I think you mean PCM and not DCM. 

If your reciever doesn't have HDMI input capability, but it has the 5.1 analog inputs then I, personally, would recommend using the analog 5.1 inputs instead of coax/optical input.  You'll get the full capability of the audio from your player.  Anything sent over coax/optical from the player will get down-converted to DTS.

If you are only getting stereo over coax/toslink make sure your player is set to output audio via PCM and not bitstream.

My Yammy receiver doesn't have HDMI inputs so my HD DVD is connected via analog 5.1 so that the player does the decoding and sends it straight through the receiver.  This way I get TrueHD and DD+ as it should be heard.

My PS3 is hooked up via Optical to the receiver and the PS3 coverts the audio to DTS.  If the PS3 is accidentally set to output Bitstream then I only get left/right stereo.  When set to PCM I get the 5.1.

David,

I'm sorry, my mistake.  I gave some wrong info.

When listening to PCM over coax/optical you will only get two channels.  S/PDIF can't carry 5.1 PCM.  If you hook up the player to the receiver via analog (multi-channel) then you'll get the 5.1 PCM.  The uncompressed sound may surprise you at how well it sounds depending on your system.

DTS-HD MA contains the DTS core and will be seen by the receiver as DTS over S/PDIF.

Dolby Digital Plus will be seen as Dolby Digital on the receiver over S/PDIF.  Dolby TrueHD, I believe, is also seen as Dolby Digital by the receiver over S/PDIF, but at a higher bitrate.

Dolby Digital, of course, will be seen as Dolby Digital on the receiver over S/PDIF.

Bottom line, if you want to listen to uncompressed PCM, then you need to use either HDMI to the receiver or the 5.1 analogs.  Is it the best option?  Depends on your equipment and your listening environment.  If you have spare RCA cables laying about give it a shot.

You're best bet is to go with HDMI or analog outs (the 6 plug option).  I don't know enough to say which is better of those two, but they'll both play DD+, TrueHD and PCM and any other advanced audio codecs your player can convert (or send them straight to the receiver if your receiver can decode the newer audio track and your player will send them).

The next step down is coax or optical.  Again, I don't know which is better, but neither will give you any of the advanced audio codecs.  They'll be down converted to either DD or DTS then sent to your receiver.

This is from an HD DVD owner, but I believe it hold true on the Blu-ray side as well.

unless you have HDMI in on your receiver then you have no choice but to use the analog 5.1 RCA ouputs and let the blu ray player do the job of uncompressing the audio...if you want to get the best quality sound from your discs that have a lossless (DD TruHD or DTS HD) or umcompressed PCM. Coaxial and optical are effectively identical and the SPIDF fomat they use cannot handle the bandwidth requirements for lossless audio, or even higher quality DD+ tracks. Also your receiver cannot decode those tracks on its own. The good news is that the Blu Ray player is more than up to the task. I think you will be very satisfied with your sound if you stick with the 5.1 analog RCA.

If you use a coax or optical connector your blu ray player will down-compress the audio tracks into something your receiver can decode, either 5.1 DD, DTS or possibly 2 channel PCM. If, however you use the 5.1 analog connectors your blu ray player uncompresses (as opposed to downcompresses) the audio to analog audio signals which your receiver then passes direcly to the speakers with only amplification. Using the analog connectors bypasses your receiver's digital processors entirely. You have 6 wires going from the player to the receiver. 1 front left, 1 front right, 1 rear left, 1 rear right, 1 centre, and 1 for the sub-woofer. It does not get more separated.  When dealing the the advanced audio options that the blu ray player offers such as lossless (DD Tru HD or DTS MA HD) or uncompressed PCM this is the best choice for your current receiver.

As a comparison, my Yamaha has HDMI, but while it can use uncompressed multi-channel PCM, it cannot decode the lossless codecs on its own. So I have my HD DVD decode those codecs to uncompressed multi-channel PCM. The end result is basically the same as using 5.1 analog cables, but I only need the single HDMI cable. The sound is noticeably better than when it is connected using coaxial or optical for those discs with the more advanced and lossless codecs.

So in short:
HDMI good.
5.1 analog RCA good.
Optical or coaxial less good.

I hope this helps.

Quoting davidperez:

Quote:
Ok, now I understand what the difference is. So now my question is, which one is better? If I go to someones house that has a $100,000 theater set up. How do they connect their blu-ray to their receiver/amplifier. I know a 100k theater doesnt normally use a recevier, but instead they probably use seperate amps for each channel, but for arguments sake, lets say they have a receiver. Which connection am I most likely to see? Optical/Coaxial for audio or the seperate rcas? I thought the coaxial was digital and digital was the "Only" way to go?

With someone who has a $100,000 system you're going to see actual British actors acting out the movie on the guys stage. 

What you'll probably see is a combination of HDMI from the player to a BALUN run of Cat5e/Cat6.  Since you are worried about the basics here it is best not to figure out what a $100,000 system looks like.

Coax is digital, as is TOSLINK and HDMI.  Bear in mind that there are limitations for each.  Think of comparing a one-lane highway and a two-lane highway.  Both are highways, but obviously the two-lane can carry more traffic than a one-lane.  Such is the same for S/PDIF and HDMI.  Both are digital but S/PDIF is the one-lane highway; HDMI is the two-lane highway.

Quoting davidperez:

Quote:
It helps trememdously, thank you. When you say the sound is noticably better? What does that mean? Does it mean? Does it mean that I wont have to play my receiver at volume level 50 to get loud enough sound to be able to hear the voices? Or does it mean that, the sound for example, the sub woofer wont have any of the music that I seam to get now when I reaise the cut off frequency? Because I think that is what is making my subs rumble to the point of distortion when there is an explosion or a loud rumble noise. So long story short, what is "noticebly better" sound. I really appreciate you taking the time to explain this to me, especially on Christmas Eve.

Better doesn't mean louder.  It just means you will hear the full range of sound.  You might even notice things you didn't hear before when just listening to audio over COAX.

Long story short.  You have two multi-channel inputs on your receiver.  Use one of those inputs for your Blu-ray player and ditch the COAX.  You will hear the sound as it's meant to be heard.

Yes, it's more cables creating a rats nest, but the audio listening experience is well worth it.

In the future, if you upgrade your receiver, make sure the receiver has HDMI and that it is HDMI v1.3a for TrueHD and DTS-MA HD decoding.  But for now, use the RCAs.  This way you get the Hi-Def sound along with your Hi-Def picture.

Two other thing, should I still leave the Coax connected to my receiver in case, I buy a blu-ray disk that doesnt offer the uncompressed audio? Or do all blu-ray disks have this? Cant I just leave it connected and choose in the disk menu which audio I want to send to the recevier? The other thing, is will I need to adjust the settings on my subs to a different setting after i connect the player using the RCA?