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Author Topic: Dolby Digital vs. DTS Antonio Marcheselli Phenomenal Film Handler Posts: 1260 From: Florence, Italy Registered: Mar 2000 posted 12-28-2003 06:14 PM                        I know few, very few people here in Italy that knows how to align correctly a DTS. A simple thing, just set the levels, but hard to found done correclty... When the room is correctly set, the difference between DTS and DD is minimal. There is, but is just the difference you can found between a 160 and a 192 MP3 (perhaps not the best example!). If you hear a LOT of difference between DD and DTS there is something wrong in the auditorium. And do not compare DTS with DD using different screens, or different films! Bye A  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 12-28-2003 06:23 PM                     I can generally hear the difference between DD and DTS. One has a characteristic sound in the HF department (as in I can generally tell you what digitial I'm listening to if the speakers have a good HF response). I would not use the 4670D as my reference speaker...the 2380 horn is very much a compromise as compared to the 2360...in fact the 4670D and the 2380 horn are not THX approved. The 4675 is the JBL reference speaker. As to using a 3-way over the 4675...the 3-way depends heavily on the xover used and has an inferior response (the HF drops like a rock above 12KHz). Whereas I can hear the difference between DTS and DD on just old-stock A-4s (Multicell HF sections with 288C drivers)...I don't buy you need the lastest to hear it. Steve  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 12-28-2003 06:34 PM                     Steve, Thats really my point by using the 4670D as a for instance speaker and as a result there would be little differences heard. In the many areas I travel to this is a common speaker to find installed. While a good three way would easily exhibit the diferences in the two systems. No matter what system it is though it need to be correctly aligned. Antonio said.... "If you hear a LOT of difference between DD and DTS there is something wrong in the auditorium. And do not compare DTS with DD using different screens, or different films!" That is only true to a point. Sure, there might be something wrong, but on the other hand if these huge differences you've heard are at a very reputable theatre then you might just be listening to a system with very high reasolving power which is located in a room with a very low NC level. At any rate if there is no spectrum analyzer of some stagdard brought in to check up then no one would ever know what is going on. Typically I find that there are little differences between digital playback systems when the B chain is a two way system, but with a good three way system the differences are definately there. Mark  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 12-28-2003 06:55 PM                     I don't buy that either that you have to have certain speakers or the R2. So long as the two formats are being played at EXACTLY the same level and both formats are going through the EXACT same B-chain, it doesn't matter if the EQ (or other factors) is off a bit or not. The test is still fair. Also, no group of customers are going to pay to watch a movie with only the LEFT channel playing, so tests like that doesn't matter when it comes to choosing a system.  |  IP: Logged Antonio Marcheselli Phenomenal Film Handler Posts: 1260 From: Florence, Italy Registered: Mar 2000 posted 12-28-2003 06:55 PM                        Mark, Yes, that's what I mean! A bit OT: I noted too that three way systems had lower freq. response. Why? Shouldn't have three way system improved frequency response? Steve One of the theater I worked for had poor acoustic quality on the very high frequencies and had JBL 4670D speakers. I can always say if the DTS was playing since the high frequencies sounded a bit harsh! But in another theater, better acoustic, I loved that clarity and brilliant high frequencies!!!!! Bye A  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 12-28-2003 07:05 PM                     Brad, Aside from performing this test for ones self to hear this interesting SRD artifact I also couldn't imagine only running the left chan. for a paying audience. Its only fair when making critical comparisons to know that the rest of the system is performing properly.... Why would anyone ever want to assume anything in regards to this sort of thing? Mark  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 12-29-2003 12:05 AM                     The fact that DTS can amintain the channel seperation in a discrete fashion which is something SRD fails to do during complex sound portions shows up the most in a theatre with wide speeker seperation Also one are DTS does have a benifit is at the high end  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 12-29-2003 08:48 AM                     To be hypercritical of DTS...The surrounds have nothing below 80Hz and the subwoofer has nothing above 80Hz since the surrounds and subs share the same channels...DD does not have that particular problem. So to do a single channel test on any of the digitals to prove/disprove its capability is a bit of a false test. Steve  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 12-29-2003 10:52 AM                     A test of any of the front channels would be very revealing. I actually prefer the surround channels the way that DTS designed them. There can still be surrounds and SW at the same time too...with the sub doing what its intended to do and the surrounds being band limited in the very lf area is actually a good thing. The typical JBL, or EV surround could not reproduce much high level below about 80 hz anyway. And those surrounds that attempt to reproduce below around 80 hz from a DD track are actually wasting power. Typically, attempting to make many types of surrounds reproduce info below 60 to 80 hz also drastically increases harmonic distortion from the woofer. These 8" to 10" woofers cones were not designed for lots of output below that and will end up absorbing alot of excess LF power in their voice coils. To me DTS appears to have thought out its design to be more practical for the surround channels than did Dolby. Mark @ CLACO  |  IP: Logged Scott Jentsch Phenomenal Film Handler Posts: 1061 From: New Berlin, WI, USA Registered: Apr 2003 posted 12-29-2003 01:37 PM                        One aspect of operation that no one has mentioned is how well the two systems perform in less than desirable conditions. How do they perform over the splices, done well or not-so-well? Back in the mid-90's, that's the way I could tell if it was DD or DTS, just watch for the reel change and listen for the splice. DD would drop out pretty reliably (at least at the Marcus theaters here in WI), and DTS didn't present them with that problem. Eventually, they must have figured it out, since it's very difficult to tell which sound format is used by that measure. Although, at a recent screening of one of the LOTR Extended Editions, the sound dropped out (completely, no analog either) at every splice, so something must have been done to screw it up. How many frames can each be missing before dropping back to analog or dropping out? As far as the discs go, my theory is that the new hard drive-based models will drive down the dependence upon every print having the discs included as they should. Theoretically, they could begin supplying disc images via the Internet for those theaters that are missing them for a particular movie. Two discs only take up about 1.5GB, which is possible for a broadband connection to download between the time you notice the missing image and when you run the feature. Aside from that, if you're missing DTS discs, isn't that an issue with your distributor? Shouldn't they be inventorying what they are sending out, and then also the prints coming back from theaters?  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 12-29-2003 03:45 PM                     Scott, On at least the latest DA-20's there is about a 4 second buffer of audio stored in the player so splices and minor damage to a frame here and there shouldn't affect the playback much, same for the DTS playback....4 seconds of audio is stored in its buffers. In fact a customer in Ketchum, ID had gotten 3 defective reels of The Last Samauri. Reel one was the worst with the green time code light constantly blinking on and off for just about the whole reel and amazingly the audio only defaulted a couple of times and then went right back to digital during very long dropouts of time code. I'd bet that time code was only being read on the average for one second on and two to three seconds off.....it seemed to come though in spurts from reel 1. DTS certainly has that part of their system nailed in place and that reel was one of the best demo pieces as to how well the buffer works! After I did a peoper "A" and "B" chain on their system it was difficult to tell when it reverted. New reels arrived a day later and they ran for 4 showings that way with no complaints. This sort of test would have been interesting to do with the new XD-10 to see if its as good at keeping up with things. Dolby is also at least this good in their buffering system but you cannot be missing more than 4 consecutive blocks of data, or one full frame for it to not revert to analog. Another thing I've noticed with Dolby is that they have been doing continual inprovement and upgrades to the boards in the DA-20. Some of the latest boards barely resemble the earlier versions and the DA-20 seems to give the most reliable DD playback...more so than either the CP500 or the CP650. The 650 would be second best though for reliable DD playback. Mark  |  IP: Logged Antonio Marcheselli Phenomenal Film Handler Posts: 1260 From: Florence, Italy Registered: Mar 2000 posted 12-29-2003 03:52 PM                        Mark 4 seconds of buffer for DD? On ky Dolby Digital installation splices are always present in sound. Nothing terrible but a little glitch in the sound is always present (and the CP doesn't revert to analog). DTS handles splices much better. Bye A  |  IP: Logged Manny Knowles "What are these things and WHY are they BLUE???" Posts: 4247 From: Bloomington, IN, USA Registered: Feb 2002 posted 12-29-2003 04:20 PM                     Scott: Theoretically, they could get the discs to ship with the movies. Theoretically, mind you!  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 12-29-2003 04:26 PM                     You guys must not be calibrating your SRD readers properly. A dropout at splices? NEVER! And I even run all screenings with the analog exciter/led turned off, so I know that no matter how good the A-chain on the optical is that the dropout would be heard. For that matter, I have my optical in the screening room set up on it's own breaker and I never even turn it on unless I am running an analog film, and some of the prints that go through there are abused. Anyway, I don't believe that I am that lucky or overly skilled at aligning the SRD readers. Likewise I don't believe you guys are not aliging them up properly. I can use opaque yellow tape and even with that there is no dropout. Maybe Utah is the Bermuda Triangle of SRD. Something is amiss here.  |  IP: Logged Antonio Marcheselli Phenomenal Film Handler Posts: 1260 From: Florence, Italy Registered: Mar 2000 posted 12-29-2003 04:34 PM                        Brad, I didnt say dropout. I say that you can hear where are splices when in SRD. A Good printed film and a well aligned reader does minimize the problem but I can always hear the splices. Bye A  |  IP: Logged

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