Yesterday, I had bobliinds and his lovely wife over to watch LOTR, "U-571" and "Gladiator" in DTS, in comparason to Dolby Digital. My Sony DVD player does not pass the DTS signal, so I wanted to listen for any differences. He brought his DVD player and we plugged it in. I have heard DTS before, and am familiar with it's effects, but not in my home theater setup.

Was there a difference? Yes., very definately, and for the better. But there are some important things I noticed.

The most obvious was an increased sibilance to the entire sound presentation. This should not be an artifact of DTS per se, and it almost certainly had to have originated somewhere else in the conversion to DTS.

Another thing that I heard was that the surrounds were higher in level. This was not just a subjective judgement. I have monitoring meters on each channel for when I do mixes, and the difference could clearly be seen. The level difference was probably around 3db.

The overall mix sound level was also a few dbs higher in the DTS than the Dolby Digital.

The DTS had a more fluid sound presentation, and preserved more of the partials of the voices, instruments and sound effects.

However, I am very "imprinted" with the sound that is heard on a dubbing stage, having heard the original master sound "units" of various films on an almost daily basis, and based on this, I would have to say that the Dolby Digital version was closer to the sound that was originally heard when the film was mixed. The DTS by comparason, while soundng preferable, sounded "enhanced" over what it should have.

Then we performed an extremely interesting comparason. Having performed the restoration of the music for the DVD of "Superman" I have the original 24 bit masters of the music for the film on hard disc. On the DVD, there are several un-cut pieces of music from the score I supplied as bonus material, that are encoded in Dolby Digital. We decided to compare the two.

This was an especially valid comparason since I mixed the music for these tracks in my home theater, and on my speakers. I supplied the DVD authoring studio (Warner Bros Studios, Hollywood) with digital 24 bit files of my mixes to be encoded for the DVD. This is significant as the geneology of the journey from mixing studio to finished DVD is completely known. The mastering engineer was given strict instructions by me to do nothing to these tracks other than encode them into Dolby Digital for the DVD.

So we cued up the bonus tracks on the DVD with their original 24 bit masters residing on my ProTools digital audio workstation. The switching was performed by an 8 channel mechanical (nitrogen filled with gold contacts) relay, so no added electronics were in the signal chain.

Differences? DUHhhhh!! This was not a subtle comparason. The most glaring difference to me was that all the "partials" of the musical instruments were stripped away below a certain threshold, and replaced by what sounds like "sandpaper". This was really bad. The 24 bit masters on the other hand sounded full, rich, and smooth all the way up and down the tonal range, regardless of subtleness of the details. It sounded like music, with no grittiness added. Instruments like trumpets and trombones especially had the subtle detail of their harmonics preserved, where they sounded like "grit" on the Dolby Digital version. Not surprisingly, as the music got denser and louder, the worse the Dolby Digital version sounded when compared to the pristine 24 bit master.

Perhaps an even bigger suprise was that the dynamic range of the Dolby Digital version was severely limited. This was not a subtle difference, but one that was so obvious that I had to ride the volume control of the Dolby Digital to keep the volumes equal on loud passages!

Bobliinds and his wife were able to tell which version was playing 100% of the time: the difference was that obvious.

This comparason is enlightening since we can only hear the finished soundtrack on DVDs and in movie theaters in Dolby Digital or DTS (or sometimes SDDS) - there is no alternative!. And make no mistake, DTS is a lossy medium too: not as bad as Dolby Digital, but nowhere as pristine sounding as the uncompressed masters. I have taken the "sonic penalty" of both of these compressed formats for granted, since I hear their results regularly, and have as a reference the sound of the original masters, but with nothing to compare to, the average listener has no idea how comprimised these formats are. I'm afraid that until motion picture soundtracks are delivered on some future format uncompressed, we are going to have to live with less than optimum (to put it mildly!) sound.

Perhaps Bobliinds would like to chime in on his thoughts about this comparason.


[This message has been edited by soundhound (edited February 07, 2003).]

[Phew. FINALLY I got around to getting rid of that extra i in "bobliinds" Jeez, one lousy typo and it follows you around for life.... ]

For my part, this little test that SH and I did was startling. Although I have always tended to prefer the DTS mixes on DVD's, I was in the "six of one, half a dozen of the other" camp as far as comparative quality was concerned. "Different, but a tossup" would characterize my POV.

After yesterday, I will now decisively say that DTS sounds better than Dolby Digital.

In fact, the kinds of differences I heard in our comparisons between DTS & DD reflected many of the characteristics I heard comparing SH's masters with the DVD (although, frankly, the masters vs. DD5.1 differences were MUCH more extreme - see below) That is, the DTS typically had more dimensionality; more "roundness" to individual voices, instruments and effects; more of a sense of "place" acoustics -- which is an illusion in film tracks, of course; and more subtle detail in the timbre of sounds.

Comparing the masters and the DD5.1 DVD is not an experience that HT audiophiles should have. It was just plain heartbreaking and will forever change your level of satisfaction with the audio on commercial DVD's. (Here's another metaphor: You know how after having sex for the first time, you're never satisfied with "making out" in the back of a Chevy? This was like that...)

SH did a SPECTACULAR job refreshing those original score tracks. To hear his ProTools masters in his reference studio is a revelation -- full bodied instrumental timbres; rich, involving surround acoustics; and stunning overall impact from crisp transients to ballsy low end.

Going from that to the DD version was like moving from CD to Dixie-Cups-And-String.

OK. So maybe it wasn't THAT bad; but it was a HUGE difference. Maybe it's more like the difference between FM Stereo and AM Stereo radio. (Comparing only the nature of the difference, NOT the actual quality of the sound, if that makes sense.)

Where the master was big and imposing, the DD was flat and one-dimensional. And the DD5.1 dynamic range compression in the big volume sections of the music was shameful. I suggested loading the gun on the wall of SH's New Mexico-themed studio and taking it over to Dolby Labs. SH wisely talked me out of it.).]

[This message has been edited by boblinds (edited February 07, 2003).]

[This message has been edited by boblinds (edited February 08, 2003).]

I would agree the DTS is better than DD. I have played a number of tracks to hear the difference. My favorites are Blade II, DTS ES puts the DD ES to shame. And rented Reign of Fire once and during the beginning scene when the boy is in the cave and the drops of water are individually occurring in surround, the DTS sound reproduction of these drops was superb and real and the DD made the drops lose their spatial placement.

While at CES I picked up a demo from AIXrecords.com, new recordings in 96Khz/24bit at DD5.1 or DTS. They sound great, even the wife thinks so. The DD/DTS comparison is a little tougher to make out in this instance, but I still find the clarity of the DTS track better defined and separation/imaging of sounds better as a result. At $25 per CD, these new DVD discs play in your everyday DVD, but I am just being patient before I pick up a few more for my listening pleasure.

on some future format uncompressed is anyone working on this? …or are the masses just doomed to continue never realizing what they are missing?

Listening to DVD’s like the Matrix, can bother me If I’m paying attention to scoring in the movie…no one denies the impact of pumping that DVD through a good HT system. But if you take the time to ‘listen’ to sound particularly in the busy overlaid passages, (the big lobby battle) really the ‘sound’ stinks, -there’s a lack of quality to the thumping score which is hard to even notice overlaid as it is with gunfire. It’s fun it’s loud but it not musical.

I had early decided (for me) I much preferred DTS for movies, and purchase this whenever possible, nice to hear 2 “sound guys’ impressions on a comparative listening on that topic.

The DTS by comparison, while sounding preferable, sounded "enhanced" over what it should have.
Could it be due to interactions of psychoacoustics that DTS often tends to be preferred? Due to those ‘enhancements’ faintly creating an illusionary effect of a more ‘lively’ presentation. Crudely beefing up the strangulation of sound occurring due to compression?

Going from that to the DD version was like moving from CD to Dixie-Cups-And-String.
. Hes no gentleman, he aint, to interfere with a poor girl (which one of you is Colonel Pickering and which Henry Higgins?) LIZA [snatching up the [original 24 bit masters], and hurling them at him one after the other with all her force] There are your [original 24 bit masters] And there. Take your [original 24 bit masters]; and may you never have a day's luck with them! Theres a pare of blokes menners f' yer! Eed nowed bettern to spawl a pore gel's hapeniss with jest ole DTS ad DD. Will ye-oo Ah-ah-ah-ow-ow-ow-oo!

(I don’t ever give the impression I’m jealous of others having opportunities for such fasinating audio experiences. Do I? )

Lena:

There are a lot of ways that a soundtrack can be manipulated. These can range from simple equalization, to compression, to use of the "signal optimizers" that FM stations use in order to maximise the "loudness" of their signal. I doubt that DTS goes to the extreme of the last approach, but I did document without a doubt that the surrounds were louder and the overall level was higher in the DTS version. These alone would give the impression of a more "enveloping" soundfield, and more subjective "punch", compared to the Dolby Digital version.

I really wish that everyone on this board could have participated in the comparison that we did between the data compressed version and the original source master. It would have given a greater appreciation to the tradeoffs involved with the compressed formats. I hear those masters on a regular basis, so I am somewhat jaded, but I wish more of you could also have that reference.

I doubt that there will ever be available the uncompressed soundtracks, simply because of the high data overhead involved. That's a shame, especially when spending a lot of money to get the best sound quality possible, to have a comprimised sound in the first place.

If there ever was an argument for the existance of DVD-A and SACD, this was it!


[This message has been edited by soundhound (edited February 08, 2003).]

It is possible that in the very near future with Blu Ray being released, that movie soundtracks could be done without lossy compression. The Blu Ray DVD disc can hold something like 27.? gigs (compared to the red laser 4.? gigs). This could make watching DVDs a whole new experience.
What will the future hold?

I get to be Henry!! Me. Me!! I get to be Henry!!!!

Hear at home and on the air
Dropping partials everywhere
Playing masters anyway they like.

They say that it sounds "Just Swell."
Flute or oboe? Who can tell?
Just one more oscillographic spike.

Why can’t the Dolbys leave their data uncompressed?
They say it’s fine. I’m telling you the Emperor’s undressed.
If our throats were Dolby crunched
Then mankind, one and all,
Would sound just like a poor long distance call.

[This message has been edited by boblinds (edited February 08, 2003).]

I wouldn't hold your breath. I doubt that the bitrate could never be high enough to accommodte the high defination video (which they would almost certainly be) and the audio. Uncompressed 24 bit 6 channel 48Khz sample rate audio has a bitrate of about 6.9 megabits per second. That's a good sized chunk of the entire 10 megabit per second data rate on current DVDS for video and audio. High defination video would without question need to be compressed and it's unlikely they would leave the audio uncompressed.

[This message has been edited by soundhound (edited February 08, 2003).]

I agree with SH. I think data compression for audio/video is now a fact of life -- as well as a real world necessity. Larger storage media would allow somewhat higher bit rates; but, as SH says, we ain't gonna be seeing/hearing full bitrate A/V in a home format in the near future, if ever.

We can hope, also, that increasing (and increasingly affordable) computing power might inspire companies like Dolby and DTS to develop more sophisticated compression schemes that would reduce the audible degree of loss.

The artifacts that SH and I were hearing in the DD5.1 compression of his masters WAS NOT SUBTLE. In fact, to my ears, it betrayed a fairly primitive compression strategy.

While I'm not aware of the degree that Dolby has improved their compression algorythms over the ten years or so of DD5.1 (SH probably DOES know this), I suspect more could be done.

I do know that compression has gotten way more sophisticated from the late 1980's when this technology started to look viable. It's unfortunately unavoidable when you're throwing away as much as 90% of the data (!) that something gets lost along the journey.

It is ironic that in the Laserdisc days, we actually DID have uncompressed audio, although with ProLogic encoding.

We're taking giant steps BACKWARDS in some ways......

[This message has been edited by soundhound (edited February 08, 2003).]