This is topic Cinemark, SR-D, and Subwoofers in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by David Stambaugh (Member # 1102) on 04-09-2002, 01:12 PM:
I've noticed that the local Cinemark's SR-D houses have very weak .1 LFE. Basically no deep bass at all. Yet their DTS houses seem much better in low-end performance. Brad noted the same thing in another thread (might be the one about Cinemark policy trailers). A Cinemark engineer says all systems are working to "industry standards" and are checked regularly (surprise!), also that competitors may be "goosing" their systems, implying they are NOT properly configured.How can there possibly be that big a difference in SR-D vs. DTS unless something is wrong? Or am I smoking crack? Obviously Cinemark believes the latter. 
[Of course my real agenda with this post is that somebody from Cinemark will read it, recognize the problem, and know what to do about it.]
Posted by Ken Layton (Member # 133) on 04-09-2002, 04:32 PM:
Could also be that one or more of the subwoofs have been stolen in the Dolby Digital houses.
Posted by Darryl Spicer (Member # 711) on 04-09-2002, 06:09 PM:
Or blown out because of the way they are hooked up...but I am not sure about this purticular theater. Some of them have all three systems in the same rack. some have only two of them and others have just one of a purticular brand.
Posted by David Stambaugh (Member # 1102) on 04-09-2002, 06:55 PM:
What's weird is it seems like all the SR-D houses there have no subwoofer action, but the same location's DTS houses all definitely do have working subs. The difference is very noticeable.
Posted by Richard Hamilton (Member # 321) on 04-09-2002, 08:51 PM:
It's been awhile since I set up a 35mm house, but if I remember correctly: when you set the levels on DTS, you set the Sub level +10db. I think the same goes for SRD. I remember setting the levels in the CP500 that the sub output was +10DB also.It's been awhile 
, please correct me if I'm wrong,
Rick
Posted by Steve Guttag (Member # 268) on 04-09-2002, 09:26 PM:
David,What was the "host processor" to the Dolby digital houses or was it a CP-500/CP-650?
Likewise, what was the host processor for the DTS or was it the DTS-6AD
Steve
------------------
"Old projectionists never die, they just changeover!"
Posted by Bobby Henderson (Member # 840) on 04-09-2002, 10:02 PM:
I think what is happening with some of those Dolby Digital equipped Cinemark auditoriums is just an odd coincidence. I have been in plenty of DTS-equipped Cinemark houses that greatly lacked deep bass. I suspected blown subwoofers or a completely out of tune sound system. I watched "Rush Hour 2" at a new Cinemark/IMAX 3D build in Colorado Springs and was very disappointed by the sound quality. I could see through the port glass and tell the DTS player was working, but the audio was really no better than an average analog presentation.
Posted by David Stambaugh (Member # 1102) on 04-09-2002, 10:11 PM:
Steve, I don't know the answer to that. Maybe Darryl Spicer knows. It would be the standard Cinemark package & configuration as of early 1999. They might be running Ultra-Stereo throughout. I could ask the GM except I think I'm on his sh*t list now.I am absolutely convinced I'm right though.
Posted by Brad Miller (Member # 2) on 04-09-2002, 10:21 PM:
David, the Cinemark Webb Chapel is exactly like what you describe, although I'm not sure why the pattern is always that way. (Then again I've not heard a good sounding Cinemark theater since the days when they supported THX.) SRD runs through CP500s at all new Cinemark locations and CP65s on older installations. DTS always runs through Ultra Stereo.
Posted by Darryl Spicer (Member # 711) on 04-09-2002, 10:57 PM:
All we run down here is DTS and they all seem to put out good sub bass. But like I said earlier. This theater may be using a Combo digital set up. I will ask our tech if I think about it the next time I see him.
Posted by Karen Hultgren (Member # 395) on 04-10-2002, 01:04 PM:
The SMPTE standard (RP200)states that the digital subwoofer level be set for 10dB in-band gain (as compared to the center channel). All digital systems can and should be set to this standard.Karen at DTS
Posted by David Stambaugh (Member # 1102) on 04-10-2002, 01:33 PM:
Karen, the good news for you is the DTS-equipped houses sound pretty good. Darryl, by "combo digital" I assume you mean capable of multiple digital formats on the same screen? That's not what they have at this theater. Each is either DTS or SR-D, but not both, split roughly 50-50 among the 17 auditoriums.
Posted by Ethan Harper (Member # 472) on 04-10-2002, 06:05 PM:
I guess they need to install their Cinemark Super Dee Duper Mega Digital Sound System.------------------
--"That's my story and i'm sticking to it!"--
Posted by David Stambaugh (Member # 1102) on 04-10-2002, 07:00 PM:
Peering in through the booth glass in a DTS house, it looks like a DTS 6D player and an Ultra-Stereo JS-200 processor. From a distance anyway. That's all I could identify. The surround speakers are JBL, not sure of the model but they look like the ones commonly found in many theaters, including THX-certified.
Posted by Darryl Spicer (Member # 711) on 04-10-2002, 10:18 PM:
Should be a jsx 1000 wich is a 200 at the max capability. yeah that was what I was refering to when I said Combo. one thing you have to remember about DTS is that the subbass channel is carried over with the surround channels. So the bass can be present some in the surrounds.
Posted by Karen Hultgren (Member # 395) on 04-11-2002, 11:43 AM:
To claify DTS subwoofer in the surrounds: In the standard 5.1 mode, the DTS surrounds carry some subwoofer material, all above 80Hz. There are filters in the surrounds that only let signals from 80Hz and above pass. The subwoofer material, from 80Hz down to 20Hz, is routed to a separate output channel on the DTS player.
Karen at DTS
Posted by David Stambaugh (Member # 1102) on 04-11-2002, 11:53 AM:
The really deep, low-freq. bass I'm talking about can only come from a subwoofer. The surrounds can't go that low (by design). When I saw "The Rookie" there yesterday, in a DTS house, it had some of that really deep, low-freq. bass, the kind that none of their SR-D houses seem to ever have.
Posted by Antonio Marcheselli (Member # 373) on 04-12-2002, 02:40 PM:
Correct me if I'm wrong: since DTS Subwoofer level is separate from Dolby Digital Subwoofer level, I believe that you can set a sound system with poor DD subwoofer and great DTS subwoofer and Viceversa.Bye
Antonio
Posted by David Stambaugh (Member # 1102) on 04-14-2002, 05:51 PM:
A former insider at Cinemark 17 who was there during the initial installation and calibration tells me that all the subs were turned way down to eliminate sound leakage to adjacent auditoriums. Isn't that special. This person also says all speakers are JBL throughout; there are 4 [apparently virgin] subwoofers in each house; the Dolby houses all have CP500 processors; and QSC amps are used throughout.
Posted by Neil Hunter (Member # 1005) on 04-15-2002, 12:20 AM:
David,Cinemark uses all QSC amps and JBL speakers for their newer theaters(98 and up, I believe). They used peavey amps for their older theaters. The brand of speakers escapes me at the moment.