RCA Ubangi [Archive] - Lansing Heritage Forums

JBLGUY

01-20-2005, 10:21 PM

I have never heard that name " Ubangi " before. but of course the horn on top is an Electrovoice. I have several of those horns with drivers and they sound very nice indeed. Now at the same time a freind of mine also has a set and they sound awful at his house. Differant setup I suppose.

That just goes to show you that the same horn and driver can sound so differant when using differant equipment and rooms. This points out the need to tune each horn system after setting it up.

Anyway I bet that cabinet kicks out some serious bass.....look at the size of the cabinet behind the woofer. Very large volume indeed. These ultra big boxes really put out the low grunt because of the huge volume behind the woofer.

Steve Schell

01-21-2005, 12:54 AM

That bass enclosure is an RCA model MI-9462, designed by Mr. A.J. May of RCA in about 1950. Mr. May was the understudy of Mr. John Volkmann, famed RCA speaker engineer and inventor of the radial horn. They were built from the early 1950s through the 1970s.

The 9462 was the heart of RCA's larger postwar theatre systems. It is a combination front horn and bass reflex enclosure, similar in concept to the large Altec Lansing VOTT enclosures. Where it differs is that it was intended to be used horizontally only, and incorporates a 90 degree radial exponential front horn. This horn closely matched the horizontal pattern of the cast aluminum 90 degree radial mid / high frequency horns typically used with it.

As to the term "Ubangi", it is a slang term often used to describe the 9462, based on its appearance. Here's and excerpt from a post by Patrick Currie on the Joelist in 1997:

"...there was an African tribe that went to extreme and, depending on one's perspective, grotesque measures in stretching out there lower lips by punching a hole in the lip and then inserting progressively larger flat wooden discs in the hole. The results ultimately were hugely stretched lips with impressively large wooden discs inserted. So: a) these may have been the Ubangis, and, b) this would account for someone naming a large horn system, perhaps politically incorrectly, after the tribe."

Now having covered all of that, I have to admit I have never heard a pair of these set up as intended. Many of them have been cut down to more manageable proportions by hobbyists over the years and retuned to a lower resonant frequency. They were originally tuned for maximum efficiency rather than ultimate bass extension, like the big Altecs.

RacerXtreme

01-21-2005, 03:50 AM

It looks impressive doesn't it ?

I bet they thump.

I've searched the internet for more info, but there's not much. A place called Mann's Chinese Theatre in California had them for it's P.A. system but that was years ago. Wish I could find some blueprints..........:banghead:

Very, very interesting..................:bouncy:

:applaud:

Guy

RacerXtreme

01-22-2005, 05:29 PM

How's this for thump?
http://www.mypages.iparenting.com/webs/racerxtreme/dual18s2.jpg
My 4WD Jeep Liberty looks pretty small eh?:blink:

Guy

mikebake

01-22-2005, 05:34 PM

What are the drivers?
What is this system for?

Don McRitchie

01-22-2005, 05:48 PM

Now having covered all of that, I have to admit I have never heard a pair of these set up as intended.

You had one in your garage!!! How could you miss that opportunity???

Actually, I saw your qualification. I just couldn't resist :D

Steve Schell

01-22-2005, 06:57 PM

Hi Don,

Yeah, ain't it the truth! I had a pair of MI-9462s in my workshop for a year or so. They had been A.J. May's personal pair, with which he used to supply sound for the 4th of July celebration in his home town of Haddon Heights, NJ. He used to enjoy checking the power being fed to the speakers while they were going full blast, and said that occasionally the one watt lamp would flicker.

I gave that pair to a fellow in Simi Valley, Ca. He restored them to as-new condition and runs them as mains in a hi fi setup. He also has two systems running with Altec 210 cabinets; he likes to do things in a big way.

RacerXtreme

01-22-2005, 07:04 PM

Hi Steve,

has this friend of yours modified his 210's in any way? Does he have an A2 or A4 system? How does he like the Ubangi's and how do they compare to the V.O.T.T.'s ?

Thanks,

Guy

RacerXtreme

01-22-2005, 11:07 PM

There were Eminence drivers in the dual 18" sub cabinets. They sounded great. They came from a local nightclub that re-did their P.A. Whoever built them did a nice job. I was using them for x-tra low end in a sound system I'm building in my garage. My neighbors love me......

andywin

01-23-2005, 05:23 AM

RacerXtreme

01-23-2005, 06:34 AM

Thanks for the cool photos. :applaud: That's the first time I've ever seen an RCA horn setup on top of a Ubangi. Those cabinets appear to be slightly larger than my Altec 210's which are 7' tall (84"), 39" deep, and 32.5" wide. What did the RCA horns sound like? Are they really hard to find? I think I know the answer...........

Guy

Steve Schell

01-23-2005, 09:00 AM

That photo in Mr. Briggs' book depicts the PL-301A system. Top of the line was the PL-301, similar except that it stacked two of the bass enclosures. The horn above the MI-9562 is an MI-9595 90 degree radial horn. Above it is an MI-9594 60 degree radial horn. These were also designed by A.J. May. In this setup, two compression drivers on a Y throat fed a splitter which fed the throats of both mid/high frequency horns. The 60 degree horn was aimed at the balcony in a theatre installation.

RacerXtreme

01-23-2005, 12:02 PM

How did it sound? Were the mid and high freq.'s bright and crisp or dull and boring? I realize it's 1950's technology, but I had to ask.

Guy

Steve Schell

01-24-2005, 10:47 AM

These systems used the RCA postwar style compression drivers, MI-9584 mostly. These have a dome style phenolic diaphragm with half roll compliance. RCA never entered the "specs" war, and only claimed response to 8kHz. This is accurate, and the radial horns dispersed it over the full 90 degrees. This was adequate for these systems' intended purpose at the time. For modern hi fi use these drivers provide a thrilling midrange reproduction on a proper large, low cutoff horn, but a tweeter needs to be used with them.

As to my friend with the 210s, he restored them to original condition I believe, instead of hotrodding them with additional bracing etc. His system configurations change frequently; he was running dual 288s on H-1803Bs up top the last time I talked to him. I'm not sure how he likes the MI-9462s in comparison to the Altecs.

Lawrence HF

01-24-2005, 07:08 PM

I had the pleasure to hear it about 30-35 yrs. ago, and got two MI 9594 horns, and MI 9591 horn to driver adaptors. I use one horn on center speaker system with JBL2482, and mounted above that use JBL2345 I think is the number with Altec 902 at 1.5K Hz, and a couple 075's. Don't play it all that loud, but smaller speakers don't please me that much anymore. When I heard RCA systems, 2 in stereo, 60 watts each, was very impressed.

EdSawyer

01-24-2005, 08:10 PM

I have a pretty mint pair of 9595's with the MI9584 drivers. It's a great sounding horn, rated to 200hz by RCA. Very smooth dispersion, even when listening from not that far away. Definitely better sounding than any JBL horns I Had to compare with. The only thing better sounding (Which I am now using) were 300hz round wood tractrix horns (ala Edgarhorns). The RCA horns are quite nice, very well made, and heavy. Damped with external materials too, which is nice.

-Ed

RacerXtreme

01-25-2005, 02:41 PM

Hey Ed,

how much power can they handle? Do you have a blueprint or know
anyone with a blueprint of the cabinet? Just out of curiosity, if they were
for sale, how much would you ask for them? I may keep my eyes open for a pair - or try to build some copies. I have no idea what they're worth.

How long have you owned them? Ever have a chance to compare them to Altec 210 VOTT's ?

Thanks for the info.

Guy

Lawrence HF

01-25-2005, 03:12 PM

Hi Ed, You have the 9595 90-degree, mine are MI 9594 60-degree by probably 40-degrees. Mouth 24X12, length from bug screen about 33". Very good for mid range only, tried a driver I know goes well to higher freqs. and those higher freq. don't make it out of horn. I put my head in looking for them, could not find. Used more sophisticated intruments also, then went 3-way, and finally 4-way. I like it, others I'm sure would not.

John

01-25-2005, 04:27 PM

Hi Guy I have seen those once on ebay a couple of years ago. I cannot remember what they went for,but i would think alot would depend on the distance between seller and buyer. Keep a eye out for closed down movie theatres in small towns and find out what,s inside. You might get them for free just for removing them from the theatre.http://audioheritage.csdco.com/vbulletin/images/smilies/bouncy.gif

RacerXtreme

01-26-2005, 04:48 AM

Where can I find a blueprint for the cabinets?

:D

Guy

packrat

08-01-2005, 11:22 PM

I actually have access to three of these cabinets without the speakers and two horns without the drivers. Along with 4 MI-9377 amps which are all coming out of a theater in Indiana. I plan on putting them on Ebay for the people renovating the theater to raise some money. Anyone interested?

tomt

08-02-2005, 10:11 AM

medwin say he might sell some of his

http://db.audioasylum.com/cgi/m.mpl?forum=hug&n=90162&highlite=ubangi&session=

icarus53

08-06-2005, 10:20 AM

Hello, Packrat!

Nice to say hello to you.
I am really interested in Ubangis and MI9595 horns.
May I open private discussions with you?
Please send emails to [email protected] at your earliest convenience.
Thanks.

norealtalent

08-15-2005, 09:07 AM

I just came into 3 ubangie cabs and a pair of A7 votts. One RCA is empty. Two of the RCA's are loaded with a single 31 lb #9449 15" woofer and #9597a crossover complete with coils and both cans and weighing in at 25 lbs EACH complete unit. The woofers are pristine. I haven't been able to find much on these. The cabs had the factory RCA number on them but I did not write down the cabinet number, just pulled the components. I knew better when I left the cabs but didn't want to spend my vacation running around renting and driving a Uhaul home. When I got home I found this: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5795550338&ssPageName=ADME:B:EF:US:1
I've already contacted the man and will be retrieving all the cabs this weekend, if not sooner. ANY information on the RCA's would be greatly appreciated.
Thanks, Dave:bouncy:

Steve Schell

08-15-2005, 11:50 AM

Hi Dave,

This RCA equipment has historically been shunned by collectors, being regarded as inferior to the Western Electric gear. Now that the supply of W.E. has dried up, there is new interest in RCA and prices have been rising steadily over the past couple of years.

The bass enclosures you described, if similar to but shorter than the MI-9462 and configured for a single 15" woofer, are type MI-9588. They seem to be less commonly encountered than the 9462.

The 9597A crossovers operate (I think) at 250 ohms in and out. They sell well on ebay, and I often wonder if the buyers are aware of their impedance. If you have the round, black cans, these are model MI-9471 impedance matching autoformers. They were used to transform the 250 ohm impedance down to whatever was required for the high and low frequency driver(s) used in a particular system. These are high quality, wide band autoformers and can be used for level matching by do it yourselfers as well as impedance matching. I am using a pair of these to pad down the midrange/high frequency drivers in my home system. They have been selling on ebay lately for at least $100 each.

The MI-9449 woofers are very fine horn drivers, similar in concept to the earlier Altec 515 woofers. These often suffer from failure of the outer hinge on the cone, but are worth quite a bit if the original cones are in good condition. Be careful with these, as the cones are thin and fragile, and no suitable replacement is available as far as I know.

I was surprised at the selling price of the MI-9462. Until recently it was difficult to give these away due to their size and weight, although there has always been a cult of enthusiasm for the robust performance of these boxes.

norealtalent

08-15-2005, 12:58 PM

Thank you Steve!!! Gonzo told me to pm you but I didn't want to be a pain. I added a couple of pics. The cones show NO sign of stress cracks whatsoever. These things are absolutely beautiful. One basket has a little scratched spot, otherwise they are as close to new as when installed. I can't wait to hear them in their cabs! I hated leaving them but didn't want to push the wife factor any further than necessary. Thanks again. I'll post an update when I know more.
Harmonies, Dave

norealtalent

08-21-2005, 04:27 PM

You nailed it Steve, MI -9588's. Thanks for your help, Dave:bouncy:

newbaymiao

03-02-2011, 02:00 AM

I am looking for the RCA Ubangi. Any one interst in selling?

16hz lover

09-17-2011, 01:58 PM

I am looking for the RCA Ubangi. Any one interst in selling?

I have one for sale, but I'm on the other side of the world from you. It is loaded with 2 JBL 2226 drivers in it. I guess shipping from North Carolina to Hong Kong would scare you away unless you REALLY wanted one.
http://i11.photobucket.com/albums/a180/hobie1dog/Audio/P1030511.jpg
http://i11.photobucket.com/albums/a180/hobie1dog/Audio/P1030512.jpg

Steve Schell

09-17-2011, 11:20 PM

I once briefly owned a pair of MI-9462 cabinets that had belonged to their designer, the late RCA engineer A.J. May. A.J. had used them for years to provide sound reinforcement in his home town of Haddon Heights N.J. for the annual Fourth of July celebration in the city park. A.J. told me that one time he attached a watt meter during use and only occasionally saw the one watt indicator lamp light up. I gave the 9462s to an acquaintance who had meticulously restored several big Altec theatre systems and promised to do the same to the 9462s. I fell out of touch with him and fear that he may no longer be earthbound as he was a BIG guy with health problems. The MI-9462s however are eternal...

Cyclotronguy

10-05-2011, 12:36 PM

Steve;

If I'm not mistaken Jonathan Weiss of Oswald Mills fame has one.

Kent

16hz lover

10-05-2011, 12:50 PM

Steve;

If I'm not mistaken Jonathan Weiss of Oswald Mills fame has one.

Kent

The one he has pictured on his site has the ports butchered off of it, which is a real shame.

blakehoo

11-16-2011, 02:57 PM

16Hz lover is in NC & I bought the 3 speakers that Dave is pictured sitting on.
I'm in Henderson NC, now. I was in Charlotte which is closer to Cornelius.
Thought that was odd, so rejoined and posted.

1audiohack

11-16-2011, 03:03 PM

Funny how things move around, the one pictured and offered for sale by 16Hz lover is in a truck on it's way to me as I type this. :^)

blakehoo

11-16-2011, 08:13 PM

Damn funny all this activity on a 6 yo. thread...
I wanted to compare sonic pressures.
...& as loud as they can get!!

Is this a new center channel for you?

16hz lover

11-16-2011, 09:21 PM

the Ubangi is sold and on it's way to Las Vegas now. It was just taking up too much real estate for my 2 car garage system...gotta maximize floor space. When we measured the response on the PC, the mic registered 120db average SPL with music with 110 watts on it.
http://i11.photobucket.com/albums/a180/hobie1dog/Audio/P1040099.jpg

Lee in Montreal

11-16-2011, 09:49 PM

http://2.bp.blogspot.com/_HMkmWL3cTOI/S1i4EVUOc9I/AAAAAAAAAPM/cWcoKInzIXc/s1600-h/SYSTEM.gif

Those seem to be a diffrent version.

16hz lover

11-16-2011, 10:09 PM

http://2.bp.blogspot.com/_HMkmWL3cTOI/S1i4EVUOc9I/AAAAAAAAAPM/cWcoKInzIXc/s1600-h/SYSTEM.gif

Those seem to be a diffrent version.

once again, they have cut off one side of the ports, I don't get it:blink:

1audiohack

11-16-2011, 11:09 PM

Is this a new center channel for you?

I don't know what it will be, yet. Just looking at it something in my head says yeah, that just looks right and I'm betting it is. One things for sure, I'm going to see how loud it plays, you just have to!

One of my prosound pals told me of another prosound guy that stood these on end and loaded what became the top port with a 2350 or two and four bullets and toured with them. Crazy.

blakehoo

11-17-2011, 03:28 PM

I don't know what it will be, yet. Just looking at it something in my head says yeah, that just looks right and I'm betting it is. One things for sure, I'm going to see how loud it plays, you just have to!

One of my prosound pals told me of another prosound guy that stood these on end and loaded what became the top port with a 2350 or two and four bullets and toured with them. Crazy.

Congratulations! That's exactly what happened to me in 2005!

These 3 are in storage now, but I tried many combinations of drivers with them ...and man they are smooth... You need to use RCA horns with them. They perfectly match the 90 degree RCA horns ...so the combo sounds like its a solid wall /curtain of single sourse sound ...even up close. I like using altec 290 horn drivers with these horns. The 290's have phenolic diaphrams like what were stock with this system ...and of course that lets you approach the lower frequency this horn is capable of reaching.
Three way would of course be best with the combo, but I never got around to choosing a tweeter before I sold the house.

I currently have a home theater style set-up of unmodified Bill H. designed 288/299 "duplex box" altecs' with his 290 based driver box as a center channel. Nobody else knows what this is, but it is basically plug&play and works where I'm at now. You know Bill as the former Altec chief engineer who now runs GreatPlains audio.

What's up with the chopped off ends? I don't know. Once I sealed them off (temporarily) to use altec 411 drivers. The 411's did sound great in the enclosure but those sound good in just about any sealed box. ...so Who knows?

herki the cat

12-10-2011, 02:41 PM

....What's up with the chopped off ends? I don't know. Once I sealed them off (temporarily) to use altec 411 drivers. The 411's did sound great in the enclosure but those sound good in just about any sealed box. ...so Who knows?

Well, Mr. John Volkman, RCA Camden Photophone chief engineer designed the seven foot wide MI-9462 Ubangi Horns together with his brother in law, Dr. Harry Olson who developed the differential equations for this horn system. These two giants knew the importance of the Ubangi seven foot width dimension that people have been defeating by chopping off the ends.

This modification ruins the frequency response below the 60 Hz cutoff of the horn flare component. In this mode, the driver sees inductive acoustical impedance. Drivers with heavy cone assembly and FS of 30 Hz may sound great except for the damaged transient response and group delay in this quasi sort of an infinite baffel spectrum.

This design was very carefully executed in a $1,000,000 RCA anechoic laboratory [Been there]. The original Ubangi horn design is capable of excellent performance down to 30 Hz. Ce tout.herki[Quote]

1audiohack

12-16-2011, 11:46 PM

Wow, I'll tell ya wow!:bouncy:

With a 9dB parametric cut centered at 153Hz, and a Q of 1.5 it's fairly flat from 35 to 1kHz and pretty good from 40 to 750 Hz. It has that sound I hoped it would have, like a 4550 only bigger and it kicks like a mule.

Functionally in half space with an honest 1.2kW input and a solid output of 120dB SPL at 3M the cabinette scarcely trembles, it is very well built. I'll have to put the laser on it but I would guess cone travel at that volume is maybe 0.375" and for sure less than 0.500" Dangerous fun to be sure!

I must find it a mate! I have a couple of leads. 54099OK I am going back out there!:D

16hz lover

12-17-2011, 08:13 PM

Glad it performs to your expectations. I have located more of them:D

herki the cat

12-17-2011, 10:20 PM

http://2.bp.blogspot.com/_HMkmWL3cTOI/S1i4EVUOc9I/AAAAAAAAAPM/cWcoKInzIXc/s1600-h/SYSTEM.gif
Those seem to be a different version.

In link:http://2.bp.blogspot.com/_HMkmWL3cTO...0-h/SYSTEM.gif (http://2.bp.blogspot.com/_HMkmWL3cTOI/S1i4EVUOc9I/AAAAAAAAAPM/cWcoKInzIXc/s1600-h/SYSTEM.gif)The image has four RCA MI-9462 Ubangi's & each one has a port side chopped off. RCA Photophone did supply double stacked Ubangi's with a compliment of four MI-9449 LF Drivers. In 1953, RCA had three of these double systems in the RCA Camden Corporate Office Building#2 Demo Room. The three channel Film sound demo was awesome.herki[Quote/]

jw5115

12-21-2011, 02:45 PM

Will be in vages for CES and would like to hear Ubangi Bass
jw5115 [email protected]

bigyank

01-02-2012, 09:25 AM

Glad it performs to your expectations. I have located more of them:D

Any near southeastern PA? :D

Goldie

05-22-2014, 10:15 AM

Thought you all might enjoy seeing what I'm building. The 9462's are constructed from Joubert, Okeume plywood. Okeume is an African mahogany like wood. The plywood is 9 ply, all Okeume, marine grade. Each sheet is certified to British boat building standards by Lloyds of London. The horns re wooden replica's of Altec 1505's, done in Tilia, also own as Basswood, using all natural glues and shellac.Current drivers are Electro Voice 15W's and Great Plains Audio 288 Alnicos. Production models will us GPA 515 Alnicos. Options include TAD, or field coil drivers. They're not cheap but for those who want the finest audio has to offer I'm at [email protected]

Goldie

05-22-2014, 10:23 AM

Im also working on the RCA horns in wood. Make it complete.

Carl_Huff

05-22-2014, 10:26 AM

Very impressive and huge! Even by my standards.
_____________
Best Regards,
Carl Huff

1audiohack

05-22-2014, 09:28 PM

Wow those are very nice. Recreating these was no small feat.

I finally have four of them and double stacked they are fearsome!

Thanks for sharing!

All the best
Barry.

stephane RAME

05-25-2014, 12:54 AM

http://johannes30.exblog.jp/22020302/

Stéphane

tomt

07-20-2014, 11:41 PM

http://johannes30.exblog.jp/22020302/

so hardcore , his accomplices must remain anonymous ...

http://i.imgur.com/3kvzOeP.jpg

Altec Best

08-04-2014, 04:50 PM