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Discussion Starter · #1 ·
There is a HUGE jump from RCA cables to optical cables.



Is there also a huge difference jumping from optical to HDMI audio?




I know I would have to hear it for myself to know for sure, but I want to know the differences in opinions. Thanks a lot



Some people have said dolby digital sounds great, put PCM actually makes you feel like your there....Any truth to this?
 

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Quote:
Originally Posted by jesse40902 /forum/post/0


There is a HUGE jump from RCA cables to optical cables.



Is there also a huge difference jumping from optical to HDMI audio?




I know I would have to hear it for myself to know for sure, but I want to know the differences in opinions. Thanks a lot



Some people have said dolby digital sounds great, put PCM actually makes you feel like your there....Any truth to this?

If you know anyone with a DVD-Audio setup you can listen for yourself. What's being sold today as TrueHD for the new movie discs is the same thing that makes DVD-Audio work.


Compared to DD 5.1, the new high bandwidth formats -- either in their original multi-channel PCM, or "zipped up" into a more compact format such as with TrueHD -- offer a higher sampling rate and no compression. DD 5.1 is a "lossy" compression format that takes lower bandwidth audio to begin with and essentially discards some of it to get it to fit into an even smaller package.


Most people believe they can hear the improvement.


However, these new formats are really pushing the limits of what you can do with audio. And so what you hear will also depend upon how good the rest of your audio setup is.

--Bob
 

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I never compared lossy audio to uncompressed audio with PS3 or PC games. I'm too lazy to test the difference with PS3 games, and nothing will detach me from using multichannel analog with my X-Fi Elite Pro sound card for the PC (as opposed to using a DD Live/DTS Interactive solution). I can say that the Dolby Digital delivered by the Xbox 360 sounds great and certainly doesn't have me longing for uncompressed PCM.


I also can tell you that I notice a difference with a few BD and HD DVD movies. Uncompressed PCM or TrueHD tracks usually have a "fuller" sound to them when compared to their alternate DD or DD+ tracks. Dynamic range is usually better, sounds seem to sometimes come in clearer, and the overall imaging and directionality of effects seem to improve. Movies like Black Hawk Down, Batman Begins and Superman Returns definitely sound better in lossless or uncompressed, than in DD or DD+.


Keep in mind that older movies with dated audio elements, or movies made with subdued audio in general, won't exhibit much of a difference audibly. Also, I couldn't tell you how much of the difference can be attributed to the placebo effect. So just remember that uncompressed or lossless audio delivery isn't going to do wonders for movies with unimpressive audio masters, because it provides the master audio as it is.


This is all just my opinion of course.
 

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Discussion Starter · #7 ·
Compact Disc is PCM, but I dont have a portable CD device to play it



If i play it on my CD player on my laptop or xbox, it wouldn't be PCM quality??



Then again, i have trouble knowing the difference betwee 320kbs Mp3 vs CD quality music...
 

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Quote:
There is a HUGE jump from RCA cables to optical cables.

well chances are the RCA cables are giving you stereo only audio, and while you can 'expand' the sound to multichannel using PLII matrixing on your receiver this is not the same as discrete 5.1 ch audio.


If you have it set up properly, the optical cables carry full 5.1ch DD or DTS audio, and when this is decoded it sounds better than matrixed audio

Quote:
Is there also a huge difference jumping from optical to HDMI audio?

for DD/DTS signals there probably won't be a any difference.


But if you had a HD audio source, these new players will decode the HD audio and produce linear PCM and output that through HDMI. As long as the HD audio source comes from a higher resolution compared to DD/DTS then the LPCM audio will be better than the DD/DTS audio.


Quote:
Some people have said dolby digital sounds great, put PCM actually makes you feel like your there....Any truth to this?

everything depends on the system. if your system is not resolving, you won't notice any difference. if your system is, then you will. Entry level systems may not be resolving enough for you to notice the difference between DD-sourced LPCM and HD-sourced LPCM
 

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Quote:
Originally Posted by jesse40902 /forum/post/0


There is a HUGE jump from RCA cables to optical cables.



Is there also a huge difference jumping from optical to HDMI audio?




I know I would have to hear it for myself to know for sure, but I want to know the differences in opinions. Thanks a lot



Some people have said dolby digital sounds great, put PCM actually makes you feel like your there....Any truth to this?

Do you mean is there a big difference between selecting PCM Stereo as a choice for audio on a DVD compared to selecting a 5.1 soundtrack? I have also wondered the same thing because as of now I only have a 2 channel system and am wondering if the only difference between stereo audio tracks and 5.1 audio tracks is the center channel and surround effects and not "sound quality".
 

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PCM is a means of digitally encoding the audio data. Basically, consider it the "uncompressed" state. CD's have 2 channels of 16-bit/44.1kHz PCM data. A DD 5.1 soundtrack has 6 channels of 20-bit (IIRC)/48kHz PCM data. But it's not stored on disc as uncompressed PCM. It's lossy compressed at a variable compression rate to produce the DD "bitstream". The key point being lossy. Once uncompressed back to PCM to process and convert to analog, something is lost versus the original PCM data. The idea is the compression looses material that our ears wouldn't notice anyway.


I don't know why anyone would bother to put a stereo PCM soundtrack on a DVD. Do not all DVD players these days with analog outs have a means to decode and downmix the DD track to 2ch? If this is not the case, and there is actually a 2ch PCM track which requires no decoding or remixing, then sure, that's what you would pick for playback in a 2ch stereo system. But if you want surround and have a surround system, you would never pick the stereo track.


I think the OP was actually trying to get at the idea of decoded TrueHD and DTS-HD MA into multichannel PCM passed to the receiver over HDMI vs. decoded and then reencoded into DTS or DD which could be passed over SPDIF. If not, then I'm not sure what the OP is trying to determine.
 
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