The Hub: Just call it UBANGI !

When a product is tagged with nomenclature like "MI-9462", you can bet that it's intended for either military or industrial usage. The RCA MI-9462 was indeed industrial, a loudspeaker system intended primarily for movie theaters. You might know it by its nickname: "Ubangi".

The MI-9462 had distinctive horn "lips" protruding from the front of the bass cabinet. An anonymous wag thought the lips resembled the cosmetically-extended lips of Congo tribeswomen exhibited in circus sideshows. A Ringling Brothers press-agent billed the tribeswomen as being from the (non-existent) "Ubangi" tribe; he later admitted taking the name of the exotic-sounding Ubangi River.

Now, what about that giant speaker? Some background is in order.

Harry F. Olson should be included in any list of titans of the audio world. Olson received his PhD in atomic physics in 1928, joined RCA to work in sound-recording for films, and was made head of acoustics research in 1934. Olson's 77A microphone and LC-1A speakers are legendary, but the most astonishing aspect of Olson's 40-year career with RCA is the range of his work. As detailed in a 1975 IEEE interview, his designs included the first practical synthesizer, a phonetic typewriter, a quadraphonic recording and playback system, and development of the RCA video disc system! Olson also wrote several pioneering texts on acoustics and sound, and is perhaps best-known for his systematic analysis of speaker-enclosure types.

RCA's professional audio products during Olson's reign showed original thought, exceptional performance, and elegant appearance. Jonathan Weiss of Oswalds Mill Audio has assembled a treasure-trove with both an RCA museum and an archive of RCA literature. (We may examine other RCA classics in the future, including the MI-1428 field-coil driver, inspiration for the Cogent drivers.)

Weiss points out that "Ubangi" was not designed by Olson, but by John Volkmann and A.J. May, and had to be "that big" ( 7 feet long) in order to reach down to 35 Hz. Like most theater systems, "Ubangi" was a two-way; its bass enclosure combined a front horn with rear reflex-loading, topped by a horn-loaded compression tweeter. The MI-9462's enclosure was more complex than most Western Electric or Altec enclosures, and some systems are still in use as professional monitors, a testament to their performance (performance not even hinted at by the RCA data sheet for the MI-9462).

The system featured two MI-9411 woofers per enclosure; intact original units are rare, as the paper cones tended to deteriorate. The compression driver is the MI-9548/9584, which Weiss says "... is arguably the best sounding permanent magnet compression driver ever made for the lower midrange, i.e. 200 Hz on up. " Either 60- or 90-degree horns were used, or both. Response drops off above 8kHz, but within its range, "Ubangi" is said to be coherent, dynamic and startlingly lifelike.

Considering the thousands of sound systems that once resided in American movie palaces, not many have survived. Of the survivors, many were sold in decades past to dealers and collectors in Japan, who appreciated Western Electric and Altec systems long before we snooty American audiophiles did. Oddly, although several RCA systems (including this one currently for sale on Audiogon) were at least as good as W.E. and Altec systems, audio archaeologists often bypassed the RCA gear.

Why? No one paid big bucks for it, like the Western Electric gear. RCA equipment is more in demand now than ever before, but prices are generally still far below W.E. levels. It remains to be seen if that means that there are still many old RCA systems waiting to be discovered in warehouses and old theaters, or if most were consigned to landfills.

In that regard, searching for old audio gear is a lot like fishing: there are always stories of "the one that got away".
Gad I remember those and have heard them. In the late 60's the Palace Theater in Dallas, Texas was being torn down and my office building was next door to the Palace. I remember the workers taking six of these out to the huge trash container, as well as other items. Basically gutting the place before demolishing the building. I had always thought about getting a couple of them, but where was I going to put them. I am glad you posted this as I never knew what they really were, now I know - Thanks Bill.
If I ever move to a movie theatre or build a 15K sq ft mansion I'll be looking for 1 of these beauties.Interesting read,reminds me of the article of those subwoofers which took up whole basements.Forget the magazine,thanks once again for your time and energy,bob
Interesting article. Thanks!
Thanks for the kind comments.

Back in the '80's, the Orpheum Theater in Memphis was being renovated, and I was asked if I was interested in the '40's-vintage RCA sound system. Being one of those idiots who thought only WE gear was worthwhile, I turned down the offer.

More dumpster fodder. Ah, the things that'll give you indigestion at 3 in the morning....

Thanks for taking the time to write, guys.
A-1 Audio in Las Vegas, NV used arrays of these bass bins in their concert PA systems from the late 1970's through the '80's. At the time, A-1 was the main audio contractor for the Vegas casinos and sent systems out on tour with entertainers such as Frank Sinatra, Barbara Streisand and The Doobie Brothers. I heard their systems several times in different venues and I was always impressed with the overall coherence and clarity they had.
If you view the credits in any of the thousands of Hollywood movies made from the late 1920's through the mid 1960's you will see either the Westrex or RCA logos prominently displayed in them. As far as film sound was concerned, they were the "only games in town". These two companies manufactured all the parts of the recording and playback chains used for each and every one of the major studio releases of the time, from the microphones, preamps and film recorders used on the sound stages to the playback amplifiers and speakers the public heard in the theaters.
While Westrex's California location gave them a local connection to film industry people, RCA's New Jersey based design team had several significant advantages of their own. First, RCA engineers had access to feedback about their work from world class musical talent through both a national radio network (NBC) and a major record label. Secondly, RCA had sold millions of their radios and phonographs to the general public.
Thanks for the thoughtful posts.

In terms of resources and number of technological developments, I view RCA as the audio/electronics equivalent of General Motors. Both had the opportunity to produce absolutely world-changing products but for the most part, didn't. Like GM, RCA some incredibly arrogant and just plain bad marketing decisions.

The difference is that GM still has a certain amount of life to it. RCA? What they heck do they do, these days?
RCA was run by David Sarnoff, who was notorious for being incredibly arrogant. It has been said that Sarnoff's blatant theft of Major Armstrong's FM patents led to Armstrong's suicide. Sarnoff awarded similar treatment to television's inventor, Philos T. Farnesworth.
Sarnoff at least stuck to the radio side of things.

Most of the greats were robbed in one way or another. Don't even get me started on the subject of Tesla!
A qualification to dbcat's reference to Philo Farnsworth, which I suspect dbcat is aware of but others may not be. Farnsworth invented ELECTRONIC television, as opposed to the spinning disk technology which preceded it (with limited adoption of course).

Here is what appears to me to be a good overview of the Farnsworth/Zworykin/RCA controversy:

Bill, thanks for another great article!

Best regards,
-- Al
Because you seem to be a stickler for details, I would prefer that you abbreviate my screen name properly. In the engineering world, the word "Decibel" is abbreviated as dB, so my name would be shortened to dBcat.

However, the real Decibel the Cat is watching me as I post my comment so I have to mention that he prefers dB__^..^__

dBcat, I stand corrected! I'll try to be more purr-fect in the future :-)

Best regards,
-- Al
Those are my Ubangis in the photo. I live in Charlottesville Va. and would welcome anyone interested in hearing them to get in touch. I have them loaded with 4 EV 15W speakers and am using a Tratix type horn with a pair of Altec 288-K drivers. Power is with 2 Altec 1570's rebuilt and improved by Tom TuTay. Far and away the best audio Ive heard anywhere at any price including Wilson Alexandria's (awful), Magnapan 20.1's (nice but difficult load and setup), Klipschhorns (nice but somewhat fatiguing highs) These thins do it all and do it well. Howard