PCM AND Bitstream, what is the difference? (1 Viewer)

[Jeff Adams]

This might sound like a stupid question but now that I got a new dvd player and now here a different sound on dvd movies brought me to this question. My old player was a JVC XV-723GD unit. In the setup menu for it, it gave me the option for DD and DTS bitstream or just PCM for DD and DTS. Well I set it to the bitstream and got no audio,then I set it to PCM and got the audio for DTS and DD. Did I set it up properly? I just bought a Denon 1600 and selected Bitstream for both DTS and DD. The sound out of the Denon sounds a lot better now. More open and very detailed, however I have noticed that I have lost some of the low frequency impact that I had with my JVC. What could cause this?

 

[jeff lam]

If you have a receiver with DD and DTS decoders use bitstream. PCM downconverts the 5.1 into 2.0 basically. So if you are using just your TV for sound or just a 2-ch amp then use PCM.

 

[Jeff Adams]

I was just told by someone that the difference is if you are using a coax digital connection then you have to set it to PCM and if you are using the toslink then you have to set it to bitstream. I don't know how accurate that is.

 

[jeff lam]

Nope, both are digital connections and allow your receiver to do the decoding if you have a receiver that decodes DD/DTS signals. PCM is for systems that have only 2 speakers.

 

[Jeff Adams]

That why I put in the comment, "I don't know how accurate that is" I knew he did not know what he was talking about. I still don't understand why I could not get any audio when set up in bitstream on my old dvd player.

 

[Dan Driscoll]

I still don't understand why I could not get any audio when set up in bitstream on my old dvd player.

Did you have a digital coax or toslink cable connected between your JVC and the receiver DVD digital input?

 

[Jeff Adams]

Coax

 

[Dan Driscoll]

Then it should have worked, assuming you had your receiver configured to accept the digital coax input? The only other things that come to mind are a damaged cable, damaged connector of malfunction.

 

[Ken Chan]

I have noticed that I have lost some of the low frequency impact that I had with my JVC

Hmm... when 5.1 is downconverted to 2-channel PCM, the .1 is usually discarded, but I suppose a player could mix it in. Or maybe the player has a "bass enhancement" or other such function which is applied with "PCM"; with "bitstream", it wouldn't make any changes at all.

If the bass is mixed into the main channels, and your main speakers are "large" (are they?), you could get more bass if your sub is anemic or under-calibrated.

In fact, now that you can get true 5.1 -- it does say that somewhere on your receiver, right? -- you should definitely recalibrate your speakers.

//Ken

 

[Jeff Adams]

Ken,
Yes, now that I get true 5.1 it does say that on my receiver. It did not show up like that before. I now hear a world of difference. I went through and reset everything on my receiver,now everything sounds great.