This is topic Dolby A at fader 7 in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Michael Brown (Member # 890) on 05-24-2002, 06:56 AM:
Is is totally accurate to say the the fader must be at 7 completely all of the time (just a Dolby A analog auditorium).No matter what film. 7
Posted by Brad Haven (Member # 954) on 05-24-2002, 07:20 AM:
No!.
We have our dolby SR systems aligned by a good tech, cinema one settles at around 6 and cinema 2 (smaller) settles at 4. We also set our trailers at individual levels , even film ads, if dramatically diffrent, which does occur!.
Each film should be set for it's own volume, as i find that most films have very varying levels. I used to work with dolby A and we found the same result. Not having worked with digital sound (at work that is)i cant comment on those set ups.
Posted by Michael Brown (Member # 890) on 05-24-2002, 07:28 AM:
I tend to find that I need to run the set up at at least 7. The average setting is 7 and a half. I supposed it depends on the film.
I'm sure that the system has been aligned properly. And the Dolby Level is definately correct.
Posted by Brad Haven (Member # 954) on 05-24-2002, 07:49 AM:
i find that it really depends on many factors ,amps ,speakers, acoustics e.t.c...
our other location (SR and dolby A) set theres at around 6 and 7.
Posted by Greg Mueller (Member # 17) on 05-24-2002, 09:12 AM:
On my system (CP65) I have to run "A" and Mono at 7, but SR and DTS at 5. No doubt I'm doing something wrong------------------
Greg Mueller
Amateur Astronomer, Machinist, Filmnut
http://www.muellersatomics.com/
Posted by Leo Enticknap (Member # 534) on 05-24-2002, 09:27 AM:
In my cinema days I distinctly remember two venues at which A-type was usually played at half a notch to a notch higher than any other format. The only explanation for this I can think of is that within a cinema processor, the preamp gain for A-type is separate from that of other formats.
Posted by Frank Angel (Member # 248) on 05-24-2002, 09:43 AM:
Guys, there is a reason why Ray Dolby put a volume level control on the front of the processor - volume is not absolute. As mentioned, many factors in the theatre "B-chain" acoustical environment will impact the apparant sound level in the room. Everything from temperature and humidity to the number of bodies in the room will change have an effect, to say nothing of the type of sound mix as well as the age of the audience. Guaranteed a young crowd of rock and rollers watching ROCKY HORROR PICTURE SHOW will think a level 7 is much to low....a Sunday matinee of seniors watching ON GOLDEN POND will think a 7 is too loud. Audience comfort will not always pin out a Dolby reference. If there were such thing as an "absolute correctlevel," then the level controls on the output card would be all you would need -- why put a manual level on the front panel at all? In a well calibrated system, yes Dolby 7 is the mean reference level -- but you use that as the STARTING point; you use your ears and the audience as the ultimate decision-making reference instrument.
Frank
Posted by Paul G. Thompson (Member # 655) on 05-24-2002, 02:21 PM:
No!I heard somewhere that when the system is calibrated with the Pink Noise Generator, an error is "built in" with the generator. I have heard that at least a 100mv error is introduced. If calibrated with fader set at 7, the actual level of the fader will run around 6 or so.....Maybe Steve Guttag can shed some more light on this.
I have also heard that it is a good idea to calibrate Dolby Tone levels with the system punched up on MONO. I have heard several instances where the SRA adapter will perform much better without excessive "pumping".
Posted by Antonio Marcheselli (Member # 373) on 05-24-2002, 02:35 PM:
Frank,Yes your're right. On a well calibrated system, you usually play around 7 (6,6.5,7) depending of your taste, your auditorium, your speakers, the mixing.....
My system was intentionally calibrated at 6.3 (for some valid reasons). I remember that I projected a movie at 5.0 but was just a movie, the other ones stays at 6.0-6.5 range. SR movies usually stays at 7.0.
But, I believe, if you usually have to project at 4... Well, something is wrong.
Bye
Antonio
Posted by Gordon McLeod (Member # 33) on 05-24-2002, 08:56 PM:
This topic has been hashed over and over again
If the system is set up properly with 85bcs slow from the generator card and the ISO eq curve has been followed then the level matchs the mixing stage. To the average listener it is to high so typically most theatres run between 5 and 5.5
If you play to the standard John Q public and the fader is at 7 or up without complaints on most hollywood movies then something is wrong.
Posted by Brad Miller (Member # 2) on 05-24-2002, 09:02 PM:
And I'll argue that as I always do. I run films all the time at 6-7 (but mostly at 7) with zero complaints. Everything is set up to spec. I find that theaters with bad acoustics and/or "not exactly great" speakers and most frequently an over-EQ'd B-chain have to run more at 5. Also, theaters where the tech calibrated the system and said "there you go, that's as perfect as it will ever be" end up playing at 5. The HF rolloff really needs to be double checked by ear before packing up and leaving the job, for no two auditoriums are alike. I believe it was Ioan Allen who has even stated this (as well as other forum members, some of which are THX certified but do not post on this subject because apparently this is a taboo subject). I have EQ'd my share of "crappy auditoriums" and end up leaving the fader at 5 myself. However I continually find that a well designed acoustical environment, good speakers with proper positioning and a good B-chain generally runs at 7.Of course the bottom line to the question being asked at the start of this thread is to play it at whatever setting sounds best and does not bring about audience complaints. Treat the 7 as a reference starting point in determining the fader setting is what I tell most people. At least that advice I believe 99% of everyone will agree with. 
Posted by Steve Kraus (Member # 476) on 05-25-2002, 02:06 AM:
Leo: A Dolby print would need to run at a higher fader settings on a mono system because the track is recorded at a lower level than a typical mono track. They're taking the improvement in noise floor that Dolby noise reduction creates and trading some of it for more headroom. In other words, lowering the overall level (and compensating with more gain in the processor) allows the peaks...an explosion, say, to be that much higher without clipping than they otherwise could. Dolby A optical stereo print runs at a lower level than mono and an SR print runs lower than Type A. Both would need to run at higher fader levels on a mono system. If you're talking about a stereo system SR will need to have the fader turned up if it was setup for SR by simply plugging in cards in place of the A cards.
Posted by Gordon McLeod (Member # 33) on 05-25-2002, 09:39 AM:
Well I as usuall disagree and a case in point
I service a fair number of dubbing and mixing stages and we took a print and its final mix to a theatre for a private and a public select screening
We Eq'd the room to speak ran the print it sounded exactly like what I and the crew heard on the dubbing theatre. THe mixers were also happy
The fader was at 7
When the public was admitted the fader was being constantly being lowered because of complaints until it was back at 5.5
The sound dept. then walked out as they felt there mix was ruined
That is why we have a standard. The fader setting is adjustable the rest should match the spec. Also the rolloff is specified based on room volume
Posted by Brad Miller (Member # 2) on 05-25-2002, 10:28 AM:
It wasn't a "Mummy" movie, was it? Those mixes sound best at 0. 
Well as usual we will disagree on this one, but it certainly is fun to debate it. In the meantime I will continue to run the faders at or near 7 without a complaint and won't even bother telling you that at Northpark we generally ran our movies between 7.5 to 9 without complaint! (For reference I do specifically remember we ran Titanic in 70mm DTS at 8.75 from the first day to the last.) Anyone who ever patronized that theater can vouch that the level was not too loud and the experience was phenomenal. 
Anyone on the forums been to the Northpark in Dallas? Anyone see Titanic there?
Posted by Michael Brown (Member # 890) on 05-25-2002, 10:44 AM:
So if i find that 7 and a half is my average level. I'm not commiting a mortal sin?
Posted by Brad Miller (Member # 2) on 05-25-2002, 11:04 AM:
Michael, you will surely burn for all eternity for running at that setting! (just kidding of course)Seriously, just play it at whatever provides the best presentation and makes the customers happy. The customers don't give a damn about what number your fader is set on, so long as their show is as good as it can be.
Posted by Michael Brown (Member # 890) on 05-25-2002, 01:41 PM:
How much would an increase of half a notch actually have anyway?
Posted by Manny Knowles (Member # 1171) on 05-25-2002, 02:00 PM:
For years, I have been hearing that each number is 3dB SPL up or down, but I've also heard arguments going against that.------------------
~Manny.
Now...where was I ?
Leonard Shelby, MEMENTO.
Posted by Craig Hanham (Member # 1010) on 05-27-2002, 08:57 PM:
My 2 cents worth.
When I had my plant upgraded and a Dolby CP65 installed the tech. set reference at 7.
When playing Holywood releases its all good.
However 95% of the Bollywood releases I show 7 is way too loud and I run at 5 to 6.5 depending on print. Then again maybe giving the punters earbleeds is the thing with Indian sound mixers
Posted by Jason Burroughs (Member # 68) on 05-27-2002, 10:09 PM:
I saw Titanic at GCC Northpark I-II when it was in 1, the sound and picture were fantastic. Great dynamic range, dialogue was crisp and clear, and the sound level in general was not over bearing.BTW, the 70MM print they had looked great.
Posted by Paul G. Thompson (Member # 655) on 05-27-2002, 10:18 PM:
There was a "Dirty Harry" movie with Clint Eastwood about 18 years ago, but I forgot the name of the movie. However, it featured a scene of a dog passing gas. Every time I ran that movie, I advanced the fader to 10 for that passing of gas sequence. It seemed to add something to the movie, as the audience roared in laughter. The louder it was, the harder and longer the audience laughed.
Showmanship, I guess...