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.
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".
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".