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.
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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.