Yesterday I switched "from" having both my sources feed into my Yamaha RX-V661 7.1ch receiver via HDMI's and then out to my PJ via a single HDMI..."to" having both sources' video outputs straight to PJ via HDMI and both sources' audio outputs from sources to my receiver via Digital Optical cables.

This gave me the same DB output @ -12db less on my receiver than before???
I've read 'countless' times that digital optical cables can only carry somewhat lossless 5.1ch and HDMI can carry true lossless 7.1ch....so why does it sound a little better and definitely much louder now using the digital optical for the audio instead of having the HDMI handle both video and audio??

Yesterday I switched "from" having both my sources feed into my Yamaha RX-V661 7.1ch receiver via HDMI's and then out to my PJ via a single HDMI..."to" having both sources' video outputs straight to PJ via HDMI and both sources' audio outputs from sources to my receiver via Digital Optical cables.

This gave me the same DB output @ -12db less on my receiver than before???
I've read 'countless' times that digital optical cables can only carry somewhat lossless 5.1ch and HDMI can carry true lossless 7.1ch....so why does it sound a little better and definitely much louder now using the digital optical for the audio instead of having the HDMI handle both video and audio??

The lossless audio formats have much more dynamic range than the compressed formats. This could result in the lossless formats being "quieter" depending on the source material. As far as sounding better, that's in the ear of the beholder. ;)

....but in theory, compressed audio should not sound better.

O.K.
1. Optical audio is compressed then?
2. For the first time since I bought the receiver though the display shows the "DD" with the second backwards -then- D+PLIIxMusic...whereas before it never showed anything but PLIIxMusic, even when playing Ghost Rider on Blu-Ray........so I think I've unlocked something??

I'll just say this: It doesn't matter where your volume control is to get the same volume. I don't know how people use that as a valid comparison. As long as your receiver/amp can get to the volume you want, it doesn't matter.

I agree, but as I said above I 'think' I unlocked some sound option which led to the new display and louder volume. I don't think it is just louder, it sounds a little better too.

1. Is Optical audio is compressed then?
2. For the first time since I bought the receiver though the display shows the "DD" with the second backwards -then- D+PLIIxMusic...whereas before it never showed anything but PLIIxMusic,........so I think I've unlocked something??

What is the difference between "PLIIxMusic" and "DD D+PLIIxMusic" ??

Maybe over HDMI it was getting PCM and over optical it's getting bitstream.

What are your sources? DVD? Blu-Ray? Cable box? It might have had a different default setting for the HDMI than the optical, although I'm just guessing.


What is the difference between "PLIIxMusic" and "DD D+PLIIxMusic" ??

From my understanding, PLIIx Music (which is ProLogic IIx - Music, along with the other PLIIx forms) is a processing mode. DD is Dolby Digital, which is a sound format/codec. You can apply PLIIx to DD, or stereo, or whatever. So before it was applying PLIIx to whatever you were getting before, and now it's applying it to the DD.

The DD with the second backwards is Dolby Lab's logo, typically signaling that one of their formats is in use. My Onkyo receiver does that, too, and will kick on a DTS logo if one of their formats is in use.

Maybe over HDMI it was getting PCM and over optical it's getting bitstream.

What are your sources? DVD? Blu-Ray? Cable box? It might have had a different default setting for the HDMI than the optical, although I'm just guessing.




1. If that is true then when I play a disc that has 7.1 lossless or TrueHD audio I should switch back to get LPCM, right?? In order to get lossless 7.1??

2. local HD-DVR
Oppo 980HD
Mitsubishi HC1500 720P PJ
Yamaha RX-V661 receiver(that does pass lossless)

What you have done is change the place where decoding is taking place. When your receiver only shows PLIIx, it means the player is doing the decoding, sending high-resolution decoded data to the receiver, and the receiver is doing matrixing of the back channels. When you see DD+PLIIx, it means the player is sending a compressed signal to the receiver, and the receiver is doing both decoding and matrixing.

If the source material is compressed, then you can pick the option you feel sounds better (although some more modern codecs may need information that only the player has, not the receiver). If the source material is uncompressed, though, the player would have to compress it to send it to the receiver, which would be a loss in quality.

Optical can carry two kinds of signal: compressed multi-channel signals, or uncompressed stereo signals. HDMI can carry the same, but can also carry uncompressed multichannel signals.

So should I go back to my old set-up configuration??
Old:
HDMI from (2) sources to receiver...then single HDMI from receiver to PJ
New:
HDMI from (2) sources to PJ...then Dig. Optical Audio from (2) sources to receiver(and I have to manually switch the HDMI's into the PJ as it only accepts one)


On a side note, do I want my loal cable companies HD-DVR box and my Oppo 980HD doing the decoding....-or-....should I let my Yamaha receiver do it? --IYO

And Thank You littlesaint-tulpa-jwatte!

1. If that is true then when I play a disc that has 7.1 lossless or TrueHD audio I should switch back to get LPCM, right?? In order to get lossless 7.1??

2. local HD-DVR
Oppo 980HD
Mitsubishi HC1500 720P PJ
Yamaha RX-V661 receiver(that does pass lossless)

Uh, I don't think anything in your indicated setup is using any type of lossless 7.1. The DVDs certainly aren't, and I don't know of any DVRs that do. although I could be wrong there.

If you have a PS3 or other Blu-ray player or an HD-DVD player, then you would use LPCM for lossless audio. Otherwise, I'd see if you can't output bitstream on the DVD player (either optical or HDMI, if that's an option. I don't know your DVD player's options.) No idea what the DVR would use other than maybe a "Dolby Digital" setting in its audio options. I always find the receiver usually does a bit better job decoding than the DVD player, at least with the ones I've used. Never tried an Oppo one. Basically, trust your ears.

I'm sitting here switching the HDMI's and the Optical Audios and getting turned all around. So confused. When I bought this I set it up for a Bluray player I had but do not have anymore.
So you are right that I don't have any sources currently pushing 7.1
-The DVD player can down mix to 7.1ch but no standard def dvd's have 7.1
-The HD-DVR can output "Stereo" or "Advanced" which then has extra set-ups of compression choices(using "none") and stere output-Stereo or Matrix(using matrix)....t.v. offers no more than DD.
.....still don't know what to use here??

So with that said to get the purest audio....do I do the "Old" set-up config. -or- the "New" set-up config. from the post above yours??

I think I should just stick with the "Old" set-up of only HDMI's....but I obviously am not sure.

My other last question is on my HD-DVR box...when I choose the Stereo mode it is louder than when I choose the "Advanced" mode with "No" compression and "Matrix".
Is this to what was being said earlier that compressed audio, i.e. when I choose "Stereo" mode on the box, is louder?

Maybe over HDMI it was getting PCM and over optical it's getting bitstream.
It might have had a different default setting for the HDMI than the optical, although I'm just guessing.



You are correct about that. After setting it back up like I had it before with audio and video passing through the receiver via HDMI the "PCM" came back onto the receivers' display. It would not appear when the video was going direct to PJ and audio only was going to the receiver via Optical.

I believe with the components you are connecting it doesn't matter which connection you use, HDMI or Optical. Since your sources can only max out at a DTS soundtrack either connection will pass the DD or DTS signal to the reciever. You have to use the HDMI for audio if you were to hook up a BLu-Ray or HD-DVD player and wanted to get the uncompressed audio formats (PCM, TRUEHD, DD+). Also you shouldn't be listening for "louder" but more like "clearer". Your volume levels are probably differing because if the signal is bitstream the recievers speaker levels are used and if it is PCM usually the speaker levels from the source are used (at least in my limited experience). So if the DVD players speaker levels are lower than the recievers you will end up with a diffrence in volume even though you havent touched the volume knob on the reciever.

I caveat this with the fact that this is from my limited experience with my own setup and from a lot of reading to get my home theater working to what I believe is its potential.

When I bought this I set it up for a Bluray player I had but do not have anymore.

You used to have a Blu-Ray player and not anymore? Then I agree with others here. There will be no difference in audio between HDMI and digital optical. Both will pass all the audio your current sources are capable of. The only time you will want/need to go HDMI is when you get a Blu-Ray player that will decode TrueHD, DTS-HD, or even SACD and output it as multichannel PCM via HDMI to your v661.

To throw another option for you, if your Blu-Ray player can also decode TrueHD, DTS-HD and has multichannel analog outs, then you can use that instead of HDMI. :)