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Topic: Sensurround

Martin Frandsen
Master Film Handler

Posts: 270
From: Denmark, Europe
Registered: Jun 99

posted 02-01-2000 03:47 PM

I never had the chance to see any movies in 'SENSURROUND' has anyone on the forum? Was it that awsome to see 'EARTHQUAKE' in sensurround or was it just another 'gemick' from Hollywood at that time.

How did it work, was it just very large subwoofers and lots and LOTS of power? How was sensurround coded on the film if so and was it true that theaters did fall apart like in the movie 'Matinee'

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Serge Bosschaerts
Film Handler

Posts: 70
From: Schoten, Belgium
Registered: Jan 2000

posted 02-01-2000 04:00 PM

I heard the following of a sensurround equiped cinema in Luxembourg :
the owner thought that the number of subwoofers proposed by the installer wasn't enough so he doubled it.
Result was that the first time they played Earthquake the hotel next to the theatre was evacuated because people were convinced a real earthquake was happening ...

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Stefan Scholz
Expert Film Handler

Posts: 223
From: Schoenberg, Germany
Registered: Sep 1999

posted 02-01-2000 04:36 PM

There have been different types of how Sensurround sound worked. The prints could have either been optical, or magnetic sound. In common was the use of "extra" subbass speaker cabinets. With magnetic sound, a seperate track was used, optical worked simelar to the DTS subwoofer, by cutting the low end with a filter, as I remember about 80 Hz and feeding this signal to the woofer cabinets. The frequencies above 80 Hz were then fed to the theatre loudspeaker.
The print's music and dialogue therefore sounded a little "thin", lacking the usual bass response. This was used on my "Rollercoaster" print. The Earthquake I had, had one or two (I'm not sure)tracks dedicated to LF.

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Greg Mueller
Phenomenal Film Handler

Posts: 1687
From: Port Gamble, WA
Registered: Jun 99

posted 02-01-2000 06:26 PM

I saw two films in Sensurround. Earthquake and Midway (war flick) It was an amusing experience, but not if you were in the theater next door. When I saw it they had some very large folded (I think) corner horns with 2ea 18" Vega subs in the rear corners. You could deffinately tell when an earthquake was comin cause you could hear the horns "turn on". I saw a couple of people freak and run for the door. Earthquake was a pretty bad film, and really only had the rumble effect to sell it. Midway was better, as far as film content, but the only sensurround effect was bombs exploding etc. much like the subwoofer effects we have to day, except turned up to loud. I wish I could have seen some of the other "catch" gimicks of the 50's like electrified seats (The Tingler) and Smell-o-vision (no kidding).

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Gordon McLeod
Film God

Posts: 9532
From: Toronto Ontario Canada
Registered: Jun 99

posted 02-01-2000 06:45 PM

Earthquake was rushed in production so actually the original Sensurround box hd a pushbutton to push for the shake effects.
The optical versions used notched edges or a filter or a control tone.
They also usd DBX noise reduction
The 70mm and 4 track mag earthquake used LE/RE for the quake effect and the four track had a tone on the control track
The theatre had to order the print to match there control cabenet.
There were 2 different earthquake cabineets both made by Cerwin Vega. In fact at Cinesphere we use 4 of them for subs on the cp200
At the Penn Centre in St Catherines Ontario the effect was so powerfull the booth floor seperated from its slab and sank 2 inches
at the Elaine theatre the shockwaves killed all the goldfish in the petshop at the otherend of the mall
Low frequencey sound can and is used to implode buildings and at one time the french government was experimenting with it a weapon.

Funny the W bins by cerwinvega seem very sinilar to what Klipsh now makes for there large cabeniet in the HPS4000 systems

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John Walsh
Film God

Posts: 2490
From: Connecticut, USA, Earth, Milky Way
Registered: Oct 1999

posted 02-01-2000 09:07 PM

I saw "Earthquake" when it first came out, at the theater I would later start my projection carrer.

I'm pretty sure it was the old system, where the projectionist would cue it manually. It seemed sort of fake, because it was like there was only two settings: little rumble and big rumble. It became predicable. You felt the exact same 'little rumble' in every scene, until the climax when you would get the 'big rumble.' The only clever/creepy thing in the whole movie was when the elevator doors open and water comes out.

By the time "Rollercoaster" came out, they had improved the rumble magnitude adjustment, and had automated it, but the quality of the film plots (never that great to begin with) really sucked. Sensurround belongs in the same catagory as 'Smell-O-Vision,' 'Emergo,' 'Tingler,' and other gimmicks. The Academy Award people must have been really bored that year to award it an Oscar.

When I started working at that theater, the Sensurround people had left the 'shorty' (about 4ft high) equipment rack. There were two BGW amplifiers and a 'control box.' I barely remember opening the control box, and was a little surprised how empty it was. There were very little electronics in the box. They also had mounted a toggle switch on each projector, next to the solar cell. I never did know what exactly that switch was for (Gordon?)

They also left about 8 50-60ft lengths of thick gauge romex wiring, which ran from the amps out to the speakers, which we swiped for surround wires at another theater. We also bought the speakers, and used them as regular sub-woofers at a third theater. Sounded pretty good, too.

As a side note: In the IMDb "Trivia" for Earthquake it says: "The first film to be presented in surround sound."

Also, that the TV show "The Jetsons" in 1962 was presented in Sensurround.

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Pete Lawrence
Expert Film Handler

Posts: 192
From: Middleburg, PA
Registered: Aug 1999

posted 02-01-2000 11:03 PM

I was working as a relief operator when "Midway" came out. One screen in the four-plex was equipped for 'SENSURROUND'. They installed the subs across the front under the screen and placed two standing up in the back near the exit. These things were big enough to walk in(if it weren't for the chicken wire.) I don't remember how much power they were pushing, but it was a full rack of amplifiers. I watched a preview and remember being impressed by my pant-legs moving when the bombs dropped and the subs kicked in. Other than those few scenes, everything was about normal in glorious monophonic sound. The overall effect in the theater "Midway" was playing in was interesting. In the third theater over it was incredible! And that was a different film! Needless to say, they only used the 'SENSURROUND' system once. The next time I worked they had removed everything. Oh well.

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David Johnson
Film Handler

Posts: 54
From: Melbourne Vict Australia
Registered: Oct 1999

posted 02-02-2000 02:50 AM

There are still a few cinemas around today that use the old Sensurround subs for digital subs.
David

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Gordon McLeod
Film God

Posts: 9532
From: Toronto Ontario Canada
Registered: Jun 99

posted 02-02-2000 10:11 AM

The toggle switch turned the dbx card on
latter units actually had directional control of the rumble

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Bill Purdy
Expert Film Handler

Posts: 139
From: Seattle, WA
Registered: Oct 1999

posted 02-02-2000 11:11 AM

All this sub-woofer business made me go look in my dead files and sure enough I still have literature on one of the most interesting subs of all time. This thing was called the "Servodrive" (made by a company called "Intersonics") because it did not use a voice coil. Instead, it had a servo motor and a series of belts which pumped multiple cones inside a big folded cabinet. They could handle 400 Watts continuously and with a maximum cone excursion of about 1 1/4 inches they moved a lot of air. Some of their curves show spl's of 140 dB with a response ranging from 25 to 125 Hz. That's all well and good, but the real fun part comes from how and why they came to be. I quote from their literature:

"Intersonics Acoustic Engineers were contacted by researchers from Cornell University who were studying African Elephant communication in Kenya, Africa. These elephants are able to communicate over long distances (5 miles or more) by the use of very low frequency sound.................." and so on for half a page.

I had a chance to play with one once, and what I heard mostly was the clicking of the internal mechanism. It was too bad for I really wanted to have an excuse to install an elephant caller.

------------------
Bill Purdy
Comonent Engineering

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Dave Williams
Wet nipple scene

Posts: 1836
From: Salt Lake City, UT, USA
Registered: Jan 2000

posted 02-02-2000 01:44 PM

Our theater's soundsystem, while entry level at best, has been so well eq'd that you really cannot discern where the sound is coming from, just that you are in the middle of it. Our subs actually shake the ENTIRE BUILDING, and several times had the arcade next door comeing over to see if we were having problems. It got so bad that someone in the bathroom actually thought we were having an earthquake and wet himself trying to get out of there. Several lights had broken during showings of THE MATRIX. Yet we had not even passed the 85 db range. We frequently tell people in our ad to COME FEEL THE MOVIE. We have had to tone it down to avoid any further damage to the building, but you can still feel it. Todays new building are too safe and too sterile. Seeing a movie should be an experience, and sure why not life threatening. Take a chance man!

------------------
"If it's not worth doing, I have allready been there and done it"

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David Koegel
Film Handler

Posts: 55
From: Alexandria, VA
Registered: Jun 99

posted 02-02-2000 02:28 PM

I do remember reading about the military researching low frequencies for the purpose of disabling ground troops. From what I recall, when exposed to high power low frequencies, soldiers would double over and their lower alimentary canals (i.e., bowels) would start an abrupt evacuation (i.e.... oh, you get the picture). I believe the frequencies were below the threshold of human hearing, like 5 Hz and below.

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Martin Frandsen
Master Film Handler

Posts: 270
From: Denmark, Europe
Registered: Jun 99

posted 02-02-2000 05:25 PM

Well it sounds like i did not miss anything from those 'SENSURROUND' days after all!
I'll stick to dts and turn up the subwoofer output if i want to go wild!

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timothy johnson
Film Handler

Posts: 50
From: minneapolis, mN 55419
Registered: Jul 99

posted 02-02-2000 06:04 PM

I have a video of battlestar Galactica, and in the credits it says "presented in Senssuround" is that true? did anyone see it that way? the video has mono sound, so was the film even in stereo? also, I have installed Clark Synthesis sub-sonic transducers, and I swear by them ! it is the next best thing for your home theater! it really rocks, far below hearing, my 8 theater seat shake, in addition to my 18 inch sub with 400 watts.

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Martin Frandsen
Master Film Handler

Posts: 270
From: Denmark, Europe
Registered: Jun 99

posted 02-02-2000 06:49 PM

For a small screening room (like mine) i like the ATC's or GENELEC's 1094 (they use(d) the GENELEC's at 20th Century fox sound stage) for large autoriums however i like JBL subwoofers.

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