This is topic Loud projection booths could damage hearing in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.


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Posted by Brad Miller (Member # 2) on 02-25-2003, 03:55 PM:
 
From the discussion on loud movies here...has anyone building theaters ever put any thought into this scenario?

*Projection room at a small multiplex with no more than 2 projectors close to each other (separate booths).
*All Strong equipment.
*No carpet, just a raw cement slab.
*No ceiling tile, just hard surfaces overhead.
*Projectionists typical shift confined to the booth 8-12 hours.

Anyone want to guess just how LOUD it is in there??? Please make your guesses in C/Slow db.
 

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Posted by Adam Martin (Member # 641) on 02-25-2003, 04:05 PM:
 
88db
 

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Posted by John Pytlak (Member # 331) on 02-25-2003, 04:09 PM:
 
Where is the measurement being made? How close to the projector? Are the booth monitors turned up?
 

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Posted by Joe Beres (Member # 678) on 02-25-2003, 04:20 PM:
 
Which lamphouse? Where is the exhaust fan?
 

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Posted by Brad Miller (Member # 2) on 02-25-2003, 04:21 PM:
 
Cenury projector
Highlight II consoles
Strong platter (model really doesn't matter here)

Booth monitors are all off.

Exhaust vents outside, but there is no air conditioning. (Yes this is a theater in Texas that was built with no air conditioning in the booth!)

Measurement is made halfway between the projectors. In some rooms this could be 15 feet away, others only a few feet away. There are 2 projectors per room. (Just think how bad this would be if all were in one common booth!)
 

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Posted by Paul G. Thompson (Member # 655) on 02-25-2003, 04:57 PM:
 
Mine is carpeted, with drywall ceilings and floors. Tri-Plex. About 75db.

I once visited a 14-plex up in this area. Cineplex. Had an open ceiling, right up to the roof and its trusses. Concrete floor, and standard drywall. Simplex 35's, Strong lamps and platters.

Noise level was so high, I would presume, from my experience, that the average person would not want to spend more than 4 hours at a time in that booth. That place was LOUD!
 

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Posted by Joe Redifer (Member # 3) on 02-25-2003, 05:21 PM:
 
Hmmmm... class action lawsuit!
 

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Posted by Daryl C. W. O'Shea (Member # 1303) on 02-25-2003, 05:22 PM:
 
My 7-plex single booth with Alpha 3's (which don't really make noise), V5's, tile ceiling, tiled floor, ply-wood (on top of a few layers of dry-wall) walls and killer air-conditioning runs at about 90+ dB.

After spending 14 hours or so in the booth, the eerie silence and presence of light scares me when I exit the booth and enter the lobby.

BTW, you can yell from one end of this straight stretch booth (while everything is running) and not be heard at the other end.
 

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Posted by Brad Miller (Member # 2) on 02-25-2003, 06:26 PM:
 
It's good to see people are finally "hearing" me when I complain about booths that do not have carpet and ceiling tiles. Honestly, I don't know how some people can work in that amount of noise. While I don't have any hard proof, I just know it is killing the projectionist's hearing.

Not too long ago I worked a noisy booth like this for a couple of months to get things fixed up for them. One day I left there and headed straight to another theater to service them and I had forgotten what a difference it made. I didn't even realize the film was running at first. They had carpet and ceiling tile. Their ought to be a law against these "unfinished" booths.

Anyone out there reading this that has the final say-so on new construction, if you choose to go the cheap route and not put in a drop ceiling and carpet, YOU SUCK! May someone sue your ass off one day for it.
 

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Posted by Daryl C. W. O'Shea (Member # 1303) on 02-25-2003, 06:30 PM:
 
That's the sucky thing about the Galaxy booths, they are actually nice. Nice blue/white speckled tile floor, nice black tile (drop) ceiling, and actually nice dark blue painted walls. Nice and dark too (I actually like that). So it's really a finished booth... just no thought into how loud it's going to be with the materials used.

It's easy to keep clean... just loud.
 

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Posted by Brad Miller (Member # 2) on 02-25-2003, 06:31 PM:
 
When I say "finished" booth, floor tile does NOT count. Also, an acoustical drop ceiling is mandatory, as is carpet. It is amazing how many people just don't give a damn about their employee's work environment. Not only does this affect the employees running the projectors, but whatever sound leakage there is via the port windows will just be magnified if the booth is loud to being with. Of course, the smaller the booth, the worse this is too. Duh!

When I was in college I ran a single screen booth that was about 15x10 feet. It was so noisy in there the projectionists just couldn't stay in the booth, so we would gauge how much time was left on the reel and keep an eye on our watch and sit in the lobby. A few minutes before the changeover we would enter, do the switch and rethread the next machine then get out of there again. It was just too loud. No reels were rewound until the show was over and the machines were off. We finally got management to let us purchase some 1x1 foot self-adhesive carpet squares and from then on we could stay in the booth.
 

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Posted by Gordon McLeod (Member # 33) on 02-25-2003, 07:10 PM:
 
Carpet is a static nightmare and is something I don't particularly like in booths
Accoustic wall tiles are by far a better solution
 

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Posted by Paul G. Thompson (Member # 655) on 02-25-2003, 07:26 PM:
 
I never had a static problem with carpets in the booths I worked in, not out here, anyway. Maybe they were treated with anti-static chemicals...I don't know.
 

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Posted by Mark Gulbrandsen (Member # 72) on 02-25-2003, 07:40 PM:
 
Paul,
The main problem with carpet is that it holds alot of dirt big time. Every time you walk across it the dust is sent airborn and lands on the films you have around it. Carpeting gets a no vote from me....
Mark
 

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Posted by Joe Redifer (Member # 3) on 02-25-2003, 07:42 PM:
 
I never had static problems in the carpeted booths I have worked in, nothing "serious" anyway. And that was BEFORE Filmguard! At Greenwood the floor was carpeted and we had lots of traffic from people walking all over the place, and this was just after polyester stock was introduced. Never any big problems caused by it. Must be a Canada thing. Filmguard would pretty much alleviate any concerns I had about that anyway. Acoustic wall coverings would be good IN ADDITION to carpet! Also never saw what I would consider a really "dirty" print at the Greenwood. They have invented vaccuums as well. They work great!

About the 1' x 1' square self adhesive carpet... how much does that stuff cost? I'd like to do that for my booth at the very least (it is tile but has a drop ceiling... and cinder block walls). Would it be cheaper just to have carpet professionally installed everywhere? I hope so, 'cause it would take FOREVER to cover my booth with those little squares. My booth is a little over 125 feet long and 12 feet wide.
 

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Posted by Brad Miller (Member # 2) on 02-25-2003, 09:13 PM:
 
We opted for the self-adhesive carpet squares because the booth was so small. In your instance I'll bet it would be cheaper to have a company come in and install carpet professionally.

Gordon, never, never, NEVER has carpet been an issue with static or dirt. Not even way back before I started using FilmGuard. I also know lots of theaters that don't have any form of film cleaning with carpet that do not have problems. I don't doubt that it affects it a little bit (maybe moreso in Canada), but you're taking it over the top. It doesn't make a noticeable difference in static or dirt. Besides, professional operators will not let the leader run across the floor anyway and I consider a soft carpet better for the film than a cement or tile floor. In the event something happened and a chunk of film got on the floor (from a toss or failed takeup), the carpet doesn't scratch the hell out of the film like a non-carpeted floor does.
 

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Posted by Gordon McLeod (Member # 33) on 02-25-2003, 09:16 PM:
 
failed takeup ?
tossed prints well that is one of those inferior platter isues

Accoustic Wall tiles will reduce noise levels far better in the mid and high bands than carpet ever will
 

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Posted by Brad Miller (Member # 2) on 02-25-2003, 09:18 PM:
 
Don't tell me you've never had a takeup belt break on a reel to reel machine and the operator not noticed. (I have no idea WHY they did not notice, but it happens.) I've seen it happen and in the carpeted booth there was no noticeable film damage once it was reverse-spooled back up. When it has happened on tile floor booths, the film was badly scratched. Both were EQUALLY dirty.

Tossed prints comes from techs who don't know how to set up a platter properly, or from "junk" platter designs.
 

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Posted by Paul G. Thompson (Member # 655) on 02-25-2003, 09:34 PM:
 
Joe, I have my people (including myself) use that wonderful invention you mentioned.
 

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Posted by Bill Enos (Member # 440) on 02-25-2003, 11:53 PM:
 
For a cheap and very effective anti static spray, mix 2 oz. liquid fabric softener with a quart of water, mist carpet lightly when leaving for the night. Treatment lasts for about 2 weeks. Pick your scent. The smell is pretty much gone the next morning.
 

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Posted by Chris Wootten (Member # 283) on 02-26-2003, 06:36 AM:
 
A booth that I worked in a few years back (Victoria) had polished floor boards, acres of GLASS windows and fibro walls. Cinemecanica Vic 8's twins. I eventually convinced the bosses to get carpet for the floor ( a special plastic/rubber compound that is static free) and EAZY to clean, and all the walls and windows got the "tile " treatment. I could actually talk to my trainees without yelling...it was bliss. My own hearing has been damaged and can never be fixed now, but I am also and OLD fa_t so that would not help either. HA!
 

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Posted by John Pytlak (Member # 331) on 02-26-2003, 07:42 AM:
 
Although some prefer bare floors because they can be wet-mopped to keep them clean, leg comfort and lack of noise abatement are issues. And many bare cement floors are not properly sealed, which can make them an issue for abrasive debris.

If carpeting is used, is should be a short nap commercial carpet that is easy to vacuum and shampoo, and not likely to shed fibers. Antistatic treatments are readily available and easy to apply during shampooing. Synthetic fiber "Indoor-outdoor" carpets are often a good choice, and resist staining well. When vacuuming, use a central vacuum system or a vacuum equipped with true HEPA filtration, so as not to put tiny particles back into the air.
 

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Posted by Scott Norwood (Member # 30) on 02-26-2003, 08:32 AM:
 
Joe--I thought that you used PTR rollers to clean your booth carpet? Or was that before you got those Strong platters with vacuum cleaner motors?
 

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Posted by Randy Stankey (Member # 64) on 02-26-2003, 09:47 AM:
 
Most Cinemark booths I have worked in average 70 to 80 dB, depending on where the measurement is taken.

If standing right NEXT to the projector the level is as high as 90 dB... even higher with the booth monitor turned on.

If standing in the hallway NEAR a projector but not right next to it I have seen it as high as 75 to 80 dB. (Monitors off.)

If standing in the middle of the room, not near a projector (Say, at the work bench) it is about 70 to 75 dB.

I have done this at more than one booth and the measurements were taken with "C" weighting and "Slow" sampling. This is the average I have gotten over several (about 10) booths. Some booths were a bit higher and some were a bit lower.

If I remember right, the maximum continuous noise level allowed by OSHA is 85 dB for up to 8 hours exposure. If the levels go above that (or for longer than 8 hours) the employer must provide abatement measures... including sound-proofing the room (carpet, acousic tile, etc.) and all the way up to providing hearing protection for the employees. The way I remember, this works on a "sliding scale". Employees can be exposed to louder noise levels IF they are not exposed for long periods of time. For instance, 90 dB is permissible if the time of exposure is no more than 4-6 hours... etc, etc... I don't remember the exact number but there is a maximum noise level beyond which nobody is to be exposed for ANY length of time unless hearing protection is provided. I'm going to pull a number out of my ass and say the maximum is 110 dB.

None of the Cinemark booths I have worked in were loud enough to require noise abatement, although some have been close. I can guarantee you, that in the years I have worked around machines (of all types), I have experienced noticible hearing loss and even some tinnitis. I would not fault ANYBODY who wanted to wear ear plugs, muffs or better still, electronic noise-cancelling headphones.

Aside from hearing loss, exposure to continuous noise can have psycohological effects, including irritability, loss of sleep, lack of concentration, nervousness and even (in severe cases) mental breakdown.

Personally, when I was working in the booth day-to-day I would take as much time as I could to "get away from machines" in my off hours. Living in the country, it was easy. Sitting outside in the back yard, listening to the crickets and the coyotes and all the other critters sort of had a cancelling effect on all the machine noise I absorbed all day long.

If you want to hear about REALLY FREAKY noises, check out this site on the Taos Hum!
 

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Posted by Daniel Burns (Member # 1549) on 02-26-2003, 10:50 AM:
 
The one carpeted booth I worked in was full of static. We have very few static problems in our "unfinished booths". I'm not sure if AMC has anymore carpeted booths around here.
 

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Posted by Peter Hall (Member # 695) on 02-26-2003, 11:04 AM:
 
We stuck to vinyl for years, however with the demise of projectionist rest rooms started to look at how we could make the booth a more comfortable working environment. Carpeting and good air cond were no 1 - since then we've humidity controlled the environment and at the same time used (effectively) PET based carpet and have not had a problem
 

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Posted by John Pytlak (Member # 331) on 02-26-2003, 11:16 AM:
 

quote:

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The one carpeted booth I worked in was full of static. We have very few static problems in our "unfinished booths". I'm not sure if AMC has anymore carpeted booths around here.

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Again, conductive antistatic treatments are effective and can be applied during shampooing. Conductive carpeting is also available:

http://www.aclstaticide.com/01/index.html

http://ultrastat2000.com/static_control_carpet_ultratough.html

http://www.anti-staticmat.com/ConductiveCarpeting.htm

http://www.esdjournal.com/techpapr/sfowler/ccenters.htm

http://www.usacitylink.com/citylink/afshome/top/carpet/manu.html
 

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Posted by Paul G. Thompson (Member # 655) on 02-26-2003, 12:00 PM:
 
John, its a trade-off. While in the navy, I had my share of brow and quarter deck watches, and I can tell you that standing on the steel decks in an area where there is not much room to walk around, those steel decks really do a "number" to the knees and hips.

Even today, if I stand around and shift my weight a little, a hip or knee will just "give way" on me, and if I didn't react fast enough, I would probably land on my ass.
 

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Posted by John Pytlak (Member # 331) on 02-26-2003, 12:09 PM:
 
Another problem with smooth floors is that they can be slippery when wet or oily.
 

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Posted by Joe Redifer (Member # 3) on 02-26-2003, 02:16 PM:
 
See, Gordon?... even the Kodak guy recommends carpet (although indirectly)! He's all about film done right. And so am I. I looooove carpet. But hell I'll take acoustical wall tiles in addition as well.

70's green shag carpet would be the best.
 

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Posted by David Stambaugh (Member # 1102) on 02-26-2003, 02:54 PM:
 
Don't forget about all the extra labor raking it. We had green shag carpet in our house in the 70s and my mom made us rake it.
 

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Posted by Gracia L. Babbidge (Member # 582) on 02-26-2003, 03:44 PM:
 
If wearing earplugs didn't seriously annoy the out of me, I'd wear them in my booth a lot more than I do.

If I remember correctly, the ambient noise level in my work environment (with 8 Christies & 2 Century JJs all running) is up around 76dB or so. That's loud enough to cause permanent damage with repeated, prolonged exposure.

Of all the things that I feel my booth lacks, a dropped ceiling has got to be what I would most like to see installed. I know that it would help a hell of a lot with the effeciency of the HVAC system! So much dead space overhead...
After that ... I'd want running water before a carpet! It kinda blows to have to fill three humidifiers (six gallon capacity each), by lugging buckets around! Gotta love the static-prone winter weather up here!
...Of course, the hose long enough to reach the top of the stairs does help, but still...
 

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Posted by Randy Stankey (Member # 64) on 02-26-2003, 03:55 PM:
 
Although the US Government rules state noise levels of 80-85 dB before requiring noise abatement, I agree with you that lower levels can and probably do cause hearing damage, especially when the noise carries on for long periods of time.

Electronic noise-cancelling headphones are really neat. For continuous "droning" noises like lawnmower engines, airplane propellers and machine noises they do work pretty well.

If you've never seen them, they look like a WalkMan headset but the "radio" part has a microphone and some funky electronic gizmo inside. It listens to the noise around you, inverts the phase and emits it through the headphones. The "negative noise" cancels out the "positive noise" leaving your ears in relative quiet.

Some models come built-in to industrial style earmuffs like construction workers wear. Other times they look like a WalkMan. Some of them even have the ability to plug a WalkMan or similar device into them and they mix the noise cancelling effect with music.

As I remember, I have seen some projectionists who work in "fishbowl" style OmniMax booths wearing them. I would imagine the noise level in there is really bad, thus requiring their use.

I tried a pair of them out on the shooting range. They work pretty well for "acute" noises like gunshots but they work best at long, droning noises like I said above.

Even if you don't end up getting some, you ought to at least check them out. They are pretty neat-o.
 

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Posted by John Pytlak (Member # 331) on 02-26-2003, 09:35 PM:
 
Whether it's carpet or bare floor, the important thing is to keep it clean! Vacuum and damp mop floors frequently. Vacuum and shampoo carpeting. Use a central vacuum system or one with a true HEPA filter.
 

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Posted by Steve Kraus (Member # 476) on 02-27-2003, 07:38 AM:
 
This is a topic of interest as I stay in close proximity to the machines. I have often considered adding some sound deadening to some of the wall surfaces but the Sonex type foam (one presumes it's fire retardant) I would reject because it would act as a huge dust collector. I'm thinking of nicely faced compressed fiberglass panels. But I also thought about a DIY solution, boxing in an area with 1x2's or 1x3's and filling it with fiberglass if I can think of a way to face it that looks nice.
 

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Posted by Larry Zuverink (Member # 1483) on 02-27-2003, 08:11 AM:
 
I hate carpet in the booth. We always had dust problems with carpet no matter how often it was cleaned. I agree that the booth is usually the first place money is cut but its a simple thing. If the booth loud, where ear plugs. Millions of people a day work at jobs that require them. The manager at any theatre that has a loud booth would be stupid not to require them.
 

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Posted by John Pytlak (Member # 331) on 02-27-2003, 09:27 AM:
 

quote:

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We always had dust problems with carpet no matter how often it was cleaned.

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quote:

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machines (of all types), I have experienced noticible hearing loss and even some tinnitis. I would not fault ANYBODY who wanted to wear ear plugs, muffs or better still, electronic noise-cancelling headphones.

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quote:

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Should I be concerned if it comes more often or get louder?

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I'm tempted to try a humidifier in the booth during the winter. Are there any reasons that would be a bad idea?

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quote:

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I'm thinking of nicely faced compressed fiberglass panels.

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That stuff works pretty good Steve. We've used it in some larger recording studios where sonex foam wouldn't work much better due to the large space. The nice thing about fiberglass panels is that you can paint them.
 

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Posted by Rick Stowell (Member # 1624) on 02-27-2003, 05:57 PM:
 
New member - great site! Our booth is approx. 15' x 100'. Vinyl tile floors, sheetrock walls, and METAL ceilings about 7' high! Remodeled a building, no theater experience, and these were the recommendations! I do care about the employees, and am ordering carpeting tomorrow, but I'm lost on what I can do with the ceilings being so low. By the way, we had static problems in MN, and installed a humidifier with a direct water line. It's helped some.
 

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Posted by Daryl C. W. O'Shea (Member # 1303) on 02-27-2003, 05:59 PM:
 
Attach a drop ceiling to the metal ceiling. It doesn't have to be that much lower. Only a few inches -- just enough to get the tiles in without breaking them.

The best tiles to use would be the sound absorbant ones. They're about an inch and a half thick and have insulation on the back (top) of them. Avoid using 'solid' tiles. Even the thin 'flexible' tiles would be better than 'solid' ones.
 

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Posted by Michael Rourke (Member # 1142) on 02-27-2003, 06:14 PM:
 
The 4 plex theater I work at has 4 seperate booths, so no one ever spends too much time in them when the film is running and I actually want to take out the filthy, oil soaked carpet (Simplexes) but I worry that the noise leakage into the auditorium would be too much to ignore. The port glass is a thin piece of glass slid into two runners. The booths are small enough that I could add the acoustic wall tiles, but would rubber anti-stat mats deaden the noise at all? We also have a problem with static in these small booths and I hope that replacing the carpent with anti static mats will help.
 

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Posted by Steve Kraus (Member # 476) on 02-27-2003, 06:17 PM:
 
Daryl, can you recommend any sources stateside for the compressed fiberglass with facing? The post house I used to work at used it in their 3 screening rooms but I wasn't there when it was installed.

I don't know if it's a good idea to paint them as that's bound to affect the acoustical properties.
 

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Posted by Gordon Bachlund (Member # 124) on 02-27-2003, 06:21 PM:
 
This thread has been fun to watch, especially for one like me who remembers the booths of fifty plus years ago, some of which had steel-clad walls, floors and ceilings, and most of which had battleship linoleum floors and hard concrete walls and ceilings. Perhaps this was part of the motivation to keep booth equipment well maintained and lubricated.
 

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Posted by Paul G. Thompson (Member # 655) on 02-27-2003, 07:30 PM:
 
Randy, you hit that on the nose when you described the ringing in the ears sound.

That's one of the reasons I like to have some kind of steady noise when I am in a quiet room to drown out the ringing, especially when trying to sleep. That ringing noise drives me nuts! (Of course, I am probably half-nuts anyway)
 

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Posted by Martin Brooks (Member # 1269) on 02-27-2003, 09:14 PM:
 
Here's a chart of the maximum exposure times in Hours/Minutes/Seconds beyond which OSHA considers hearing damage to take place.
(DB, A-Weighted)
SPL Time HH:MM:SS
80 25:24:00
81 20:10:00
82 16:00:00
83 12:42:00
84 10:05:00
85 8:00:00
86 6:21:00
87 5:02:00
88 4:00:00
89 3:10:00
90 2:31:00
91 2:00:00
92 1:35:00
93 1:16:00
94 1:00:00
95 0:47:37
96 0:37:48
97 0:30:00
98 0:23:48
99 0:18:59
100 0:15:00
101 0:11:54
102 0:09:27
103 0:07:30
104 0:05:57
105 0:04:43
106 0:03:45
107 0:02:59
108 0:02:22
109 0:01:53
110 0:01:29
111 0:01:11
112 0:00:56
113 0:00:45
114 0:00:35
115 0:00:28
116 0:00:22
117 0:00:18
118 0:00:14
119 0:00:11
120 0:00:09
121 0:00:07
122 0:00:06
123 0:00:04
124 0:00:03
125 0:00:03
126 0:00:02
127 0:00:01
128 0:00:01
129 0:00:01
130 and > 0:00:00
 

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Posted by Daryl C. W. O'Shea (Member # 1303) on 02-27-2003, 09:28 PM:
 
Steve, I'll see if I can find out where we've been purchasing the panels. Roger's out on tour right now so it might be a few weeks.

As long as it is a light painting with a roller, we've found it doesn't make much of a difference in a larger room. It also looks a heck of a lot better than the stock off-white colour.
 

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Posted by Gordon McLeod (Member # 33) on 02-27-2003, 10:08 PM:
 
Be aware that in most locations TBAR ceiling create a pleum and as such the tiles must be fire rated and cliped in place
 

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Posted by Kara J. McVay (Member # 1285) on 02-27-2003, 10:27 PM:
 
I am sitting here right now with that lousy ringing in my ears. I have to fall asleep with the TV on, so it masks the ringing.
 

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Posted by William Hooper (Member # 71) on 02-28-2003, 02:17 AM:
 

quote:

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The best tiles to use would be the sound absorbant ones. They're about an inch and a half thick and have insulation on the back (top) of them. Avoid using 'solid' tiles. Even the thin 'flexible' tiles would be better than 'solid' ones.

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Some of those acoustic tiles deteriorate like mad after a year or so. The ones that have the texture of a thin coating of dry plaster on the lower side seem to be the worst: a film of white dust on all surfaces, a plaster-y taste in the area, & evidence of respiratory irritation in personal air filters everywhere (with white, instead of black dust in the filters). The HVAC unit filters clog up with the white stuff too.

It's not neccessary to cover ALL the wall with Sonex or a Sonex-like material. Typically in studios, only above chair rail height is sufficient. For noise abatement only, simply spaced panels or ones in effective locations is sufficient. You'll find a lot of guys who do field recording take a few sections of Sonex mounted on 3'x5' or so panels with attached easel-type props around with them & get sufficient to excellent reverberation control or isolation.

As for dust, Sonex with the varying horizontal & vertical ridge patterns does collect it. It's mostly on the horizontal surfaces. There are Sonex knock-offs with ridges that run only one way, & if installed vertically, they are not dust collectors.



[ 02-28-2003, 03:24 AM: Message edited by: William Hooper ]
 

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Posted by Daryl C. W. O'Shea (Member # 1303) on 02-28-2003, 02:33 AM:
 
Plaster coated tiles are what I avoid. I was referring to the plastic coated ones with the yellow insulation on the top. They do not flake apart at all.

[ 02-28-2003, 12:00 PM: Message edited by: Daryl C. W. O'Shea ]
 

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Posted by Gordon McLeod (Member # 33) on 02-28-2003, 07:28 AM:
 
Sonex is highly flamable as some IMAX projectionists at the 3M dome discovered many years ago when the remains of an exploded lamp breached the base plate and ignited the sonex that they had lined the lower compartment of the projector with to quieten the beast
We used to have sheets of Sonex hanging in several places and got told to remove them as they did not have a suficient verticle flame rating for a"electrical room"
 

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Posted by Steve Kraus (Member # 476) on 03-01-2003, 12:32 AM:
 
After the recent Rhode Island tragedy I would not want any sort of foam unless I had personally put a match to a sample to see what it did, but given the propensity to collect dust I pretty much ruled that stuff out anyway.
 

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Posted by Joe Redifer (Member # 3) on 03-01-2003, 01:10 AM:
 
I thought my booth was noisy, being only 125' long and 12' wide with tile floor, cinderblock walls, drop ceiling and 6 noisy Simplexes ticking away. But the average level is 73dbc and it peaks at 82dbc right between two projectors that are back to back. I was absolutely amazed that it is so "quiet". I was hoping to force my employer to install carpet but no such luck. Maybe they will carpet the booth for my birthday or something.

I always have a slight ringing in my ears that I can hear during absolute silence if I listen for it. I've had that my entire life and have been told that it really is nothing to worry about. It is not disturbing. I can still hear the whine of a TV when it is on, and I can tell if a TV or monitor is on or off just by listening for that whine. My Linksys router emits a fairly loud whining/ringing sound. Weird! Like it was mentioned somewhere above, I do occasionally experience a louder ringing that gets pretty loud for a few seconds and then goes away for no reason. This has also happened my entire life. It happens maybe once every few months. Doesn't seem to have any ill effects but what the hell do I know?
 

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Posted by Steve Kraus (Member # 476) on 03-01-2003, 11:08 AM:
 
TV horizontal whine (NTSC), off the flyback xformer or CRT yoke, is ~15,734 Hz.

As for the ringing in Joe's head, well, it's slowing driving him crazy.

OK, not slowly.
 

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Posted by William Hooper (Member # 71) on 09-19-2003, 01:19 AM:
 

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I'm thinking of nicely faced compressed fiberglass panels.
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That stuff works pretty good Steve. We've used it in some larger recording studios where sonex foam wouldn't work much better due to the large space. The nice thing about fiberglass panels is that you can paint them.

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It's amazing how many people just don't give a damn about their employees' work environment

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