I have read controversial discussion about these two mediums and wish to know what you all think.
"Personal taste" is the most often used line where comparison of DD vs DTS is discussed.
After setup of my 950 & 755 with a Pioneer DV45A, my personal opinion is that DTS wins out without any doubt !
Discs that enable either format and demonstrate this clearly to me are:
Gladiator, Minority report ( stunning!)
& Shrek.
The Dts tracks on these DVDs are way more dynamic, open and airy. Dolby Digital sounds veiled by comparison.
I wonder now if this is somehow equipment related? Does anyone have any experience where it was hard to differentiate?

You've probably read this already, but Boblinds and myself did some comparisons of DD and DTS.

http://ubb.outlawaudio.com/ubb/Forum6/HTML/000199.html

While I found the DTS to be better sounding overall, I also noted some differences in the mixes that could not have been the result of the DTS and DD encoding per se. I know that in the past, DTS made their "master" from the 6 track magnetic film safety master of the film soundtrack. Beyond just sounding more "euphonic" because of a generation of magnetic film recording, they had their own proprietary equalization which boosted the bass beyond what was flat. Dolby digital is always mastered directly from the mixing console during the dubbing process.

While I found the DTS to sound better to me, the Dolby Digital version was more what the film sounded like when it was being mixed on the dubbing stage. The DTS by compaison was more "pumped up" sounding.

Keep in mind that DTS uses a data rate of one half of their usual 1.5 megabits per second for DVDs, so the data rate gap between it and Dolby Digital is not quite as wide as it would be otherwise, such as on DTS CDs.

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The Soundhound Theater

noone here knows this better then soundhound. Read his words and let them sink in

Personally, I have done comparisons with the 20 or so dvd's I have that have DTS. Some are better with DTS, others sound washed out when DTS is chosen. I have a list for each movie so I get the best sound for each one.

Example, Blade 2. DTS version sounds weak all around...but in DD, the LFE seems to be very exaggerated. But in the end, Id rather have the potent LFE, turn the sub down...then have a weak sound.

Another example...Reigh Of Fire...DTS version kills the DD version. I could use 20 examples but you get my point. Compare and keep a short list of what you preferred

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Play it LoUd!!

Stuart Robinson of the SMR Forums (http://forums.smr-forums.com:8080/) did an analysis of three encodings of the same recording: Dolby Digital, DTS, and MLP. He found that DTS was the least faithful encoding method, in terms of differences from the original.

This doesn't mean that DTS won't sound better to you. That's a matter of personal preference. But it does mean that if you're looking for the most accurate encoding method to represent the artists' intents, then DTS ain't it.

BTW, it bears mentioning that DTS has for a long time boosted bass levels. It's a known psychoaccoustic phenomenon that "louder" is often perceived as "better" to an uninformed listener, hence the neccessity to do a double-blind level-matched test in order to fairly compare DTS to DD or MLP.

Jeff

it's a phenomenon to me how the 'experts' write an article and many people latch onto what is said.

from the player, to the chosen routing scheme and processing method, preamplification, amplification and playback through 6 or 7 or 8 loudspeakers, an original mix of any format can emerge as nothing like itself.

i'm just glad there IS a competing format to DD.

Just to clarify what Soundhound and I were hearing a couple weeks ago: It was a MUCH more striking difference (with more subtlety) than a louder level. There were many other DTS differences that were preferable to DD ... and not all of those could be attributed to EQ variations.

I'd love to see the article on SMR. Do you have a title for the thread or a direct link? I didn't have any luck trying to search it out over there.

Finally, a DTS anomaly. I rented Moulin Rouge last week (hated it, by the way) and the DTS track was out of sync. I thought it was something wrong with my system until I switched to the Dolby track and all was well. I did find a couple references on the web that others observed the same thing.

Could be an anomaly in my equipment, of course, that some others share as well. But it was pretty weird.

bossobass,

With your nom de plume, I'm not surprised that you prefer DTS. DTS is famous for having "accidentally" boosted the bass in its soundtracks, resulting in the psychoacoustic phenomenon that I mentioned.

Yes, you're right that it's impossible to perfectly reproduce the original material. But does that mean that we should forget about fidelity alltogether? Perhaps you should forget about compact discs, DVD-A, and SACD: after all, it's impossible to get perfect sound, so you might as well stick with cassette tapes, right? Or for that matter, why not stick to wax cylinders?

Obviously, there's a point to trying to get as accurate a reproduction as possible. Every little bit helps, and the end sound is only going to be as good as the weakest link in the chain. Why degrade that chain further?

And as to your glee that DTS is a competitor to Dolby, I'm happy you're happy, but if you looked into DTS's misleading marketing practices a little bit more, I'm not sure you'd be has pleased.

I've personally met a lot of the folks at DTS, and they're a swell bunch of guys and gals and all, but the way they sell their product is unpleasant to me.

Jeff

You'd be surprised. It bears mentioning that the DD and DTS versions of the same film often come from different masters, hence it's hard to tell which format is really better. The reason Stuart was able to do so in this case was he had a known instance where he knew it was the same master, and he had the MLP (lossless)-encoded version to work with as a base of comparison.



Sorry, I don't. You should register and then post your query in Forum 1. Nigel or Stuart may be able to post a link for you. Tell 'em Jeff sent ya.




Probably just an error in the manufacturing process, or possibly the encoding process. I don't think it's any indication of DTS's quality, or the lack thereof.

Jeff

P.S. You probably should check out this article: http://www.smr-home-theatre.org/Schneider/Schneider.html

I've posted this before, but in case anybody missed it, here it is again:

What Dolby Digital Doesn't Want You To Hear!

This is a snippet from the master of a piece of music on the LEFT channel, and the identical snippet from the resulting DVD after Dolby Digital encoding/decoding with the original master subtracted, on the RIGHT channel. The result is what was REMOVED by the Dolby Digital process. You can hear that as the music gets more complex, the amount of "removed" material increases.

The DTS process works basically the same way, the difference being in the degree of material removed.

Give me uncompressed, please

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The Soundhound Theater

Quote: You'd be surprised. It bears mentioning that the DD and DTS versions of the same film often come from different masters, hence it's hard to tell which format is really better.

Like I said above, this is always the case. Dolby Digital sends a tech to the dubbing stage after the film is mixed, and the output of the mixing console is fed directly to the DD encoder, where it is recorded on magneto optical disc. The DTS master is always made after the fact, at their facilities. At least in the past, this was from the 6 track magnetic master, but now the option exists for their master to be made from a hard disc copy of the master from the dubbing stage, or from DA-88 tape.

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The Soundhound Theater

Are you talking about a film soundtrack here or an audio disc? "MLP" says to me that the original has already been altered in some way or another. Also, I've never heard of MLP as a compression format for a film.

Soundhound's comparison is really nice because he has the "original" audio files to compare to the DD and DTS versions of the film.

One more thing, as mentioned in the article that D'Arbignal linked to; hearing and percieving are two different things. I would add to that list the word listening. I do, however, like that the article mentions that musical enjoyment is really not measureable.

Jason,

Exactly right. That's why I said that DTS is less accurate but that's not the same thing as sounding worse. The encoding method that sounds the best is just that: whatever you like. If you like listening to DD, great. If you like DTS, that's great too. And if you like two tin cans and a string, that's also great.

My point was to address the fallacy that people have that think that because DTS is less compressed that it's somehow more accurate. It's been our conclusion that DTS simply has a less efficient coder, hence a greater number of bits are required simply to store the same data.

Jeff

I agree that uncompressed is preferable, but don't mistake DTS's high data rate for more data. It's quite likely from our findings that DTS simply uses a less efficient coder than Dolby's.

For instance, let's say that I had 1 GB of data, and I run it through two compression algorithms: A and B.

Algorithm A compresses very efficiently, and the resulting data is .4 GB.

Algorithm B is less efficient, though no more accurate, and compresses the same data down to .7 GB.

Does this make B a "better" algorithm than A? If you work for DTS's marketing department, it does.

Jeff

I forgot to mention an interesting comparison I attended several years ago. I was working on the film "True Lies" and the producers were trying to determine what audio formats to release the film in. A "shootout" was arranged where a reel of the movie "Terminator II" was submitted to Dolby for Dolby Digital encoding, and to DTS for DTS encoding. The reel of the film used was the one with the "nuclear nightmare" sequence.

The representatives from Dolby and DTS brought their endoded versions of the soundtrack to the dubbing stage, where the original 6 track magnetic master was also loaded on a mag reproducer. The reel of the movie was run with picture, and surprisingly nobody was able to tell the difference between either of the formats in relation to each other, or to the original 6 track master. The only thing I noted was that the DTS playback was "hissier" in the absence of signal. This was a really shocking demo, but considering we were listening to a reel of film that consisted mainly of either very soft foley effects or very loud "nuclear bomb" sound effects (and a "synthesized" music soundtrack), the results are not surprising.

I'm sure in this demo that DTS took great pains to ensure "accurate" encoding, otherwise the film's original mixing engineers (who were present) would spot the tinkering with the soundtrack immediately. All present at the demonstration were well aware of what the "artifacts" of lossy encoding sound like.


[This message has been edited by soundhound (edited February 26, 2003).]

Soundhound,

Oh, I'm not saying that DTS sounds worse than Dolby Digital. I'm only contesting the "DTS wins out without any doubt" claim.

My impression is that while DTS is slightly less accurate than Dolby, the quality is more or less the same. Some say DTS is better, others say Dolby is better. For me, I'll just buy whichever one is less expensive (usually, but not always, the Dolby Digital).

Jeff

[QUOTE]Originally posted by D'Arbignal:
bossobass,

With your nom de plume, I'm not surprised that you prefer DTS. DTS is famous for having "accidentally" boosted the bass in its soundtracks, resulting in the psychoacoustic phenomenon that I mentioned.
[/QUOTE
__________________________________________

DTS's LFE channel was/is different? they actually used/use a 5.0 system in cinema soundtracks (don't know if they still do). the LFE channel from the mixing sessions gets low passed @ 80hz and added to the satellites. at playback, the satellites are high passed @ 80hz and the remainder becomes the LFE channel. DTS's original encoder was for full range channels which would have required 20% more space on the disc (as a full range .1 channel).

Dolby's LFE channel is bandwidth limited and boosted 10 DB.

DTS CD's were originally being calibrated wrong ( or correctly, depending on how you look at it) at the studio and were playing back TOO LOUD as the Dolby spec calls for the 10 db boost to be added in the DSP for calibration reasons.

DTS and SACD have it right, both using a full bandwidth .1 channel. it's Dolby who have it wrong by bringing the bandwidth limited LFE channel with the 10 db boost to home theater (only because it's cheaper to transfer their original information directly to DVD).

it's Dolby against the world and the world has to conform to their lesser format. listen to AOTC and tell me the low freqs aren't hot-rodded, point being that how a soundtrack is mixed has less to do with whether or not the format is better.

my original point was that your entire playback system and how you choose to route the low frequencies in it are just as important to how it sounds in the end. most people lose sight of that simple fact.

soundhound's system is of extremely high quality, so his assessment of a comparison is first hand, done correctly and through very trained ears (boblinds included, of course).

soundhound also has chosen to filter the redirected bass and LFE info from his front left and right channels with sub set to 'NO', using a high quality external crossover (which is a discussion for another time). his sub system consists of no less than 4 18" drivers powered by 1,000 watts. i didn't see any mention of the DTS track containing hot rodded bass in the comparison.

in the end, DTS has to conform to Dolby's format. DTS just takes more care in the production of their product. as a result, they sound better. after 36 years in music, no one is gonna fool me into thinking exaggerated eq is the same as better production, or that a cd sounds as good as a well produced multi channel SACD. what DD music video sounds as good as 'hell freezes over'?

Look, you can spout rhetoric all you want, but so far nobody has yet shown any concrete evidence of any kind to suggest that DTS is actually better than Dolby Digital. And unless you can provide that evidence, you're buying into hype just as much as if you bought yourself a brand new Bose system: shopping by name and reputation rather than necessarily by merit.

But I'm not saying that DTS isn't better than Dolby Digital. I'm just saying that there is no evidence to suggest this, whereas it has been shown that DTS is at least less accurate than Dolby Digital in terms of representing the original waveform.

Jeff

P.S. My own system's not too shabby either. And when that 770 arrives tomorrow, I suspect I'll enjoy it even more.

Actually, I no longer have any bass from any channel redirected to my front left and right. All speakers are set to "large" (because they are, well, large). What I do have is the 950 set to "no sub" so the LFE is re-directed to both my front left and right mains. As bosso pointed out, I have an external 60Hz crossover in line with the left and right mains which directs the bass (in stereo) to the left and right subs. This preserves the low bass information in stereo when listening to all sources.



[This message has been edited by soundhound (edited February 26, 2003).]

SH: something i've been wondering...does the pink noise for calibration contain info for setting levels of 'large' speakers, or is the tone the same for 'large' and 'small'?

in other words, does the pink noise have freqs down to 20hz?

i've been reconsidering my stance on all sats to 'large' because of the mode excitation from 5 speakers set at different points in the room. this should be noticed if the pink noise is full range.

as i said...just wondering.

Bosso:

The "pink noise" tone on the Outlaw 950 is the same regardless of speaker setting for the mains, but the subwoofer signal changes depending on the setting of the 950's crossover.

I have output the noise tone of the Outlaw 950, the tone from the Sound & Vision Home Theater Tune Up, and wideband pink noise into my spectrum analyzer so you can see for yourself the frequency distribution of the various signals.

The Outlaw 950 internal test tone: fronts & surround


The Outlaw 950 internal test tone: subwoofer (crossover set to 60Hz)


The Outlaw 950 internal test tone: subwoofer (crossover set to 150Hz)


The Sound & Vision Home Theater Tune-Up


Wideband Pink Noise



As you can see, the tones from the Outlaw 950 and the Sound & Vision disc are heavily biased toward the mid-range frequencies, with very little information in the bass and treble regions, except for the subwoofer test (the low pass of the subwoofer test signal tracks the 950's crossover setting). The wideband pink noise has equal output across the 20Hz to 20Khz band.

You can also see that since the front and surround test tones on the 950 (and all other such pre/pros) cover only a small slice of the audio spectrum (centered at 800Hz), the relative frequency responses of your speakers in this region are very influential on the accuracy of your calibration. If for instance your mains have a hump at the frequency of the test signal, and your surrounds have a dip, the surrounds will end up being set too loud. It is for this reason that to get a really accurate calibration, the use of wideband pink noise is recommended. The "Avia" DVD test disc contains wide band pink noise 5.0 tests for this purpose. Be sure to note that these tones on the Avia disc are recorded at a -20db level rather than the more common -30db, so you need to set your sound level to 85db, rather than 75db SPL.



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The Soundhound Theater


[This message has been edited by soundhound (edited February 26, 2003).]

Soundhound,

Out of curiosity, which spectrum analyzer are you using?

Jeff

It is a software program for Macintosh called "Mac RTA" The sound card is a digidesign Audiomedia.


[This message has been edited by soundhound (edited February 26, 2003).]

Cool beans. I've considered getting a software RTA. Right now, I have the AudioControl one, but obviously, it's not easy to print out copies of the graphs. (I also suspect it's not as tuneable as one implemented in software might be.)

Jeff

The Mac RTA also has an ocilloscope and sound level meter function. It's pretty good, but the program is due for an upgrade. It also has an RPN calculator that allows comparing, adding and subtracting graphs from each other.


[This message has been edited by soundhound (edited February 26, 2003).]

Well, first, I'd probably need a Mac ...

Jeff

My personal habit is to buy fruit from fruit companies, computers from computer companies. YMMV.

TrueRTA is a basic RTA for the PC, and you can get decent MLS stuff from $100 and up.

www.trueaudio.com
www.purebits.com
www.nvo.com

for dispelling dts conspiracy theories:

http://www.wirehedmag.com/archives/00001/sound.html

charlie: as usual the links are right on and appreciated.

Question, does this affect how the 'mix' itself sounds in the final product, - when master volume is less during mixing:

Dolby Digital soundtracks playback several decibals lower than the master volume level due to Dolby’s Dialog Normalization. Therefore, DD is quieter than DTS and the master. So, technically one should be complaining about incorrect master volume level playback on Dolby Digital soundtracks

..or is it just a question of a DD track (if volume is left untouched on your system during playback) being a few dB less than its DTS counterpart?

This is all just AFAIK and etc.....

Dialog normalization is an embedded tag that allows the decoder to 'know' where the level of normal dialog is in a soundtrack. This is helpful when trying to maintain a consistent volume level across a spectrum of different audio programs as well as allowing accurate compression of dynamic range if desired, by allowing sounds louder and quieter than dialog to be compressed to a level nearer the dialog level.

If dial-norm is set correctly all movie (and other programs, such as commercials, etc.) dialog should be at the same level while allowing headroom for loud or quiet passages. In practice a lot of engineers don't set the dial-norm value explicitly in the encoder, so it is generally left in a position (the default value) where the decoder will interpret it as a request to reduce overall gain by 4 db.

So, it is my understanding (possibly all wrong) that it is not the presence of the feature but rather the use (or lack thereof) that causes most DD data streams to be decoded at -4 db.

The Dolby Digital master is always produced on the dubbing stage at the end of the final mix of the film. During this process, the DD master is A/B compared to the 24 bit "printmaster" mix coming directly from the mixing console in real time, with the picture running. I have never heard any volume differences during this comparison; the only difference I routinely hear is a sound quality degradation due to the DD encoding. What this means in practical terms is that at least at it's creation, the DD master has the identical volume level that the film was mixed at. The DTS encoding is always done after the fact, and the film's mixing engineers do not routinely listen to this master.

As an aside, film mixing consoles do not have a "monitor volume" control that sets the playback sound level that is heard. The volume of the film is literally controlled by the engineers mixing the various sound units to a volume that is "appropriate" and what the film's director wishes. Some want their films mixed louder, some not so loud. But at any rate, on a film console (unlike a traditional music recording console), the volume level of the mix you hear is literally what it will be in a cinema.

[This message has been edited by soundhound (edited February 26, 2003).]

Here are some links:

http://www.smr-home-theatre.org/optimode/page3.html
http://www.dolby.com/tech/

BoB:

Thanks for the kind words regarding links - glad they helped.

The article on WireHed wasn't really definitive on a lot of issues IMO, pretty much seemed to follow the usual 'it sounded better to me, and here are some facts' format. Nothing really new or different. They handily omitted some facts too, like the question where the 0.6 db boost on the DTS 'shootout' CD came from and the fact that DTS hits -3db at 15khz and 754 kbps (the typical DVD rate) among others.

My take on it is that DTS may sound better (from my experience) but whether it's more accurate or not is not proven and in any case it does have issues of it's own AND consumes a truly hogish amount of bandwidth compared to the rather small improvement over DD.

I'd like to see DTS at 448 kbps, but I doubt the codec could produce anything worthwhile at that datarate. I bet a codec with the efficiency of DD and a higher datarate, maybe just an AC-3.1 where higher datarates are defined would beat either current solution. I'd also like to hear what Dolby 'E' (2mbps datarate) might sound like, but I doubt consumers will in the near future.

D.D may be more accurate to the master, and without hearing comparisons myself I just have to take people I trust, (Like SH’s) word. But the reason I was asking the volume question is that repeatedly seeing that argument that DTS is recorded hotter so we simply perceive it as ‘louder = better’ has always confused me as to its merits as a valid point. I have a comfort zone for my ears regardless of the media or version that I constantly adjust for. If I’m ready to ‘dig in’ to a movie and it’s not to late, regardless of the ‘level’ it was recorded at. I will set it to the level I wish to experience. So unless the adjustments such as Charlie’s links on how the DD decoders are set to compensate dB levels particularly on THX equipment, or on the dubbing stage itself ‘Dialogue normalization’ factors in a manner I’m not grasping.

Don’t I just tend to up my dB to the level my ear ‘likes’ for DD.
And pull it back if it’s overboard on a DTS version.

My volume knob is not fixed beyond my control. I set the level so how should that factor into equating that I simply might be choosing DTS as a preferable solely because its recorded louder?

You probably prefer the DTS because it does sound better. I preferred it myself. The point I have been trying to make (and what was borne out at the DTS vs DD shootout I participated in with the "Terminator II" reel) is that beyond the hype, smoke and mirrors, they both can be accurate to the original master when they have to be. I know that DD degrades the sound, and there is no reason to think that DTS doesn't also do so, but probably to a lesser degree.

From a marketing point of view, it is necessary that your product stands out from the competition. Whether DTS does this by actually sounding better, or by manipulation of the master or a combination of both, only they know for sure. All we know is what they say, and barring the opportunity of taking a sound file to DTS for encoding and then doing a comparison to the original, the debate is bound to continue.

[This message has been edited by soundhound (edited February 26, 2003).]

Interestingly that is possible, since (if I understood correctly) the DTS CAE-4 encoder has been available to studios (and maybe the public, with enough $$$ ?) since 2000, so it seems like an interested 3rd party could hold a thorough shootout, if motivated and backed.

EDIT: [added link]

http://www.dtsonline.com/proaudio/cae4.html


[This message has been edited by charlie (edited February 27, 2003).]

I have not seen a DTS encoder at any studio sound department I've been at, but then again, I'm usually not concerned with sound lay-back issues, and haven't specifically looked for one. I'll make it a point to ask to have a file encoded if I do get the chance. I still haven't purchased the Dolby Digital encoding software because I haven't had a request for a DD encoded copy a music soundtrack yet.