Originally Posted by Geoff D
Went back into the PS3 menus again. Under Video Settings I found some more audio options and had a look at BD - Audio Output Format (Optical Digital) which was set to Bitstream (Mix). I changed it to Bitstream (Direct) and now the PS3 is piping out the full-fat 96kHz bitstream over HDMI.
Why the setting for the optical output affects the HDMI bitstreaming above 48kHz I have no idea, because HDMI has its own Linear PCM/Bitstream setting just above the Optical one (which was of course set to bitstream!), but it's working now. Akira too.
Oh, if anyone does an A/B bitstreaming audio comparison of the two Right Stuffs, note that the 48kHz track does not have the +4 dialnorm (see pics below), so if you don't have any sort of dialnorm disabling in your amp then be sure to lower the volume of the 96kHz disc by 4db. Or decode them both as PCM.
(It's worth pointing out that my amp adds +4 to whatever the TrueHD dialnorm reading is, so -4 becomes 0 and 0 becomes +4, but in any case, the 48kHz track is attenuated 4db lower than the 96kHz one, so adjust it accordingly.)
Thanks, got My replacement today and changed My PS3 to Bitstream (Mix) from (Direct) and sure enough it worked. How's that for confusion! I had to do the opposite of You!