Film-Tech Forum ARCHIVE: Non-Standard Practices (a.k.a. We Don't Need No Stinking X-Curve!)

This is topic Non-Standard Practices (a.k.a. We Don't Need No Stinking X-Curve!) in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=004561

Posted by Manny Knowles (Member # 1171) on 02-16-2003, 06:35 PM:

Well, I've been reading the PDF documents by John Allen (the links are posted on page 2 of the "Mic Placement" thread) and, I have to admit, I'm inspired to experiment a little.

So...

What are some of YOUR "cheats" when you EQ an auditorium?

Do you calibrate at a number other than "7" so that the movies will play at "7" when you're done? (I've done this a couple of times.)

Do you privilege certain frequencies to make dialogue stand out? (Done that, too.)

Do you have unusual microphone placement? (Not yet, but I'm willing to experiment.)

Would you use Cat. 69P to generate pink noise for EQ'ing? (Would this work?)

SPECIAL REQUEST: Let's consider anything that's non-standard to be a "cheat." One more thing: In the interest of collecting as many "confessions" as possible, maybe we ought to go easy on the smack-downs.

EXCEPTION: If something is just flat-out wrong or very strange then maybe it's in the best interest to say so and/or request clarification.

It will be understood that these are non-standard practices.

[ 02-19-2003, 08:32 PM: Message edited by: Manny Knowles ]

Posted by Rick Long (Member # 213) on 02-16-2003, 08:56 PM:

Forgive me Film-Tech for I have sinned....

Before leaving this theatre (4 hours one-way from our Toronto base), I decided to check (as is standard practice) the B-chain levels. I know for a fact that they were properly set at the time of installation, but have never understood, on subsequent checks, why they always drift from their settings. Thus, we check'em.

3:00 AM - With a house that runs from 10:00 AM till midnight, this is the only way to get any real service done.

I am the only one in the theatre.

Installing a Cat.85, and setting the fader to exactly 7, I switch on LEFT channel. I go downstairs with the Radio-Shack S.P.L. (C weighting, slow response). I read 82.5.

Instantly, I realize that this could be a never-ending trial-and-error stair run (lotta stairs too) until i reach the proper level.

Having a doctor's degree in laziness, I decide (back at the booth) to lower the monitor level with the S.P.L. meter held against the monitor speaker until i read exactly the same reading as I read in the auditorium.

Then (fortunately the processor and monitor are in the same rack), I raise the output level in the processor for a reading of 85.

Returning to the auditorium for verification: exactly 85 on the nose.

Ditto for the other channels.

I continued this proceedure for the rest of the theatres.

I re-checked in the auditorium for each channel of course.

Still involved quite a number of stairs, but cut the trial-and-error proceedure a lot.

Edited for me grammer.

Posted by Steve Kraus (Member # 476) on 02-16-2003, 10:41 PM:

Not really a cheat since you double checked it. More like a brilliant timesaver.

Posted by Christopher Seo (Member # 7) on 02-17-2003, 12:33 PM:

Manny,

I wouldn't call John Allen's methods "cheats", nor would I equate non-standard methods with cheats in general. Non-standard his procedures are, but they are neither casual shortcuts nor blindly-applied guesswork, as "cheat" might imply.

Rick,

Your "cheat" certainly is clever but I don't understand how altering the processor levels would yield the same change in SPL from the booth monitor as from the auditorium unless the reverberant characteristics were the same. Perhaps the difference is minor, but I wonder how much of the SPL of an average auditorium is due to the reverberant field. Booth monitor compression might be an issue too. Of course, as Steve said, as long as one checks it afterward it doesn't really matter.

Posted by Michael Schaffer (Member # 1204) on 02-17-2003, 08:45 PM:

You realise of course that John`s approach needs a lot of ear training and listening experience and is not an invitation for everyone to start adjusting the systems!

Posted by Paul G. Thompson (Member # 655) on 02-17-2003, 10:03 PM:

John has a trained ear. He knows exactly what he is listening for. [Smile]

Posted by Rick Long (Member # 213) on 02-17-2003, 11:30 PM:

Christopher,

You are right, of course, reverberant characteristics in the auditorium would be vastly different that those found directly in front of the monitor speaker.

However, since the reading was taken in the same place in the auditorium (I knew that, because i left my pack of smokes on the seat), reading the same channel, the relative change in volume produced the same effect in both cases. (Both agreed with the increase).

Also, I hasten to mention that each channel had to be checked in the auditorium before adjustment (of course) to find out how much of an increase (or decrease) was necessary.

I agree that this might not happen in every case, but it worked in this instance, although there were 3 cases where I did in fact, have to make extra trips to the booth for minor trimming after the monitor test. (especially when around 7 AM I realized that I had trimmed the wrong pot). [Mad]

This did enable me to set levels on a 12-plex in one night, however.

Posted by Randy Stankey (Member # 64) on 02-18-2003, 04:53 PM:

quote:
Rick Long: This did enable me to set levels on a 12-plex in one night, however.

Oh! The joys of a nice, long serial cable and a laptop computer so that one can run the cable out the booth window and sit in the back few rows of the theater while making said adjustments! [Smile]

Computerized/Digital sound processor required. A good pair of earmuffs would likely be desireable. [Big Grin]

Posted by Rick Long (Member # 213) on 02-18-2003, 09:37 PM:

I agree Randy, IF ONLY these had been other than sealed port-holes with no way of opening them, if ONLY these had been 500's or 650's instead of 65's, if ONLY we weren't so short staffed (with the lay-off of our best technician and supervisor last year) that we could only afford to have one man on the road....."the terrible IF ONLY's accumulate" - Churchill.

We screamed about the sealed port-holes. We were promised "No problem, we'll put in a 3" capped pipe between the booth and auditorium as soon as the installation is finished" We're still waiting.

Posted by Mark Gulbrandsen (Member # 72) on 02-18-2003, 09:52 PM:

Manny said "Well, I've been reading the PDF documents by John Allen (the links are posted on page 2 of the "Mic Placement" thread) and, I have to admit, I'm inspired to experiment a little."
_________________________________________________________________

Oh no....POOR MANNY! Now he's been brainwashed!!!!!!!

Of course JA assumes that none of us carry mic calibrators either.....according to his last article in B.O. but I think he'd be surprised to learn that alot more techs carry them than he thinks.....I'd also be willing to bet that if he did a study of hearing change/deterioation over a decade or so, that he'd discover that ones hearing ability is more likely the thing that IS subject to the most overall change.

Rick, All you've done is to set the output levels from the processor to the same levels...assuming that the amp level pots were all in the exact same place. Unfortunately alot of auditoriums and speaker positions are not ecxactly installed symmetrically allowing one to get away with this method. For instance, if a left chan speaker is placed closer to a side wall than the right speaker is......assuming an exit at the right of the screen, or if the room itself is not symetrical.....
Mark

Posted by Rick Long (Member # 213) on 02-19-2003, 02:21 AM:

Mark, these were read with the switch to AMPLIFIER OUT position, and were pre-and subsequently checked IN the auditorium.

Posted by Manny Knowles (Member # 1171) on 02-19-2003, 07:24 PM:

First -- I did not mean for it to seem as though I was calling John a cheat. I realize that it could be read that way. Sorry about the confusion.

On the contrary, as I mentioned -- and as Mark pointed out -- I found John's writings to be intriguing and I even tried his technique in one of my theatres today.

Here are the links that John posted in the "Mic placement" thread:

http://www.hps4000.com/pages/special/missing.pdf
http://www.hps4000.com/pages/general/the_mythical_x_curve.pdf
http://www.hps4000.com/pages/general/toss_meters.pdf

Guess what? It sounds amazing in that theatre. John says that we can't be sure what a movie is supposed to sound like, and this is true. The fact is that it sounds better in that theatre than it did last week -- or yesterday, for that matter.

For the record, that system was EQ'd last week using the X curve and the official procedure. John's method took less time to carry out and it resulted in fewer EQ bands being altered. The same movie (CHICAGO) is showing in that room and it sounds much, much better today than it did yesterday. I can hear more bass than before and I can hear that the surrounds are getting in on the action without anything seeming "too present." Vocals are coming through nice and strong -- and with great clarity. Overall, the room has really come to life. The film is playing at 7 (where it was indeed calibrated). It's plenty loud without seeming so.

So...Thank you, John! I'm converted.

[ 02-19-2003, 08:31 PM: Message edited by: Manny Knowles ]

Posted by Gordon McLeod (Member # 33) on 02-19-2003, 09:14 PM:

Sorry definitley not converted also I to carry a calibrator for my spl meter and one for the RTA mics

Posted by Rick Long (Member # 213) on 02-19-2003, 09:54 PM:

Thank you for the links, Manny. They do indeed make for interesting reading.

Posted by Manny Knowles (Member # 1171) on 02-19-2003, 10:12 PM:

You know...it's fine if the standard way works for you. Hey, by all means, if it ain't broke, don't fix it.

But the standard way of doing a B-Chain just wasn't working out for me. It's not rocket science and I'm certainly not an idiot but it just didn't provide me with good results -- I never liked what I heard with program material and I have no way of knowing what any of these movies is really supposed to sound like anyway. In the end, it came down to a balancing act of my trust in the system and trusting my own ear. In the end, my ear kept winning. So, I had to determine that the established system could only get me so far...and then, I'd be on my own.

This other way just works better for me.

Posted by Michael Schaffer (Member # 1204) on 02-20-2003, 06:34 AM:

Maybe "converted" sounds a bit strong, it is not a religious issue [Smile]

It should be noted that the methods described in the texts are not saying that measurements should be discarded, but that alternative measuring methods are more effective.
The human hearing indeed changes as we age, but it can "calibrated" too by listening attentively to high quality musical material. Some musicians are very old and their hearing has "deteriorated" but they can still judge tone and sound quality very well because they know how to hear analytically.
The human hearing is very fascinating because it is very subjective but at the same time an enormously powerful measuring instrument if trained properly.
For instance, I can always tell if I am listening to a recording of, say the Berlin or the Vienna or the Los Angeles Philharmonic regardless of the the program they are playing, the playback equipment or the room I am listening in because musical tone has a very distinct shape which you can learn to recognise.