Hoping the AVS Forum experts can shed some light on this mystery.
Source: HD broadcast via Comcast cable
Display/Decoder: Sony KDL-46S3000
HTIB: Panasonic SA-BTT490
Issue: Dolby Digital multi-channel audio periodically drops down to 2-channel stereo.
Not sure who's to blame here. The HTIB is the newest component. It decodes Dolby Digital from DVDs and BDs just fine. We are gaming the system a bit here by connecting the cable directly to the TV instead of springing for an HD cable box. The TV picks up all the local HD channels and a few more.
But every minute or so it loses the multi-channel audio and reverts back to stereo. Then a minute later it comes back. And so on. I've seen this behavior in transitions from program to commercial, etc. But not in the middle of the program like this.
I've tried every combination of settings in the Panasonic HTIB to no avail. It displays "Cable/Sat audio not conditional" when I hit Status. The Sony TV has no relevant settings.
Any ideas what might be the problem? Necessary consequence of gaming the system? I haven't tried this with OTA directly as the signal strength out here is poor (Daly City, CA).