PCM vs. DOLBY DIGITAL DILEMMA

[edmikulski]

Ok. So I just got a Samsung 46" 6300 series LED tv. When I go to the audio menu, to the SPDIF selection, it offers PCM or Dolby Digital, but the Dolby button is "inactive" so I can't select it.Obviously I'm missing something here. Any suggestions??

 

[bandphan]

From what source are you sending optical to the display? What is your setup

 

[edmikulski]

From my HD cable box, I have an HDMI connection to TV. Only other item in the mix is a Samsung 450 soundbar, which is connected via an optical cord from audio out tv. When I go to the tv menu, click on "Sound", I scroll down to SPDIF (not sure what that even stands for). Clicking on it displays 2 options, PCM highlighted, and Dolby Digital below it, but as an "inactive" button. Maybe the PCM is the better of the 2 (?), but I'm unable to compare (due to the inactive nature of the Dolby Digital button).

 

[bandphan]

From my HD cable box, I have an HDMI connection to TV. Only other item in the mix is a Samsung 450 soundbar, which is connected via an optical cord from audio out tv. When I go to the tv menu, click on "Sound", I scroll down to SPDIF (not sure what that even stands for). Clicking on it displays 2 options, PCM highlighted, and Dolby Digital below it, but as an "inactive" button. Maybe the PCM is the better of the 2 (?), but I'm unable to compare (due to the inactive nature of the Dolby Digital button).

You cant strip HD audio from HDMI (with most all displays) and send it back out to a component. You need to run an optical cable to the sound bar from the cable box and the hdmi direct to the tv. If you were feeding OTA singnal to the display or a RF signal from the cable, then you would have the option to send DD out. SPDIF= Sony Phillips digital interconnect format.

 

[edmikulski]

Ahhhh.....good suggestion. I'll give it a try. Just noticed your reference to fried butter. You must be from down here in the South. Only thing I think is more decadent than that, deep fried pork fat. Not the cheap rind stuff you fine at the store, I mean the real deal. Had it in Lafayette LA a few years back. Probably still affecting my cholesterol count.

 

[MDS]

To clarify the difference between the two settings, if you set the output to Dolby Digital it will send the DD untouched to another component for decoding, whereas if you set it to PCM, it will downmix the DD 5.1 to 2 channel PCM.

But as bandphan said, it is not an option because HDMI is connected.

 

[edmikulski]

Hey folks. 1 additional question. Forgot to mention I also have a BluRay player connected via HDMI to the tv (football overload on the brain). The soundbar has a digital 1 & 2. I "assume" that by leaving the current optical cable (as digital 1) and the new cable (HD box direct to soundbar....digital 2), I can still get good sound from playing the dvd player??

 

[bandphan]

Hey folks. 1 additional question. Forgot to mention I also have a BluRay player connected via HDMI to the tv (football overload on the brain). The soundbar has a digital 1 & 2. I "assume" that by leaving the current optical cable (as digital 1) and the new cable (HD box direct to soundbar....digital 2), I can still get good sound from playing the dvd player??

Your fine and that is really the best option you have. Optical and Coaxial digital do not carry the new hd codecs, ie Dolby True HD, but for many including myself the difference between them and Dolby Digital and DTS isnt negligible. And yes Im from the south. Florida now, grew up in NOLA, school at UTK etc etc

 

[edmikulski]

Just a note to let you know I ran an optical from HD receiver to Samsung soundbar #2 digital connection. Echoing problem gone! Thanks again

 

[twosheds]

PCM stands for Pulse Code Modulation. Roughly speaking, it converts the analogue signal to a digital signal that your receiver will handle better.PCM is not a format like .mp3,.cda or .mpg but the name given to the method by which the analogue signal is converted. I had always thought that PCM ment the signal was 2 channel stereo when in fact it is whatever format is passed to the decoder/coder (for want of a better word ?)ie:- DD DD2 DTS 5.1 7.1 blah blah blah you get the picture Hope this helps, Cheers S.

 

[markw]

FWIW, I don't think any TV "passes through" 5.1 their digital outputs. The only 5.1 signal there comes from it's internal ATSC tuner. All other audio is converted to two channel PCM.

If you want 5.1, you need to bypass the TV in the audio chain and connect it directly to the receiver.

FWIW, as for any other sources that output digital audio, you need to set them to "bitstream" to get DD or DTS. PCM will yield two channel.

 

[bandphan]

Both of my Pioneers will pass 5.1 when input via digital, but downmix if via HDMI. Not many displays will do this. IIRC Runco will also. It would be a noble idea to use a display as the switching device as opposed to an AVR