Sometimes there is a choice between two six channel audio files. Does anyone have a preference for one over the other?

I don't know if it is the particular movie encoded but the AC3 seems louder...

Thanks,
Johnny

p.s. sorry if this is redundant but could not find any posts specifically dealing with this question.

I think there have been wars fought out on this question!

At the end you'll have to choose what sounds better to your ears!
It depends on the mixing quality at the time of the original's authoring, and consequently changes from movie to movie. Often you also just think DTS or AC3 is better, when it's actually just louder.

Anyway, personally I only take the AC3 tracks, because

• DTS takes a lot more space that is better used for video data
• I don't have a DTS decoder -> no sound
• Even if I had a DTS decoder, guys that I lend a DVD who don't have one can't hear a thing

YMMV

Hey, thanks for the insight. Not interested in started any more wars.

So, do I take it that the AC3 produces louder sound than DTS? I watch them on my laptop & sometimes in noisy environments I need all the volume I can get.

Down the road I can create new ones with DTS if that becomes a viable option given our changing sound set-up.

Again, thanks.

Johnny

DTS has (theoretically, again it depends on the audio mixing guy) a higher dynamic range, the sample size going from your usual 5.1 channel AC3 of 384 or 448 kbit/s up to 1536 kbit/s. OTOH, AC3 has some cunning data compression that DTS lacks and to save bandwith you'll often see DTS tracks with only half the possible bitrate 768 kbit/s which screws of course DTS' theoretical advantage... You see, there are far too many variables to come to a hard conclusion...

Here's a nice explanation of dynamic range:
The difference between the loudest and softest sound in an audio signal. The dynamic range of digital audio is determined by the sample size. Increasing the sample size does not allow louder sounds; it increases the resolution of the signal, thus allowing softer sounds to be separated from the noise floor (and allowing more amplification with less distortion). Dynamic range refers to the difference between the maximum level of distortion-free signal and the minimum limit reproducible by the equipment.

So, I guess you'll often have to increase the volume of a DTS track because it was mixed at a lower level. I could be wrong though...

Great info. Thanks.

One last question. In the new Led Zeppelin DVD that I bought there are 3 sound options: AC3, DTS & PCM. In that video the default was to PCM and therefore if you didn't copy that sound track, no sound would be emitted until you chose the actual audio track (AC3 or DTS) that you recorded.

Do you know of any cases where this is the case with regular movies? If I always go with the AC3, in your experience, do you think I'll run across a similar scenario where possbily the DTS was the default.

Thanks again. And I see what you mean - so much of this is conditioned by the ear of the beholder.

Johnny

I'm not completely sure I understand you correctly. On the Led DVD there's probably a menu where you choose between PCM, DTS and AC3, and its default is PCM, right?

Now, when you do a full-disk copy but only take the AC3 track with you, you think it won't play with sound, right? I take it your example is only theoretical and you haven't yet tried it.
Here's how I think it works:

The menu is programmed to assign every checkbox to an audio stream, e.g

1st box (PCM) -> Audio Track 0
2nd box (DTS) -> Audio Track 1
3rd box (AC3) -> Audio Track 2

Now, if you leave out PCM and DTS, your AC3 stream becomes Audio Track 0. Therefore, either your DVD player recovers gracefully and just takes the only available track or it may even crash/freeze. If that's the case you'll just have to choose the checkbox that corresponds to Audio Track 0 (in our example: 1st box).

To your question, I haven't heard of a movie that had problems with "missing" audio tracks. What can and does happen is that certain audio menu items won't work.

As always, great info. You did understand the scenario correctly and I did indeed attempt the reproduction.

The PCM played on all computers & stand alones and was most likely as you suggested, audio 0. When choosing either of the other audio tracks, neither one of my stand alones were capable of playing it even when that specific audio track was selected at the onset.

Thanks forall your help. You certainly are a wealth of knowledge.

Have a great weekend.

Johnny

Go into your players setup menu for Audio and change output to PCM or similar, you should now beable to listen to the PCM sound




andyw

My pleasure!