Identify Theatre Speaker for me?

[16hz lover]

Back in the small town I grew up in, the old theatre is still standing. I recently contacted a buddy to see if he would stop by and find out if they still had the same speakers in it that they had when I was a kid. I graduated from High School in '74 so I would bet they are 1950/1960 models? He did just that yesterday and the owner took him in the back and showed him this big horn system---1 speaker only. They had just recently shoved it over to the side and are wanting someone to take it out of there. It is one big bass bin that is about 7 ft tall and a horn array which has 3 rows of 4 cells in it. You can see in the dark pictures that there are two bronze colored compression drivers at the bottom of the horn. There is also a control box which you can see at the top of the RH side of the bass bin. He said there were very large cables going up to the top where the horn assembly was.





Anyone know exactly what it is?

Thanks

[Earl K]

- Steve Schell is the expert here for this vintage ( RCA ) stuff .

- First off ( IMHO ), you should make arrangements to obtain this stuff today / you'll regret a delay ( if I'm right about my assumptions ). Some of what I see is highly collectable .

- The horn appears to my eyes as an RCA multicell / the horn-drivers in the background are RCA ( field-coil types ) from the 1930s.
- They'll either be MI-1425(s) or MI-1428(s).
- The model difference ( I believe ) is mostly in the voltage necessary to energize the field-coils . In case you don't understand, the drivers have no permanent magnets / so without a charging voltage they won't work .

- The bass bin appears to be a Shearer horn from the same era . The woofers ( therefore ) are also likely to be RCA .

>< cheers

[16hz lover]

- Steve Schell is the expert here for this vintage ( RCA ) stuff .

- First off ( IMHO ), you should make arrangements to obtain this stuff today / you'll regret a delay ( if I'm right about my assumptions ). Some of what I see is highly collectable .

- The horn horn appears to my eyes as a RCA multicell / the horn-drivers in the background are RCA ( field-coil types ) from the 1930s. They'll either be MI-1425(s) or MI-1428(s).
- The model difference ( I believe ) is mostly in the voltage necessary to energize the field-coils . In case you don't understand, the drivers have no permanent magnets / so without a charging voltage they won't work .

- The bass bin appears to be a Shearer horn from the same era . The woofers ( therefore ) are also likely to be RCA .

>< cheers

Earl: Now you have me excited Would there be more than the two field coil drivers behind the multi-cell horn? So the box over to the side that had the big cables coming out of it provide the juice for the drivers?

[Earl K]

Would there be more than the two field coil drivers behind the multi-cell horn? So the box over to the side that had the big cables coming out of it provide the juice for the drivers?

- I don't honestly know if RCA made an adapter that allowed for 4 drivers to enter a single horn-throat .

- Steves' the man in the know about this stuff .


>< cheers

[Steve Schell]

16hz lover, it appears to be an RCA Shearer Horn type system that dates from approximately 1937 to 1941. The high frequency drivers are either type MI-1428B (13VDC field coil) or type MI-1443 (115VDC field coil). Mounted to the rear of the folded horn W bin will be two 15" field coil woofers type MI-1444 (115VDC) or MI-1432A (13VDC). The compression drivers used to sell for very little, but people have discovered their excellence and pairs have been bringing $4,000 on ebay. The woofers fetch around $2,500 to $4,000 per pair with original cones in good shape.

I can't tell from the dark pictures whether the 12 cell horns are the early encased style or the later cardboard cell variety. Most of the early ones had an integral, vertically oriented Y throat for the dual drivers, so this is probably a later horn... later being after about 1940. The 1400 series drivers disappeared from the RCA literature after 1942. They weren't made after the war due to cost considerations.

Good luck in your attempt to obtain this equipment. What, you're still reading? Go!

[16hz lover]

Thanks Steve for the quick reply. My buddy is going to contact the owner of the theatre tomorrow morning. It seems I must have contacted him at the right moment as he told my buddy they were going to "get rid of them" soon because they needed the space. I would have never thought while growing up there, that I was listening to these same speakers , watching my first James Bond movies, the Sound of Music, Bullett(Steve McQueen), etc.

The bass bins are going to be the big obstacle, getting them in and out of most doorways. Do they have a 40 or 30hz cut-off? I could have sworn that I also watched the movie " Earthquake " as a kid in that same theatre. I'll let you guys know if I acquire them...I just missed yesterday on the local Craigslist a pair of JBL L250 speakers for 40.00 (woofers needed new surrounds)., so maybe I'm due for a score on some speakers.

I have been trying to read up on these this afternoon on the web and found one site that showed a frequency response of a 1428 driver and it stated that it was good from 130hz up to 10K...is that right? I am interested in trying the 1428's mated up with the AG500 horns from Acoustic Horn Co., if that would be a good match?

[Steve Schell]

The RCA Shearer type systems were a direct result of the Shearer Horn development project at MGM Studios in the mid 1930s. RCA lent their assistance to the Shearer team and their resulting products conformed (AFAIK) to the Academy Research Council specs. These included a frequency response of plus or minus 2dB from 50Hz. to 8kHz. This was actually a wide bandwidth for the era, as the optical soundtracks of that time offered little except noise beyond those boundaries anyway.

You mention the bass bins in plural... are there two of them? RCA offered two or three models of bass bin with single woofer back then, plus the large double woofer model as seen in your pictures. In the largest systems the double woofer bins were laid horizontally and double stacked for four woofers of low frequency awesomeness.

You should know that in most cases with a system like this the drivers and horn are scavenged and the bass bin is left for the wrecking ball along with the theatre. One time I bought a pair of MI-1444 woofers and parts of the MI-1456 bass bin were used to build the packing crate. An intact system like this one is very rare in 2009. The drivers tend to survive because audiophiles in recent decades (mostly overseas) have discovered that they have no equal. If I were a rich man I would seek to preserve a few of the remaining systems intact and keep them in running condition.

As to the big box with the cables... the usual field supply (DC supply for the driver field coils) had four rectifier tubes and was housed in a big black steel box. So was the dividing network, with all of its huge industrial components in a similar box. Grab all of this stuff if you can as it is all useful, quite valuable, and difficult to reproduce. Same goes for any of the projection booth equipment that may still be there somewhere; preamps, amps, dividing networks, etc. Building owners generally regard it all as refuse, but it is gold! Many theatres used to keep spare diaphragms, cone kits, even spare drivers on the shelf to keep the show running. Look in every nook and cranny for buried treasure.

If you can obtain this system, I suggest that you remove it in its entirety and set it up as a superlative mono playback system. It may be most practical for you to orient the bass horn horizontally and place the multicellular horn on top. Prepare to be blown away, as these RCA components are capable of incredibly fine sound.

[louped garouv]

AWESOME!

please keep us posted on how everything goes....

and go buy some lotto tickets too....

[16hz lover]

Well.....the unbelievable happened....just got off the phone with my buddy who went to the theatre and the lady there told him that they unbolted the big horn and took it to the dump. So he goes to the landfill and looked through the metal section, and a guy there asks him what he's looking for and proceeds to tell him that he remembers the lady tossing it into the back of the trash truck which went to the other landfill.(and also crushed within the truck).

The bass bin is still there so now he's on his way back down there to see if they will give him the cabinet so I can at least get the two woofers out of it.

Un FRIGGGIN believable....I'm shaking, I'm so mad....Makes me physically sick.

[16hz lover]

Well, it gets worse.

My buddy goes back down to the theatre and gets around the back of the speaker to look at the woofers and one is missing So now we are down to one field coil woofer and the control box. He went and told the owners how big of a financial mistake they made so they scurry off to the landfill thinking they are going to find the horn, but they came back and told him that they guy said that all those deliveries had already been buried. So another piece of audio history is gone. He asked the owner why they tossed it when we had told them we wanted it, and supposedly the third owner got in a hurry and wanted it out of there....couldn't wait I guess.

I have been reading alot about The Other Side and why we are here (to perfect ourselves further and learn) and for the life of me, I cannot find one thing positive about why this has happened. All it has done is make me extremely bitter towards that piece of crap, small town I was unfortunate to have been born in. Unfortunately, I will sometime have to return for a funeral, but then and only then will I go back there. I just don't get it.

Have I told you how pissed off I am right now?

[oldsoundz]

Total Bummer!

Very sorry to hear it.

My condolences...

[Steve Schell]

I am sorry to hear about this sad event. If it is any comfort, the majority of superb prewar theatre gear met the same fate. It wasn't until the 1970s that it began to be sought after, and most of the early stuff was long gone by then.

Do try to get the woofer and any other odd RCA bits. Check the projection booth and storage areas if you can; you never know what might still be there in a dusty box.

It might even be worth offering the guys at the dump several hundred dollars each for the drivers if they could find them... how deep can they be buried?

[16hz lover]

If I ever meet that asshole who ordered the speakers thrown away I will use the National Lampoon Christmas Vacation quote,

"I want to tell him what a cheap, lying, no-good, rotten, fore-fleshing, low-life, snake-licking, dirt-eating, inbred, overstuffed, ignorant, blood-sucking, dog-kissing, brainless, dickless, hopeless, heartless, fat-ass, bug-eyed, stiff-legged, spotty-lipped, worm-headed sack of monkey shit he is. Holy shit (mod edit: "looser") he is. Where's the Tylenol?

Excuse me while I go throw up my supper.

[16hz lover]

Well, we got what was left. A bass bin RCA MI-9456 with one MI-1444 woofer and the control box/rectifier??? components all intact. Will post pictures as soon as my buddy in Kentucky sends them to me. So anyone in central Kentucky who would be interested in the bass bin, let me know. I don't know if there is anyone who could put this to good use, but we will try to sell it very reasonable before it too meets it's demise.
I just imagine that unloaded, it will not be worth much. Any suggestions on which way to find a new home for the one woofer and controls?
I can't imagine what the hell they did with the other woofer.

[Tom Brennan]

If I ever meet that asshole who ordered the speakers thrown away........

Excuse me while I go throw up my supper.

It was his to throw away. It's just old stuff, not worth getting a grabber over.