Originally Posted by bfdtv
That's probably an issue with your Sony TV's Dolby Digital decoder.
By default, the TiVo sends Dolby Digital audio through HDMI to TVs that can accept it. Unfortunately, the Dolby Digital decoder implementation in many TVs isn't well tested.
Set the TiVo to output PCM only. To do that, open Settings -> Audio -> Dolby Digital.
Here is some info on HDMI/HDCP/EDID:http://electronicdesign.com/Articles...602/21602.html
Due to the large variety of AV devices connecting via HDMI, EDID errors are more the rule than the exception. As long as every device, AVR, DVD, Tivo, STB's (especially prone to errors), TV etc correctly identifies itself all is well. If not, you know what happens from your own experience. There are free EDID readers available but AFAIK only for computer monitors. This makes troubleshooting EDID errors for AV devices dicey to say the least.
The HDMI/EDID issue may also explain why users report that DB 5.1 cannot pass from a source via HDMI to a TV and then to an AVR via SPDIF. If the TV EDID reports it has 2 speakers and can only accept 2 ch stereo that is what the source sends and thus no 5.1 is available to pass on.
Current TV sets seem to do better. My 55LH90 does pass 5.1 from a Sony HDD250 DVR and the LG DB390 BR player under these conditions to a Sony 820 AVR which duly reports 5.1 on the display. 390 audio has to be set to pass through for this to work.
The TivoHD on the other hand will only reliably do this when set to DB digital and only for recorded programs. With live reception there often is no sound from the AVR at all with this audio setting although the TV sound is fine and the TV reports DB digital with this setting even for broadcasts that do not contain DB audio (why is that ?).
To get sound from the AVR I have to play a recording first and then switch to live TV or set the TV to tuner and switch back to HDMI where the Tivo is connected. But changing live channels often (but not always) loses the AVR DB sound again.
And with the Tivo audio set to: DB digital to PCM, sound is present but 2 ch stereo only from the AVR and the TV info no longer reports DB.
It seems to me that the TivoHD and the AVR may need an updated EDID.
Why this works with the LG TV ?. Pure speculation. Perhaps because this TV has an SRS audio option reported by the EDID to the source as capable of 5.1