Glad you got ‘intelligibility’ on speed type…the last use was just as brilliant as the first. 

So many issues. I’m starting to like that idea of the cinema giving me a wireless 7.1 headphone mix that I receive in my personal headset, with an app that allows me to set the various levels and positions.

Good point about dubbed dialog…they are made by and mixed by people who haven’t been sitting with the dialog for the year of production - they are hired for their professionalism at one task, and the director isn’t sitting over their shoulder, but has long gone onto some other production. Having lived in France for over a decade and doing many installs in Italy where they both do an absolutely incredible job of dubbing, I can appreciate your point. 

On the other end of the spectrum, I am just now writing an article about the new QSC Cinema Certification program. As you can imagine, I am all in favor…thrilled about, in fact…every attempt to increase Quality Assurance for the customer. 

Unfortunately, QSC grabbed NC-30 as a number to meet for a noise floor, while SMPTE RP 141:2005 calls for a 1st run cinema auditorium to have an NC value of 25, allowing “Sub-runs” NC-30. In the digital world, there are no sub-runs. 

The problem with NC ratings used to be that they were concerned with the vocal area and didn’t go below 125 Hz – RP 141 took care of that by extrapolation, but if someone just quickly looked at the NC numbers they wouldn’t know that. ANSI S12.2-2008 adapted the NC curves to go lower than the 125 Hz. But still, NC-30 allows rumbles at 16 Hz and 31.5 Hz at 81 dB and 68 dB and a 60 cycle hum at 57 dB. Threshold of hearing at 63 Hz is 40 dB. I know that I have chased down 60 cycle hum at less. 

QSC is also using a through-the-wall rating that is STC 60-65…STC 65 is a great number for the vocal range, but STC also doesn’t take measurements lower than 125 Hz. But there I was last week trying to correlate the sound I was hearing several times while watching Fantastic Beast – which surprisingly had several quiet parts – except in these quiet parts there are these rumbles and I’m thinking there is trouble brewing outside the scene we’re watching…except it is noise constantly coming from the auditoriums to the left and right. …like, constantly. 

And, of course, the QSC specs are only using US measurements, not ISO 16283 Sound Reduction Index or the like. I mean, I wish them luck but they seem to have decided to go for the least common denominator.

Anyway, all you wrote is correct and there is much more, right? It is like those wheels that people have drawn every key of the Circle of Fifths upon, with pins so you can stretch cords around different keys a song is in. There are all these interconnecting parts to what we are listening too. Great to be part of the discussion.

Finally, thinking about you sitting there modulating the sounds and getting to a real soft part: there is an admonition in the Annex of SMTPE RP 141:2005 
A.3 Too little noise in a theater or review room may be a problem as well as too much. With too much noise, detail is obscured and, ultimately, intelligibility suffers. With too little noise, intermittent intrusive noise may become audible and annoying; therefore, it is advisable to use reasonable background noise levels to mask intrusive noise sources

Keep having fun and good luck to us all.  C J F
 

On Nov 29, 2018, at 4:56 PM, Carsten Kurz via DCPomatic <dcpomatic@carlh.net> wrote:


Am 28.11.2018 um 18:54 schrieb cjflynn@digitaltesttools.com:


Indeed, it is going to be a learning process, a political process, a technical process, then repeat repeat repeat.

Myself, I am finding more and more that because the movie has been turned down that I can’t understand the dialog…a counter-intuitive effect of the perception problems that our hearing systems generate when the  Equal Loudness Curves are accommodated for.


Okay, you called for it...

There really are A LOT of issues concerned here. A number like 5.5 or 7 only serves as an abstract symbol.


Just ONE of those many other issues is that modern production techniques make it possible to create audio content with a much higher dynamic range, tailored to the preferences of highly skilled, 'overmotivated' (and I do not even mean that in a negative way) professional audio engineers/film sound mixers.
Until not too recently, they were limited by equipment and pre-digital/pre-LPCM standards. Dolby A/SR/SRD was the limit, as well as analog sound recording equipment, mixing methods, etc. Today, they have everything under their hands and facing their ears what they ever dreamed of. Digital Sound FX can create signals with ANY imaginable spectrum, dynamics, level. No distortion added by mics, amps, converters, tape... DC offset anyone?

From a very recent impression, I just sat through 'The Children Act' (twice). During both presentations, I found myself adjusting it from our standard 5.5 to 6.5 during the first half hour (I can do that from my smartphone while sitting in the auditorium, hiding it from other patrons below my seat).
There is e.g. one shot where Emma Thompson is staring out a closed window, watching her husband packing up and leaving with his car. The sound level of this car is (realistically) very very low. Over a period of maybe 10s, there is no other sound at all (except maybe for some even more subtle ambient sound), and the image shows just the car vanishing.
At 5.5, it was below common perception threshold. Yet they bothered putting it in at that low level. And no, this was not a mistake on their side, they wanted it like this, the mix is excellent all over (I probably could have given it a 7 just as well). Now, there are probably more important pieces of audio in a dramatic movie than the sound of a vanishing car through a window. But that is the mesmerising creative level sound recordists, foley artists, and the like are working on nowadays. These soundtracks are not limited by technology or ambition or talent, only by the time these people are granted to finish their work prior to release. And by an aging audience willing to accept it.

I very often do these adjustments during presentation, because I watch many of the DCPs we show. Most of the time, I dial slightly higher than 5.5, like 5.8 or 6. There are mixes that simply need to be leveled higher, there are some that really shine leveled higher. Some very few (maybe one each year) need to be leveled lower than 5.5, because they yell at the audience, and they do not contain ANY subtlety.

Yes, I do this to my personal liking, and I hope my hearing apparatus is not too far off from our audiences. So far, few (if none) complaints.

Admittedly, we do play a lot of dubbed arthouse titles. You may know that the germans prefer to watch/hear dubbed movies (that changes only slowly). One key aspect of dubbed movies here is that, because so many movies are dubbed in germany since nearly a century, our dubbing studios and dubbing actors work on a very sophisticated level (means, they also have plenty of work for tv, cinema and streaming services). There are always good and bad examples, but in general, dubbing is not done cheaply in germany, trust me.

Both artists and recording mixers strive to achieve the best speech/dialog intelligibility, and the major difference to location sound is close/proximity miking and booths.
They can later add room, reverb, reflections, EQ, whatever is needed to match the scene, but they do all that with priority on intelligibility. If the sound recordist hears the slightest mumbling - another take. So, I think, as far as speech intelligibility is concerned around germany (and similar countries in that respect), slightly lower levels do not immediately hurt that intention of dialog intelligibility (wait, I need to put that word on a shortcut-key...done ).
BUT - it still hurts emotional vocal expression. The breathing and trembling is lost. Same as if you would be watching the screen from the very last back row, losing facial expression in all but close ups (if the actor is able to show such).

Switch to movies produced locally, usually with location sound, and dialog intelligibility (hah!) suffers a lot.
You may remember that report/survey on sound recording mixers monitoring habits I linked to on the ISDCF mailing list a while ago (I think it was also mentioned in a meeting note). I guess many smaller budget, but probably also some higher budget films, are now mixed on smaller, 'close to' nearfield monitors. Speech intelligibility (...) is SOO different between a small, well controlled nearfield studio setup and a typical large cinema auditorium. Even if they QC the mix/movie later in a decent auditorium - most of the talent there already know all the dialog lines from hearing them over and over and following the sheets during production. They are probably still concerned about various aspects of the mix - but I think they will/can no longer concentrate on speech intelligibility with priority, except maybe for some very important parts that have been messed with too much.

Okay, I said 'ONE of those many issues', let's finish here for now...

- Carsten


















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