TMPGEnc: What is the advantage of the AC3 plugin?
 

I need help understanding AC3. I have always used mp2 files when I make DVDs. I was thinking of buying the AC3 plugin for TMPGEnc DVD Author. But when I read the specs it says it only encodes 2 channels. I thought AC3 was by definition 5.1 surround sound (5 plus 1 channels). How can something with only 2 channels be called AC3? I do not understand why anyone would want to pay for a plugin that creates a lot of additional work and still ends up with the same stereo I can get with mp2. What is the advantage of the AC3 plugin if it will not encode surround sound?

Re: AC3 question
 

AC3 is up to 5.1 channels.

Whatever the interest nothing (cheap) can encode in 5.1 starting from a 2.0 source. You need a complete audio lab and a sound engineer for performing that.

Also remember that "surround sound" can just as easily refer to Dolby Stereo Surround, aka Pro Logic. It only uses two channels. I assume there's software/hardware that will decode Pro Logic and convert it into 5.1. I also assume it's not cheap ;).

Thank you for the replies. Is there any reason to buy the AC3 plugin for TMPGEnc DVD Author? It would seem from your replies that there is not much it can do.

AC3 generally achieves better compression than MP2, I believe, though I've never done any tests to find out for myself. It would seem to me that there must be a good reason for preferring AC3 since almost every DVD I own uses it for the two-channel audio.

(Off-topic aside: I prefer DTS for multichannel audio, personally. I find it has better dynamic range and a more convincing surround "feel" to it. Completely subjective, of course.)

Exactly the same for me ! I often describe ac3 and mp2 as two boxes arround the gift : the boxes are different but that won't change the quality of the gift that is inside ! But I did not do any comparison test either.

Not subjective at all ! DTS is known for it's better dynamics, particulary on surrond and LFE channel. This is mainly due to less compression. But the counterside is that DTS track uses much more space of course.

Interesting. I remember reading that AC3 is used more in North America, and MP2 more in Europe. Wonder if that's true, and if so, why?

Also interesting. I'm glad it's not just my imagination ;). Personally I'd rather keep the bigger DTS track. I much prefer the sound.

AC3 = Dolby Inc = US pattent (Canada may be ?)
MP2 = Philips = European pattent.
Philips has a BIG weight in European electronics makers world.

I find only ONE drawback to the DTS : it is TOO loud and does not handle Dynamic Range Reduction as AC3 does. That is annoying (for my neighbours) when I am looking LOTR at 3am :-). Balrog rulez :-)

Ah hah :!:

I always do Dynamic Range Control via my amp, which presumably works for any audio source...

But as I know, if you want to ear good DTS sound, you need a distribution of speakers much more strict and exact than Dolby 5.1. Is it true?

I'm not sure. It doesn't really matter how your speakers are distributed as long as the volume from each at your "sweet spot" (for me, my chair ;)) is the same. I have a digital volume meter from Radio Shack and used the test function of my amp to adjust each speaker's volume. It sounds great...

Not, it is not (or your amp is badly desingned) : the DNR of the amp is suppsoed to follow the DNR tag that are in the ac3 stream. That never work for DTS. Read your manual !

(but you can have also a special mode that does not follow the tag as I have also on my SONY. But in mine this switches off also the LFE :-()

I shall. It's a fairly expensive one, so it had better work on DTS too... :angryfire: ;)

One reason for seeing MP2 more in Europe is that an MP2 track won't necessarily work in R1 players. By the standards, MP2 support is mandatory in R2 players but not in R1 ones - I wonder if Philips has anything to do with this :lol:

You misunderstood me : DTS patent owner FORBIDDE to use DNR on their streams. So all "expensive" amp that really paid the license to DTS follow strictly the recommandations. Where cheap ones don't care about :-)

@Boulder
Yes it is. But the MP2 is not mandatory anymore. After 3 years all producers understood that this was a big break to DVD in Europe and turned the "At least a MP2 stream and optionnal other formats" into "At least a Mp2 or ac3 stream and optionnal other formats". Since then MP2 nearly dissapear from the DVD :-)

Seen over all DTS got more dynamic etc. as said above (I only say "S. Private Ryan" ;-) when the "Tiger" Tank gives a shot)

But according to Soundquality ... you will "really" notice that if you got a good speaker setup. I got an active 5.1 Soundsystem incl. selfmade Speakers and a Pioneer DS Decoder incl. DTS support. Sound is overall good mp2/AC3/and shure DTS.

But in comparison with a Soundsystem of a friend of mine (who is a maniac, spending money in such things where others do buy a nice car for those prices) ... I could hear clearly the difference on a TEUFEL Speakers System when comparing AC3 5.1 and DTS by hearing a reference DVD

Ah, they're purists eh? ;) No wonder it sounds better. Perhaps that's part of the reason when I do a compare against AC3: my amp is set to "normal" DRC, whereas it wouldn't apply any to DTS. I'll have to try setting it to "no DRC" and do the compare again.