CONVERGENCE

If your going to play them loud and if your amp is manufactured in China ,chances are it might let dc voltage pass through which will destroy or pop your speakers. Use a commercial amp made in US preferably. It's worth to spend a few hundred or thousand dollars on a good amp. Power is measured as 2X the speaker wattage. Under power amps could clip and destroy your HF drivers. You will have better performance and ease of mind. ..................................

Yes go for it if you can afford it. But there will always be that Block Buster movie like the upcoming Indiana Jones that people will not wait for the HD DVD . The 72 foot screen will give you an experience that a top notch home movie cannot reproduce. There are private screening theaters in LA for movie makers. These are equipped like a real theater. ............................

This theater is 2 theaters of 1000 seats .What appears like tables in the second picture are actually cardboard boxes. That gives you an idea of the leg room between the seats. In one picture there seem to be a ledge between the seats. The speaker system seems to be only 5.1 with 3 speakers behind a 72 foot screen seems to be under the required size for 1000 seats. An 8.1 system would have been preferable. A lot of money went into decoration. Theres always room to convert to 8.1 in the future. ..............................

Tere is a curved screen for cineplex. The corners are bit fuzzy if not installed properly. The curved screen needs a long throw panavision anamorphic lens and preferably a 70mm print. Here is a new theater called Marcus Majestic The new Marcus Majestic Cinema in the Town of Brookfield is like no other movie theater in the Milwaukee area It has a 72 feet screen . This one is slightly curved . Being curved gives a visual throw back efect at the viewer, The speakers UltraScreen. Curtain .............

Read this first. ....... You can't improve on the Uptown. .......................... The Projectionist point of view. Quote: Well it has now been over a year since I worked the Uptown...I was one of the projectionists at the Uptown from 1988 until 2005. After college, I only worked Saturdays though. I can honestly say, we had the best show in town. What some projectionists think as a clean/sharp print woudn't cut it at the Uptown. The screen is so big and curved, any damage just shows up more and scractches take on a curved appearance. Focus was another issue. 35mm is too small a gauge for the Uptown's screen. The relatively poorly made prints of today really don't have a great focus to begin with..combine that with the small gauge and the deep curve screen, which taxes the depth of focus of the lens, and you have a very tricky arrangement. While I was there, focus was checked at least every 5-minutes to ensure it is at its best. Some films were just a demonstration of futility. CinemaScope films being the worst for the Uptown due to lenses adding the most to the image challenges. 70mm is the only format the Uptown should run. It is the only format that has the resolution, light throughput and the projection lens at the Uptown is designed for the curved screen. Yes, even 35mm blow-ups to 70mm would make (and have made) HUGE differences. As for DLP...it is definately is not up to the task at the moment. The depth of focus is not up to the task, the resolution is not good enough either. While I know that Jodar posted above about the Crown (I was part of that installation team...at least on the original system), but you are comparing apples to oranges. Technicolor limited us to 40-foot wide screens for those installations so they WOULD look good and bright. While they are in many ways quite good, they are not really at the level that cinemas should be striving for. 35mm film has the capability to exceed even 2K DCinema. DCinema needs to try and meet/exceed 70mm capability and offer an improvement. As for the Uptown's sound...it suffers from lack of attention combined with being played with by the latest special show that comes to town. The equipment within the place is quite good and you won't do much better just by replacing it (in fact you will most likely do worse). The Uptown's sound systems is quite similar to the Senator's in Baltimore, MD. Altec A-4 stage speakers, JBL subwoofers, Altec A-7 surrounds (12 of them), QSC amps, and the Dolby CP200 (upgraded). Probably the best the Uptown sounded was back when three of us tuned the room for a Paramount film with Al Matano...we had three analyzers going for the various zones throughout the room...one could really balance it out better than even with just a multiplexed mic system...and then critical listening was done by several people rather than taking just one person's opinion. As some have discovered...the sound in a room that large can vary quite a bit...a bit tinny downstairs towards the screen (in the middle, particularly), and notably subdued in the balcony. Then again, many techs don't realize there are two HF horn systems for each speaker to properly cover the Balcony and main section separately. The potential to have good sound there is indeed doable...just not every tech is up to the task nor has the time available (nor prior experience) to do it.

Theres one theater in Washington Dc . Washington Post Editorial Review "The" place to see a movie in Washington is unquestionably the Uptown. In this day of generic multiplexes, the Uptown theater carries you back to the era of the movie palaces. It has only one screen. But, wow, what a screen. It's curved, 40-feet high and about 70-feet long. Installed in 1966, this eye-popper helps sell more than 200,000 tickets each year. Jack Valenti, the president of the Motion Picture Association of America, says the screen "is probably the best we have in this town." The second great attraction is a balcony with stadium seating. It almost feels like being at a drive-in without having to look over a dashboard. A $500,000 renovation project in 1996 brought high-back velour seats with drink holders along with new wallpaper, flooring, carpet, drapes and a second concession stand. While the refurbishing didn't take away that old-time feeling, it did take away seats; capacity dropped from 1,120 to 850. More than 300 seats are in the balcony. The sound System Altec A-4 Main 5 of them. JBL subs Altec A-7 Surround 12 of them. .......................

Yes the HPS 4000 looks like the K Grand . The interior might be different. It's SMPTE aproved thefore the quality must be quite good. Here is a photo of your conventional JBL University auditorium theater. ...............................

The Klipsch commercial series is doing well. In almost evry major city in the US we can count at least 10 to 20 theaters equiped with this make. Here ia a resize picture in a soffit mount . j

I've got new photos of an Altec theater set up with A-4 by Tom Loizeaux. Quote from Tom Loizeaux. For the past week I've been setting up a theatre space by rolling three full-sized speakers into position. It's a pleasure to push 3 Altec 4A, dual 15 cabinets (w Altec 515s), with wings, into a line. On top there are JBL 2446H drivers attached to JBL 2360B horns. They are on wheels, but at almost 10 feet tall and about 800 lbs. each, it's a push for sure. Then I roll in a pair of JBL 4642A dual subs into position. When they power up you're really covered in a BIG sound. I used to think my 4343s were big, but these Altec monsters make my 4343s look like bookshelf speakers. Tom passed away last year .He was a true professional . The Giant Folded horn type theater speaker is making a come back ...................................................................

I made a mistake here Linearity is important and subs should be RTA for Fr 15 to 125 HZ . Then SPL can be adjusted. Sorry for the commotion.

Theaters don't RTA subs. The Fr range is usually Any where from 20 to 200 Hz . They measure the SPL with a meter and set at between 80 and 90 DB. It should match the rest of the system So do an SPL check with out the subs . Of course you should RTA your system if your main speakers and surrounds separately and average it out. Theaters use a multiplexer to do this .The EQ is 1/3 octave 27 band. But all this is professional . All you need to adjust is the SPL level of your subs with a meter.

In order to test your speakers you need an equal signal on both channels. Do you have a mono switch on your pre amp . By playing a CD in monophonic you will be able to tell if it's the speakers that are defective. GMX A-2.1 System If it's set up on your computer . If you can't play them in mono take them back to the store and get a new pair. Just say you think one side is louder than the other.Or you want your money back.

Is your system hooked up to a receiver or preamp that has a mono function. If played in mono with balance function in middle. If the sound still comes from one side rather than the other. Then you might have a weaker speaker. These are the small cubes by Bose. They are like tweeters . More fragile than a 8"speaker for example. Do you still have the warranty?

I had mine repaired in mid 70's by Engineering dept.Cost me around 60$ . They corrected some manufacturer mistakes on top of that.

DR WHO QUOTE How does one determine which caps need replacing? I've never tore into the inside of one, but I would imagine replacing all the caps would be rather expensive... You have a point since old caps values are different than todays caps. For ex: They made 21MF caps back in the 80's now you only have 20 and 22 MF. That's why I would rather leave it to the pros like ALK. Anny way that should be the last thing to modify on a sound system. First thing should be speaker components conditions. ...........................................

You would be better to check with GPA for ORIGINAL diaphragms. For example On large Drivers GPA uses pascalite which is stonger. http://www.greatplainsaudio.com/ ..........................................................

The unequalized frequency response of the ALTEC A-5 is the same as the A-4 with Wings. The reason is simple The A-5 is a front loaded Bass Reflex Horn The new 515- 8G are more efficient than the older ones. And with brand new processor Dolby CP 65.there was no need for Subs . The back stage was also acoustic treated . Booth Equipment 35mm Projector Simplex XL 35mm Film Head, Serial #4761 Simplex XL Sound Head with LED reader Strong Ultra 80 Lamp House 3000 Watt Xenon Bulb Speco LP 280 Platter System 16mm Projector Kodak Eastman Model 25B 16mm Film Head, Serial #1832 Oracon Lamp House 1400 Watt Xenon Bulb Sound System CP 65 Dolby Processor CM 35 Booth Monitor 3 QSC MX 1500 Amplifiers Phillips 5 Disc CD Changer 3 Altec A-5 Main SpeakersThey got themselves the most efficient sound system for that size of auditorium. ......................

AES OR RMS ? jOKE ha ha. There are really only two diaphragms to consider aluminum and Pascalite. Some say the Aluminum has slightly better highs. At best it's marginal. The Pascalite has a different alloy and a carbon fiber former, allowing it to handle more power. The aluminum should be considered for home stereo only. They blow too easily for live sound use I'd have to ask what horns you are using? I HAVE used the Aluminums down to 300, but they certainly won't handle much power. The problem is the excursion. The diaphragm has to move so far to produce a longer (lower frequency) wave. So if you crank them, they will blow. If i wanted to go to 300 LOUD I would use Phenolics. ......................

I'm still waiting for the Ampex litt. to be scanned. In the meanwhile I stumbled on a new site. It's an old theatre restored with 3 Altec Lansing A-5 as main speakers. http://www.thelyric.com/tour/start.php

There is a pair on EBAY for 1500$. Here are some pics.

You need the right horn wich is the exponantial horn with K55 driver. MF XO is 400 HZ. Martinelli manufactures for ALK Engineering a wooden exponantial horn for the K55.With the correct horn your Xo sonic properties will be matched. An alternative would be the Altec 311 horn wich starts at 300 Hz and a 290 driver. As for the ALK Horn they mentioned having to make the hole bigger for the La Scala. http://www.alkeng.com/ http://www.woodhorn.com/BMS/bms_compressiondrivers.htm

Hi Garyrc, As for literature very lilte is available. These speakers were Lansing produced. Ampex bought the equipment to manufactured them . Please read the following quote from Steve Schell. Steve Schell 09-18-2005 10:47 AM I can add a little to what Don said. Ampex made a major effort to penetrate the theatre sound business in the 1950s, and chose JBL to provide the speaker systems. Westrex (export arm of Western Electric) was also looking for a supplier of theatre sound gear, since Western Electric had recently ceased making this equipment due to a consent decree with the U.S. Government. They also chose JBL to make much of their equipment. The 375 driver was developed to meet the need for a stout high frequency driver for these systems. We have heard conflicting stories as to who actually initiated the design effort, but it is evident that they were being supplied to the two companies by 1953 if not earlier. Actually AMPEX was ordering more product than JBL, still a small company at te time, could supply. To meet their need, they opened their own factory in North Hollywood and built their own versions of the JBL products, paying JBL a royalty on each unit produced. I think that the Westrex 375s were built by JBL, as they look very similar to the early bubble back units used in the Hartsfield. Note that the 375 had been developed for theatre, not hi fi use. The Ampex products for certain, and likely the Westrex products as well, were in production well before the 375 was applied for hi fi use with the introduction of the Hartsfield in 1954. "Jim Lansing Theatre Sound System" of 1954 (Also Manufactured as Westrex T550 and Ampex 6000C) © Harman International, Courtesy Mark Gander and John Eargle

Hi Garyrc According to Steve Schell from the Lansing Group He knows the fellow who took down the system in the Coronet and the Alexandria. Quote" I spoke today with the gentleman who removed the big Ampex systems from the theatres in San Francisco years ago. His name is Paul Mundt. He said that the woofers were installed in large bass horns with mouths 7' by 7'. In addition to the four 15" 375 pot woofers, each horn used a 10" mid bass driver and had an unusual phasing plug structure in the throat of the horn. A friend of his will be scanning and emailing to me some original Ampex literature on this horn, which was part of the Todd-AO system. I will post the images here when I receive them. I'm beginning to suspect that these 375 pot woofers may have been a special model produced by Ampex for Todd-AO. Paul also mentioned that these systems used special high frequency horns consisting of what appeared to be modified Altec 1503 multicellulars. Each horn used two 288 drivers on a Y throat, oriented vertically instead of the usual horizontal arrangement. There was some sort of perforated metal screening installed in the horn throat as well. Convergence, the two theatres were the Alexandria and the Cononet. I looked them up on the Cinema Treasures site and read that Mike Todd had personally supervised the installation of his system at the Alexandria in preparation for the debut of Oklahoma in September, 1956." These Ampex woofer speakers were manufactured by Altec Lansing for Ampex According to The Altec unofficial site. That clarifies the story of those theatres. http://audioheritage.org/vbulletin/showthread.php?p=134747#post134747 post 29

The folded horn cabinet still being produced today in large quantities . Here is a picture of an earlier model from 1975.

Hi Garyrc, I think the superscoop were part of the 4250 series.Some were rear and others front loaded. I had a pair but they were short throw compared to an A-7 for example. Or had to be played loud to get to the rear of the theatre. Most of these models ended up being used by rock groups instead.They still did not meet the SMPTE standard for picture movies. The A-7 was used by early rock or country signer "Elvis Presley"by replacing the 416 by a 421 Woofer and 808-8B Driver with 511 horn.This model was more powerful but not SMPTE aproved. We had to wait till the mid late 80's for JBL to replace the venerable VOTT. If you go a few post back you have the model by Ev And Altec next to each other.