"Uncompressed Audio" Observation/Question

Hi All,

I am new to Blu-Ray, but do have a pretty fair knowledge of modern A/V equipment. I am using a Denon 5803, which is a THX Ultra-2 7.1 amplifier, and it was their "top model" a few years ago when I put everything together. This evening, I hooked up my PS3 in our dedicated movie theater to set things up and to check out and sample a few Blu-Ray titles. Of these titles, I popped in X-men 3, Jay and Silent Bob Strike Back and The Terminator.

Each of these movies had an "uncompressed audio" selection. X-Men3 was first up, and I was very pleased to see that my receiver treated it like a DTS bitstream. The "DTS" indicator light came on, and the receiver automatically decoded the signal in the "Ultra2 Cinema" mode that it was supposed to. This is the exact same thing that happens whenever I feed it a "dolby digital plus" signal from the HD DVD source. All was well.

Now for the confusing part...

Next, I popped in "The Terminator" and noticed that it ALSO had an "uncompressed audio" track on it as well. It had defaulted to "Dolby Digital 5.1", and the receiver (again) automatically flagged it for "Ultra2 Cinema" processing. The indicator light showed that it WAS receiving "multi channel audio", and this indicator is (or course) different than the "DTS" indicator light, and is completely normal when using any traditional 5.1 source.
So, I chose "uncompressed audio" and something REALLY STRANGE happened. The receiver did NOT identify the bitstream as either traditional DD 5.1 OR DTS. In fact, the processing mode that it indicated on the receiver went to "THX HOME CINEMA", which is the normal mode that it will fall back into whenever the audio signal drops down to regular 2.0
Another wierd thing is the fact that (at least in my mind) it "sounded better" and I could distinctly tell that the surrounds were receiving different information than the center and front channels and it appeared that some positional audio effects were taking place. I then put "Jay and Silent Bob Strikes Back" in the player, and when choosing "uncompressed audio", it exhibited the same traits as "The Terminator". I am kind of at a loss as to why the X-men 3 "lossless" mode would be treated by my amplifier as a high quality DTS track, and yet the other 2 movies were not.

So, my question is this... Even though the "uncompressed audio" track on these discs is listed as a 5.1 channel source, my receiver is showing every indication that it is handling it as if it were a 2.0 signal. Has anyone else experienced this, or is this because the data transfer is not compatible with my "3 year old" receiver? If this has been covered before in the past, then I am sorry, but I am new to the "Blu-Ray" experience. Now, before anyone asks, yes I DID set the output to "bitstream" and checked all of the boxes for audio codec compatibility. Any insight that you might be able to provide on this would be greatly appreciated.

In the end, I don't know if it really is going to make that much of a difference in my overall viewing experience, but I would really like to know if the "uncompressed audio" track are supposed to be accepted by my receiver as "non multi channel", even though the menu describes them as 5.1...

Lee

Thanks for the feedback on all of this. I was kind of figuring that since my receiver was processing it as a "2.0" source, then it must mean that it was not accepting it as a multi-channel source. I guess that I will just have to "live with" the regular 5.1 for now, and use the special Fox track when available.
I HAVE been able to listen to the "lossless" audio track on my HD DVD's, since my player has the analog outputs and does the processing "on board". I guess that this is just ANOTHER case of where a manufacturer (Denon) sells something that is supposed to be "upgradeable" and "future proof" though firmware updates, only to find that the "new" state-of-the-art standard has nothing to do with optical or coaxial connections.
I WOULD change my receiver, but I think that would be going through too much trouble. And I don't even think that my ears would perceive much difference. Personally, I can't tell any difference between the "lossless" TrueHD analog output on the HD DVD's versus the "downsampled" version that is processed in my receiver as a DTS bitstream when I select coax as the source rather than the analog inputs...

Lee