc., which may be related. Since I don't use a center speaker I would not be able to duplicate the problem even though I have a 7.2 Yamaha AVR. I can see the LFE indicator for broadcast 5.1 and most cable networks with HD channels.
     
  7. Hubb1e

    Hubb1e New Member

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    I did some more research on this issue and found out that onkyo receivers of my generation, 875, have an ac3 bug that does this on some equipment. Switching to the old menus worked because it jumped out of ac3. There's a firmware update that should fix it so I've got to send the unit in or attempt it myself using rs232.
     
  8. Dan203

    Dan203 Super Moderator Staff Member TCF Club

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    Do you even own a PC with an RS232 port? I haven't seen one of those in years.
     
  9. Hubb1e

    Hubb1e New Member

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    I used to work a lot with embedded systems and legacy hardware for work so I have a usb serial port. They are not expensive. What I dont have is windows Xp which is the last supported os. I'm also scared of bricking a $900 receiver.
     
  10. h2oskierc

    h2oskierc I'm a 2-Tuner

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    Really? I just bought a Windows 7 Machine for work that has a serial port. Wonder if it actually works...
     
  11. SeanTivo

    SeanTivo New Member

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    I've had a Roamio for a few months and this just happened to me for the first time.

    I have mine hooked up to a Sony receiver. In the middle of watching a recording of The Americans the Dolby center channel audio disappeared. I checked a recording I'd already watched with no problems and the center channel audio was gone from that too.

    I got the dialogue channel back when I switched to PCM. swapping back to Dolby and it drops the center channel again.

    I'll try rebooting the Tivo and see if that does anything but this will suck if it's not fixed.
     
  12. mikeb33

    mikeb33 Hanger Arounder

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    My Roamio started doing this a few months ago too. I am connected via HDMI to a Yamaha avr. Anybody found a solution? Anybody tried Tivo support?
     
  13. JoeKustra

    JoeKustra in the other Alabama TCF Club

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    I have a Yamaha X-V867. The center channel has an LED indicator when enabled and the dialog lift can be seen with the OSD Audio Information. If the LED is there, but no sound, something is bad. Just guessing: TiVo support is a waste of time.
     
  14. V7Goose

    V7Goose OTA ONLY and Loving It!

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    This is a very old thread, but since it was just revived with a post containing almost no needed information, I add this comment to possibly help others who think they are seeing the same things.

    While many of the original posts from back in 2015 mention multiple stations and indicate a possible problem in the TiVo box, I will say I have never seen those issues as described. HOWEVER, there IS a very similar problem I have seen with ONLY NBC in both Texas and New Mexico. NBC has a problem with their Dolby signal that causes dropouts with the center channel, and I have seen this with S3 and Bolt TiVos on both FiOS and OTA signals AND THE SAME IDENTICAL PROBLEMS WERE THERE WITH SATELLITE SERVICE AND DISH HOPPER DVRs. I stress that last part simply because it proves that this issue with NBC has absolutely nothing to do with TiVo hardware or software. The only solution I have found to the center channel issues with NBC is to use PCM audio instead of Dolby.

    I will describe the symptoms to help others in trying to determine if they are seeing the same thing that cannot be fixed by TiVo:
    First, the problem was in the recorded signal, so rewinding playback would show the same center-channel drops at the same points in the program.

    Different hardware DOES handle the Dolby signal problems differently. It is especially bad on my Sony AVR, with the audio drops on the center channel making it impossible to watch many programs. On my Yamaha AVR, you can clearly hear the signal switching in and out of normal Dolby sound, with the dialog moving from center to the L/R channels, but the total volume does not particularly drop like it does on the Sony, so the same programs are still watchable (but irritating). BOTH amps have displays that show not only the presence of a "Dolby" signal, but also which specific channels are being received, and this problem does NOT change those displays, so the receivers still think they are getting a complete Dolby signal, even when the modulation drops out of the center channel.

    In Dallas on FiOS, the problem seemed to affect all programs similarly (using the Yamaha AVR and optical audio connection), with the NBC audio significantly lower than any other station due to the loss of audio on the center channels. Strangely, I do not recall significant issues on the same station with the Sony AVR and HDMI audio, but I guess it is possible I always had that box set up for PCM audio out. Here in New Mexico, the problem is MUCH worse with local broadcasting (non-network originated), such as the news programs. As soon as the morning news is over and the Today show starts, the problem mostly goes away (mostly, but not completely). The engineer at the Albuquerque NBC affiliate insists that they do not transmit any Dolby signal at all, despite the fact that any Dolby-capable AVR shows that it is receiving a Dolby signal.

    Finally, I will note that both of my AVRs were purchased way back around the time that the S3 TiVos were relatively new (so about 10 years old now). Perhaps newer hardware handles this problem better? Certainly seems possible, considering how different the symptoms are between my Sony and Yamaha receivers; I have no way of knowing.

    Bottom line for me is that you should first see if the audio signal issues are recorded in the program and repeat identically when you rewind the program. If they are, then there is probably nothing you can do about it except use PCM audio out.
     
    Last edited: Jul 20, 2017
    tim1724 likes this.

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