Originally Posted by caesar1
And this is not a limitation of just the 93 -- isn't this the same for every blu-ray player? In other words, its a blu-ray issue (not an Oppo issue). That is, with any blu-ray player, with secondary audio ON, you always lose Dolby True Hd and/or DTS Master HD when you bitstream -- right?
Secondary Audio mixing can only happen after the primary track is decoded. To then get Bitstream output after the mixing, the result has to be re-encoded on the fly back into a packed, Bitstream format. EVERYBODY does that using either traditional DD or traditional DTS because no player has the horsepower to re-encode back into a lossless Bitstream on the fly.
The 93 uses the highest bandwidth lossy format for that re-encoding -- the 1.536Mbps variant of DTS 5.1
It's a pretty rare person who will be able to tell the difference between that lossy re-encode and the original lossless bitstream.
What's more interesting to me is not what the 93 is doing on that re-encode, but rather what it is doing on the original decode that has to happen prior to the mixing. The 93 is using the full, lossless primary track rather than the "core" or "associated" compatibility, lossy version of the primary audio.
And THAT may make a difference people can hear.
If you use Secondary Audio with LPCM output, you get the full, juicy goodness of the original primary track. If you use Secondary Audio with Bitstream output, the same full, juicy goodness is what gets fed into that DTS re-encode for output, and so the result will be very close indeed to the original lossless Bitstream's bandwidth.