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Author Topic: STAR WARS LFE SOUND ISSUE? Christopher Lani Film Handler Posts: 62 From: Ely, Nevada, USA Registered: Nov 2013 posted 01-02-2016 03:37 PM                        Has anyone else experienced any overloading or Sound distorations during the scenes were the bad guy is using the force to get info out of the characters. I'll give some exact times, but it only happens a few times every showing. I do have a older system but I have not experienced this kind of distortion before.happens at 1:23 and 2:04. Thats how's and minutes. Speakers have been checked and otherwise the sound is fine.  |  IP: Logged Sam D. Chavez Film God Posts: 2153 From: Martinez, CA USA Registered: Aug 2003 posted 01-02-2016 04:13 PM                       Define "older". Dolby, USL, Smart? Model too. Film, SR.D or analog? Digital, etc.  |  IP: Logged Christopher Lani Film Handler Posts: 62 From: Ely, Nevada, USA Registered: Nov 2013 posted 01-02-2016 04:31 PM                        Jesus. I accidently posted this question in 2 forums and I get spanked? Anyways, Dolby CP750 sound, QSC Amps and re coned EV Speakers.  |  IP: Logged Stephan Shelley Jedi Master Film Handler Posts: 854 From: castro valley, CA, usa Registered: Nov 2014 posted 01-02-2016 04:36 PM                     Bi-amped? What crossovers?  |  IP: Logged Jim Cassedy Phenomenal Film Handler Posts: 1661 From: San Francisco, CA Registered: Dec 2006 posted 01-02-2016 04:46 PM                     It's very interesting that you should post this question. The first weekend the movie opened, I got a call from a theater that some people were complaining about a "sound problem' in parts of the movie. But they weren't specific. Nonethless, I went down there early the next morning, went completely through their sound system and could find nothing wrong. And now, the theater where I'm running HATEFUL 8 in 70mm has has had numerous complaints about some sort of 'sound problem' since they moved the Star Wars flick into a different auditorium last week. The complaints were too vague to pin down, and spot checks of the audio by the theater staff, and even the manager, didn't expose any problems. Yesterday, the manager got an e-mail from some guy from LucasFilm who went to one of the shows here and he complained that it sounded like "the subwoofer was blown" Just because it's been causing them problems and I wanted to help them out, I came in early this morning with signal generators, DCP Low Freq tests and an RTA- - and everything checked out OK. I even crawled under the screen and physically checked the subwoofer, and all the other speakers and they were all OK and in good shape. I was beginning to suspect that perhaps something in the room or backstage was resonating at low freqs and causing a 'distortion effect' or something. But now that I read your post, I'm beginning to think that mabye there's some weird low frequency harmonics or other anomaly in the sound mix that some systems just can't handle, although they are otherwise working OK. System here is digital (DCP). Processor is a CP-750. I forget what type of subwoofer was back there, but the amps are QSC 1400's. >>One Question about your time points: Is that the actual running time from the start of the movie, or do those timse include any traiers or pre-show stuff you had in your playlist THANKS! -jc-  |  IP: Logged Stephan Shelley Jedi Master Film Handler Posts: 854 From: castro valley, CA, usa Registered: Nov 2014 posted 01-02-2016 05:37 PM                     Were both the 15" woofers as well as the subs reconed? EV cone type drivers have a bad habit of coming unglued from the outer ring. It can be subtle and hard to spot.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 01-02-2016 06:19 PM                     Sounds like the diaphragm in the HF horn is clipping, and could be starting to crack which would create the distortions. Why the question on bi-amp since the horn should be only getting high freqs where the lower speakers gets the other. If a crossover system isn't doing its thing, the low freqs are heading up to the horn making that driver go insane which it's not designed for such and can easily take a HF driver out. Two weeks ago, I lost a center horn. The diaphragm had indeed opened up. I moved the driver from left channel to center channel to get my sound back to normal. When I got the replacement driver, the new one went to the left channel.  |  IP: Logged Stephan Shelley Jedi Master Film Handler Posts: 854 From: castro valley, CA, usa Registered: Nov 2014 posted 01-02-2016 07:08 PM                     Monte, just to get a complete idea of the system. I don't think it has been isolated to the HF drivers yet, but certainly a possibility.  |  IP: Logged Jim Cassedy Phenomenal Film Handler Posts: 1661 From: San Francisco, CA Registered: Dec 2006 posted 01-02-2016 08:10 PM                     I checked their system here with frequency sweeps, pink noise, etc, and everything looks absolutely normal on the RTA. I ran about 20min of the movie this morning, louder than normal, with scenes that included both quiet dialogue, as well as a few 'battle scenes'- - and I heard nothing out of the ordinary. But they've gotten too many complaints to ignore this. And I'm aware of three different theaters now that have seem to be experiencing the same issue. That's why I say I think there's some weird thing in the sound mix in some scenes that some systems just can't handle for some reason. They've never had any sound complaints in that auditorium until they moved Star Wars there last week.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 01-02-2016 08:11 PM                     Remember, when you are doing your testing, that you are using a reference signal that is at -20dB, typically so a problem that doesn't show itself at that level might be a real problem at 0dBFS. I've found MOST subwoofer systems underspecified in my career. That is, if you do the math, if the theatre is played back at reference level (and that is a big "if") then there is no way the subwoofers/amps can handle what might be requested of them. If you have less than a double-18" system in all but the tiniest of rooms (and I mean something like 30-foot deep rooms) you are going to run out of sub. It is not unusual to need four or eight 18" subs to properly handle a typical "large" house in a normal sized room. Remember too, more subs equals more efficiency. It is often better to add more subs than more amplification. When judging subwoofer power handling, you HAVE to use continuous pink noise not the bogus "program" power or even more bogus "peak" power. You can use program for stage and surround channels but never subs. Sub's signal more closely resembles pink noise and you don't know what its duration is. Think "Apollo 13"...the sub signal can be quite protracted and if your subwoofer runs out of mechanical range, it will kill itself. Likewise, either your amplifier(s) can or can't handle the demands on them.  |  IP: Logged Marlon Martins Film Handler Posts: 78 From: Torres, RS, Brazil Registered: Apr 2015 posted 01-02-2016 09:43 PM                     i saw the SW-TFA 3 times now, and the "force" scenes really pushed the subs. feels like its giving too much variance on low frequencies and the sub is distorting a bit. but after a sub died a while ago, we split the power between two of them, and the audio is passing on a compressor, using only the limiter function. so it's much more "safe" now. but i can see how would be easy to distort on that scenes, as look like the sound "intensity" are more than usual. (special on Rey and Kylo Ren interrogation scene)  |  IP: Logged Frank Cox Film God Posts: 2234 From: Melville Saskatchewan Canada Registered: Apr 2011 posted 01-02-2016 11:51 PM                        Jim: Why don't you sit down and watch the WHOLE MOVIE in that auditorium instead of bits and pieces? That way you'll find out exactly what the audience is hearing and that will take a lot less time and effort than fiddling around with test equipment and whatnot. After you have heard the problem for yourself and know where it's located in the movie, then you can drag out the test equipment and you'll know what to look for. If you watch the whole movie by yourself late at night or early in the morning when nobody else is around you'll be able to find out what's really going on instead of making guesses.  |  IP: Logged Jim Cassedy Phenomenal Film Handler Posts: 1661 From: San Francisco, CA Registered: Dec 2006 posted 01-03-2016 12:42 AM                     quote: Frank Cox Jim: Why don't you sit down and watch the WHOLE MOVIE in that auditorium instead of bits and pieces? That would be very nice Frank, if running Hateful 8 wasn't taking up almost 14hrs of my day already. I wish I had an extra two hours. Don't get me wrong, I'm not complaining about the long H-F-8 shifts, I'm just saying that it currently occupies all my time. I don't even really work for this theater, but they were having a problem, and they've been very nice to me while I'm here, so I thought I'd take a little spare time to help them out and at least try to track down if it was something obvious like a blown/damaged speaker or an amp going bad, etc. I did them a big favor today by coming in extra early and lugging test equipment down here, in hopes that I'd find something "obvious". But, unfortunately, it's going to take more time than I have available right now to track down this apparently obscure problem. - - - and yes, even < I > had told the manager that the best thing for me to do would be to sit down & watch the entire movie, but he understands that I just can't work that into my schedule at the moment. There's only so many hours in a day that I can be productive, and right now my focus (no pun intended) is on running the H-F-8 shows.  |  IP: Logged George Germisashvili Film Handler Posts: 16 From: Republic of Georgia Registered: Oct 2011 posted 01-03-2016 12:41 PM                     I heard some sub distortion during show at IMAX cinema, 2 days before, the system is only 4 month, every day sound calibration status "pass OK", so idea is that Walt Disney made not only bad "Star Wars" movie, but also something wrong with sound. Once the movie will end at auditorium, the sound problem with sub will go away The better way to check- record the amp output by oscilloscope with record function or use USB oscilloscope, and after check the waveform peaks.  |  IP: Logged Jim Cassedy Phenomenal Film Handler Posts: 1661 From: San Francisco, CA Registered: Dec 2006 posted 01-03-2016 08:50 PM                     They moved Star Wars here to another auditorium. Problem solved. (sort of)  |  IP: Logged

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