I have a standard 6.1 set-up, with a Sony 7.1 receiver, Bose Acoustimas 16 speakers (please no Bose bashing -- not the purpose of this post), DirecTV Genie HD DVR, Panasonic 55" plasma and a Panasonic WiFi Blu-Ray - all wired with HDMIs. In watching normal TV programming (not just movies, but prime time stuff and sports programming), I want to know which Satellite receiver Audio setting I should use: Dolby Digital or PCM? I had always assumed that Dolby Digital would be better and had always set it that way (and understand the reason for that if I am playing Blu-Ray discs) but I've recently experienced significantly lower volume (virtually silent) when the standard TV programming goes to most (not all) commercials or program promo ads during the middle and end of shows (programs sound fine -- it's everything in-between that is off kilter). I assumed that this was some problem with my Sony AV receiver (and it still might be), but when I switched the DirecTV Audio setting from "Dolby Digital" to "PCM", this volume issue for commercials and ads seemed to go away. This, then, got me wondering if the sound quality using the "PCM" setting is as good as the "Dolby Digital" setting (remember that I also want to take full advantage of my 6.1 system). I'd always used the Dolby Digital setting on my DirecTV HD DVR box, but using the PCM instead of the Dolby Digital setting for DirecTV prime time programming output (vice the settings I'd use to play a Blu-Ray disc, for example) seems to sound "fuller". But I'm not sure if I'm losing something (i.e., speaker separation, etc.) by using the PCM versus the Dolby Digital setting. (And, I did read on a couple of those audiophile forums that PCM is actually better quality sound than DD because it's "uncompressed"). As with the Dolby Digital setting, when I use the PCM setting, sound is coming out of all of my speakers (not just just the ones in front, but all surround speakers too) and there is sound coming out for those otherwise silent ads and promos (unlike what happens when I have it set to Dolby Digital). Sort of a nagging side question/concern I've got is that I am still stuck with not knowing what is causing the virtual silence coming via my AVR to my speakers for most ads and promos when I have the DirecTV receiver set to Dolby Digital (I guess that I shouldn't complain, but it's only started in the last couple of months -- I originally thought that the commercial "silence" might have to do with some FCC ruling regarding commercial volume going higher than the programming volume levels -- but I've figured out that's really not the problem here. And the issue does not appear to be DirecTV receiver driven -- the same thing happened on my just replaced DirecTV HD-DVR, as well as on my just-installed Genie HD44 receiver.
