JeremyR

Just wanting to make sure I understand this HD-Audio thing

Okay,

So I have a Toshiba HD-A2, and an Onkyo TX-SR805 connected across HDMI. I have the Toshiba HD-A2 HDMI audio output set up as Digital Out Auto, which switches between PCM output for DD+, TrueHD, DTS-HD and bistream for Dolby Digital or DTS formats.


So when I put in an HDDVD, my receiver says "multichannel" on the screen, which I'm fairly sure is indicating that it is receiving a PCM signal across HDMI. When I put in a SD DVD, or play my XBOX360, it shows Dolby Digital, DTS, etc.

Regarding the setting when I play HD DVD's, and the A/V receiver shows multichannel on the front display, I do have the ability to switch audio formats which I wasn't expecting as I was under the impression that "PCM" was not encoded in the receiver. However, under further investigation, it appears one of the differences between the Onkyo 605, and the 705's and up are that the 605 is unable to apply DSP processing to a PCM signal across HDMI. However, the 705, 805, etc are able to. So I assume that means that if I were to turn on THX Cinema to a PCM signal for my receiver, that I am not losing the True HD signal. I am just applying the THX parameters to the TrueHD signal. Am I correct in assuming so?

HDnuts100

Re: Just wanting to make sure I understand this HD-Audio thing

Quote:

So I assume that means that if I were to turn on THX Cinema to a PCM signal for my receiver, that I am not losing the True HD signal. I am just applying the THX parameters to the TrueHD signal. Am I correct in assuming so?

Let me ask you, why would you want to apply any DSP processing to a TrueHD track, it's already sounds great, I'd leave it alone.

JeremyR

Re: Just wanting to make sure I understand this HD-Audio thing

You're probably right, except in the cases of when you want to go 7.1 with a 5.1 TrueHD track. I think that is the knock on the 605, as it is unable to matrix a 5.1 signal into 7.1 using THX Neural 7.1 or Prologic IIx. In the 705 and up you can do so. In both of those instances, I don't think you degrade the TrueHD signal, you simply are separating the back channels from 2 to 4. AT least that is my understanding, such as it is.