PCM 7.1 on a 5.1 reciever

[ClaytonMG]

I tried asking this question before and didn't get an answer so I'll try again. If you have a movie that's encoded with PCM 4/3/.01 (7.1) and you're watching it on a reciever that only accepts 2/3/.01 (5.1) PCM signals, do you lose the sound that is in the other 2 channels? Or does it get matrixed back into the side speakers and then if you want you can enable 6.1 EX or 7.1 Pro-LogicIIx to get it semi back to normal?

[ProvenFlipper]

Originally Posted by ClaytonMG

I tried asking this question before and didn't get an answer so I'll try again. If you have a movie that's encoded with PCM 4/3/.01 (7.1) and you're watching it on a reciever that only accepts 2/3/.01 (5.1) PCM signals, do you lose the sound that is in the other 2 channels? Or does it get matrixed back into the side speakers and then if you want you can enable 6.1 EX or 7.1 Pro-LogicIIx to get it semi back to normal?

You'll lose the two rear channels or sound. If your receiver is capable of applying PLIIx to PCM signals then you can do that to the PCM signal.

[ClaytonMG]

So the sound will just be lost? That's crappy! So with titles like The Descent and Crank, the sound for the center back speakers will be gone?

[Ascended_Saiyan]

Originally Posted by ClaytonMG

So the sound will just be lost? That's crappy! So with titles like The Descent and Crank, the sound for the center back speakers will be gone?

Yep, because you don't have a center back speaker hooked to the center back channel on your receiver.

[Deciazulado]

err what kind of connection are we talking about?
hdmi bitstream analog?
for example in analog it's a snap to set up. Just get Y cables and send the 2 left surrounds and the 2 right surrounds to the single left surround and right surround for a 5.1 system.

for a 6.1 one you have more options



and that's if your player can't configure that itself

[GoldenRedux]

I'm thinking you probably have to set your player for 5.1 instead of 7.1, and it will probably matrix the additional rear channels into the surround L/R channels before sending out the signal.

[GTP]

Not sure if there matrixed in...but you only get 5.1 channels at any rate...unless you turn on all channel stereo

[ClaytonMG]

Right now I am using HDMI on a "7.1" reciever. I say "7.1" with the quotes because it doesn't actually accept 7.1 over HDMI. It only accepts 5.1 (there's only a few that actually accept 7.1). And I noticed on The Descent, the audio was 4/3/.01. Which means the 2 extra channels in the back were actually discrete. So what I am wondering is... since those channels are discrete, do I lose them since my reciever only accepts PCM 5.1? Or will it be smart enough to just put them into the side channels?

[Deciazulado]

If the receiver accepts only 5.1, it's not the receiver that might or might not do the "losing" of the channels. It's up to the player, that has to matrix them first 7.1 -> 5.1, so check your player.

[ClaytonMG]

Well I am not even sure if it is losing the channels. But to make my question more specific... Imagine having a 5.1 sound system. Then you get a Blu-Ray with 7.1 sound on it. The player says the audio is 7.1 (since that's what is recorded on the disc), however your reciever is only a 5.1 reciever. Will the extra 2 channels go back into the side channels when using HDMI, or will they just plain be lost? It's kind of like DTS 6.1. Even if you have a 5.1 reciever, you will not lose any of the sound because the extra channel is actually encoded into the side channels. But I am wondering, since this is 7.1 discrete channels and not matrixed into the other 2 channels, will the audio be lost?