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RacerXtreme
05-31-2005, 05:07 AM
Check it out.

http://www.mypages.iparenting.com/webs/racerxtreme/bighorns.jpg

RacerXtreme
05-31-2005, 05:12 AM
Photos from the Audiophile Club of Athens, Greece. :applaud: :D :) ;)

Rock and Roll.........:blink: :blink: :blink: :blink:

http://www.mypages.iparenting.com/webs/racerxtreme/bighorns1.jpg

pelly3s
05-31-2005, 05:54 AM
WHY DONT I HAVE THOSE

MatthiasA
05-31-2005, 08:14 AM
I love all kind of Horns :-)
Horns are great!

greetings Matthias

paragon
05-31-2005, 10:32 AM
Earthquake and more !!!

spkrman57
05-31-2005, 02:45 PM
I am still trying to unload most of my inventory to make room for my system to go downstairs in the basement.

Ron

RacerXtreme
05-31-2005, 04:22 PM
Are those horns (in the 1st photo) made out of concrete ???

Can you imagine coming home and telling your wife you want to build a new set of speakers ............. and end up with that ?

My wife would bury me in the back yard........:banghead: :banghead: :banghead: :banghead:


:blink:

Guy

RacerXtreme
06-02-2005, 01:56 PM
http://www.mypages.iparenting.com/webs/racerxtreme/hornz.jpg

Very, very nice............

RacerXtreme
06-02-2005, 02:00 PM
20,000 watts into this:

http://www.mypages.iparenting.com/webs/racerxtreme/hornz3.jpg

Ian Mackenzie
06-02-2005, 02:32 PM
Ah I don't know.....I get similar levels when I fart under the shower...!

:rotfl:

Ian

pmakres1
06-02-2005, 02:57 PM
Ah I don't know.....I get similar levels when I fart under the shower...!

:rotfl:

Ian

:rotfl:

norealtalent
06-02-2005, 03:08 PM
Ah I don't know.....I get similar levels when I fart under the shower...!

:rotfl:

Ian

Hence the obvious...

Drain Bramage


If you ain't got horns...
I know, I know, but I like to say it...
you ain't got *%#&!:moon:

RacerXtreme
06-02-2005, 04:11 PM
How would you like a pair of these?
http://www.mypages.iparenting.com/webs/racerxtreme/Molinear1.jpg

Titanium Dome
06-02-2005, 04:27 PM
Why is it every horns thread ends up looking like something our of Dr. Seuss?

I mean really, look at those contraptions! Can any natural sound come out of that? :rotfl:

RacerXtreme
06-02-2005, 04:58 PM
Doctor Seuss ???............

That's some nice work on those wood horns.

VERY nice.........:applaud:

Titanium Dome
06-02-2005, 11:31 PM
Doctor Seuss ???............

That's some nice work on those wood horns.

VERY nice.........:applaud:

Yes, they are quite beautiful and represent some serious effort.

Still, when I look at them, I can't help laughing, in the same way I look at some kid's 1963 Chevy lowrider rolling down Crenshaw with the front end hydraulics jumping up and down while a 2000W amp pushes a couple of 18" hyperbarics in the trunk, with some rapper shouting "F**k, f**k, f**k that bi**h: it's quite an accomplishment and a major personality statement, and I just sorta think :wtf:

Titanium Dome
06-02-2005, 11:34 PM
And yet, if I had that kind of skill and time and interest, I'd do it in a heartbeat.

Yeah, I mean the wood horns AND the car. Maybe the horns IN the car. :bouncy:

Mr. Widget
06-03-2005, 12:03 AM
Yes, they are quite beautiful and represent some serious effort.

I must second that! Furthermore I can't begin to think of the circumstances under which I would actually build a pair.... love to see them though. OK, I'd give them a listen too.:D



...I look at some kid's 1963 Chevy lowrider rolling down Crenshaw with the front end hydraulics jumping up and down while a 2000W amp pushes a couple of 18" hyperbarics in the trunk, with some rapper shouting "F**k, f**k, f**k that bi**h: it's quite an accomplishment and a major personality statement, and I just sorta think :wtf:

Damn... you are sounding just like your dad... but I know what you mean.;)

Widget

Steve Schell
06-04-2005, 08:55 PM
Hi guys,

The third picture posted by RacerXtreme was taken at Kevin Brooks' home in Provo, Utah. The black bass horn with the driver hanging from the throat was built by ALE (Audio Laboratory Endo) in Japan; Kevin is their US distributor. The driver is ALE as well.

When I was there nearly two years ago, Kevin was running a stereo pair of these ALE drivers and horns and experimenting with Lowthers in free air for mids and highs. He apologized for what he considered to be a lashed together system, but hearing those ALEs was a revelation. Never had I heard bass reproduced so faithfully, so effortlessly and devoid of coloration. The sound in their frequency range (approx. 70Hz. to 500Hz.) was the closest to real life I've ever heard. My partner Rich and I have been experimenting with long bass horns and compression drivers since then, but I'm not sure we've yet attained the "open window" clarity of the ALE components. One of these days I hope to return for another listen.

These large architecture horn systems may look a bit wacky and obsessive, well I guess they ARE wacky and obsessive, but oh man do they work!

johnaec
06-04-2005, 09:45 PM
Never had I heard bass reproduced so faithfully, so effortlessly and devoid of coloration. The sound in their frequency range (approx. 70Hz. to 500Hz.) was the closest to real life I've ever heard.What does he use below 70hz?

John

Marty
06-04-2005, 10:02 PM
[QUOTE=RacerXtreme]Check it out.

Hey Racer,

Do you know where this system is ?

It's quite impressive and looks Japanese. The bass horns could be a bit larger to get
20 HZ--and longer as it appears they do not extend through the wall (but I might be wrong).

johnaec
06-04-2005, 10:26 PM
Even extending through the wall wouldn't help if the mouth, (front), isn't big enough...

John

Marty
06-04-2005, 10:32 PM
Here's another one that some may not have seen .

glen
06-05-2005, 03:08 AM
Here's another one that some may not have seen .

Hey Marty,

That looks like an old variation of the featured "Listening Room" system No.482 in the May 2005 issue of the Japanese magazine "MJ Audio Technology". Although the system in the magazine features one W-bin in each bass section topped by a same-sized blank panel so the horn height is the same. The wall behind, and the blue floor look the same as your picture Marty, so I believe it's the same set-up, just shuffled around.

Anyway the MJ diagram identifies the components as old Western Electric units. The system is shown as WE TA-4181A field coil woofers + TA-7396 (woofer W-bin I guess), and the high frequency is WE 594 driver + 24A horn. Attached are some pictures of the drivers.

Titanium Dome
06-05-2005, 05:53 AM
Having a set up like that is quite the curiosity. It'd be like having a 1960s era Indy racecar in your garage. Sure it's fast and loud, but it's impossible to get new parts and who the heck would want to drive it to work everyday? :biting:

RacerXtreme
06-05-2005, 11:35 AM
Isn't that a Western Electric "Mirrophonic" sound system from about 1938 ?


:blink:

It looks pretty impressive for 67 years old.




Guy

Steve Schell
06-05-2005, 04:44 PM
RacerXtreme, those do appear to be Diphonic two way systems, part of the W.E. Mirrophonic system of the late 1930s. One reason they are so scarce is that they were almost ended before they began. W.E. signed a consent decree with the U.S. government on September 1, 1937, agreeing to cease providing sound equipment for use in U.S. theatres. An article introducing the Diphonic systems appeared in the Bell Labs Journal in their October 1937 issue, a month later. Apparently they had been producing systems for at least a few months prior to the consent decree; the earliest date I have seen on ERPI service literature pertaining to the Mirrophonic equipment is February 1937. W.E. may have continued production of some of the components for a short time afterward, marketing them for other uses such as auditorium sound reinforcement. They may have also provided equipment for installation in theatres in other countries after the consent decree, but not for long. The highest serial number I have seen on a 594A compression driver is about 2,400.

RacerXtreme
06-05-2005, 06:12 PM
How many of those systems do you think were made ? Not the individual components (like the 594a's) but the entire system ?

One more question. How many do you think have survived today ?

A guy from Italy on a Western Electric site I visited once, told me that most surviving Mirrophonic systems are owned by wealthy Japanese businessmen that pay upwards of $50,000 -$100,000 for a pair of them.

That's some serious coin.......

:biting:

c-ya

Guy

Marty
06-05-2005, 07:58 PM
Hey Marty,

Although the system in the magazine features one W-bin in each bass section topped by a same-sized blank panel so the horn height is the same.


Yes , those would be a TA-7396 Baffles ['TA' meaning "Theater Apparatus"]

The TA-7396/TA-7397 baffles came in two stacked sections called "63398 SPEAKER SECTIONS"
(which excludes the uneven-sized baffle wings). So each 63398 section could take two TA-4181 18" woofers.

Another version was the TA-7401 Baffle which was one 63398 "Speaker Section" topped with a 63429 "Blank Section"
(this sounds like the other variation you saw in the article)

Steve Schell
06-05-2005, 08:05 PM
It is impossible to determine but fun to speculate on how many of these systems were originally installed, and how many of the components may still exist in any usable form. If we assume that about 2,400 594A drivers were made, that is a place to start. Of course many of the systems used two drivers on a Y throat, and many theatres had spare units on the shelf for emergency repairs. Also considering the units that were used for other purposes, it looks like the number of complete Diphonic systems may have been less than 1,000.

As rare as the Mirrophonic equipment is, the products of Lansing Manufacturing company are even rarer. The only driver I've seen with a serial number much above 300 is the 801B small format driver as used in the Iconic. From the available evidence it looks like perhaps 1,500 Iconics were made by Lansing and the early Altec Lansing. There may have been only a couple of hundred Lansing Monitor systems, and perhaps a few hundred Lansing Shearer Horn systems before the field coil theatre system era ended about 1945.

It makes me shudder, but the majority of this fine performing, extremely well made gear may have gone into the landfill by the end of the 1950s. Often the field coil drivers were replaced on existing systems by permanent magnet units, using adapters to mate the newer drivers to the older horns. The rest has sat in abandoned theatres or warehouses until being rediscovered by the audio collectors and resale dealers. There has been a strong export market for the past 25 years or so, but the dealers are really having trouble these days as there is not much left. I do applaud the overseas interest in this stuff, as even more of it would have wound up in the dumpster otherwise.

Steve Schell
06-05-2005, 08:14 PM
John, Kevin was using some sort of fancy direct radiator subwoofer when I was there. Can't remember what it was, but as I recall the rear of the driver was exposed on the side of the box, and it was fancy looking with part of the magnet structure painted red. Kevin only used the sub for a portion of the demo cuts I heard; he left it off most of the time. It didn't sound bad, but to me nothin' keeps up with a full horn system like a front loaded horn sub.

johnaec
06-05-2005, 08:31 PM
W.E. signed a consent decree with the U.S. government on September 1, 1937, agreeing to cease providing sound equipment for use in U.S. theatres.What's the story behind this??

John

Marty
06-05-2005, 08:38 PM
How many of those systems do you think were made ? Not the individual components (like the 594a's) but the entire system ?

One more question. How many do you think have survived today ?
....
Guy

Steve gave some good clues as to production runs going by serial numbers
as I too have never seen 594's above the 2000's - and a large Mirrophonic used TWO 594's !

Production somehow continued after WWII as GRAYBAR were advertising 594's and my avatar picture
is from the 1940s MOTIOGRAPH catalog (Chicago). Though by the 40s Mirrophonic was too
expensive to compete it would seem . But systems went to Argentina, Australia, England.

Going by 594 serial numbers, I can't imagine more than 850 Mirrophonic Systems having been made.

Today, there may only be around 50 complete systems saved by fanatical collectors,
as , often, drivers & horns were stripped from theaters leaving the Baffles behind
(I've been guilty of that tasteless practice in the past).

Marty
06-05-2005, 08:54 PM
it looks like the number of complete Diphonic systems may have been less than 1,000.


Steve:

Looks like we posted at the same time but both agree on <1000 DIPHONICS made !

Steve Schell
06-05-2005, 11:07 PM
John, I have been fascinated by the U.S. government's dogged pursuit of Western Electric, but have not done any in depth research. From the details I have run across and old timers I have talked to, the following picture emerges:

From the late 1920s on, W.E. was the dominant force in the movie sound industry. Bell Labs did most of the groundbreaking R&D and W.E. (through their Electrical Research Products Inc. branch) manufactured the equipment. They would not sell the equipment to theatres, but insisted on lease agreements instead. This agreement included frequent service visits, performed by personnel from their All Technical Services branch. W.E. captured something like 80% of the market; their chief rival RCA had maybe 10% and all others the remaining 10%.

By the mid 1930s RCA was very upset about the situation, and appealed to the government to intervene in what they felt was W.E.'s monopolistic domination of the industry. Apparently W.E. had been tyrannical; charging very high rates for leases, service and spare parts, and insisting that theatre chains give W.E. all their business lest they lose the installations at their major theatres. By 1937 the guv't did lean on W.E., the leverage probably being the threat of breaking up AT&T. Although the theatre sound business had been intensely profitable for Ma Bell, it was tiny in comparison to their core telephone business. Remember how the old reliable W.E. bakelite phone was always leased, not sold? Anyway, W.E. signed the consent decree to cease providing sound equipment to U.S. theatres, shut down ERPI, and spun off All Technical Services to a group of its managers for a token sum. These guys formed Altec Service Corporation to continue as many of the theatre service contracts as they could, bought Lansing Mfg. Co. in 1941 and formed Altec Lansing Corporation.

**Sidebar** One of my favorite bones to pick is with the Altec historical accounts that state that All Technical bought the "nearly bankrupt" LMCo. to have a source of manufacture for the spare parts they needed to maintain the theatre service contracts. BS! This was only a small part of the story. Lansing was making the world's finest sound equipment at the time, and All Technical seized the opportunity to purchase the company's intellectual property as well as manufacturing capability of this equipment. As far as I can tell the new corporation could have resumed manufacture of the Mirrophonic equipment if they has desired to, but they never did. The Lansing products of the 1930s- compression drivers, horns, woofers, magnetics- marched right along under the new management and evolved into the major Altec products of the next five decades. Okay, I'll step down from the soapbox!

Later on, in September 1949, W.E. signed another consent decree to cease manufacture of all their postwar consumer and industrial speaker and microphone products. Rights to manufacture these goods were assigned to Altec Lansing, which began building these products immediately and supplying many of them back to W.E. as an OEM. Hmmm. I've never figured this one out. What had W.E. done to piss off the guv't. this time? Bell Labs had done their usual fantastic job of developing the postwar products: compression drivers, horns, direct radiators including 755A, 756A, 728B, 754A. W.E. advertised the new products heavily and began manufacturing them to stringent quality standards, only to have the guv't. stand on their neck and insist they stop. We'll never know how things might have evolved if the U.S. government had not drummed W.E. out of the speaker business, but I have to think that consumer audio would not be so bleak in the 21st century if things had gone differently. Damn.

Marty, it is a shame that very few systems remain in their complete glory, but I'm just thankful that the components were pulled from the W bins before the wrecking ball hit the theatre. If I were a rich man I'd have a large building full of operating systems, but at least a few of them are still up and running- an example of money in the right hands!

My recounting of history may be wrong here and there, as it has not been deeply researched. The tough part is in finding an impartial account from the old days. The editorials in the projectionist magazines of the times speak very obliquely of what was happening, rarely naming names. The accounts in the RCA and AT&T journals are very sanitized, whitewashed and corporate-centric. All I know is that nowadays we got no Western Electric, we got Bose.

Harryup
06-06-2005, 06:29 AM
Is there anyone that has a TA-4181-A for sale? I have one and would like to use a pair of them at home.

Harryup

harry_up@hotmail.com

Alex Lancaster
06-06-2005, 07:23 AM
:) Could a reason for the Gov to lean on Westrex, was that RCA was run by a General with great connections?

If Westrex had been so mean, etc, etc, wouldn´t everybody run to RCA?

I´m sure there is lots more to all this deal.

johnaec
06-06-2005, 07:24 AM
...the U.S. government's dogged pursuit of Western Electric, but have not done any in depth research.Interesting! Thanks for the info, Steve. 'Looks like big brother's been at it longer than I thought...

John

RacerXtreme
06-06-2005, 02:57 PM
When you guys say 850 or maybe 1000 systems were manufactured............
how many different systems were there ? Some appear to be quite a bit bigger than others.

On the Japanese site pictured earlier in this post, there's a picture of a TA7395 w/ a single 18" woofer that's absolutely HUGE. And it's not a "W" style cabinet (or baffle) ............and some are ? Is there a website where you can see all the different systems that were available ? What's a 4181 ?:blink:


Thanks for the history lesson :bouncy:


c-ya

Guy

Titanium Dome
06-06-2005, 03:57 PM
All I know is that nowadays we got no Western Electric, we got Bose.

True, true, one of the great What ifs? of all time. Yet, had W.E. survived to extend its monopoly, where would JBL be? Another Apple Computer sustained by a relatively small band of hard core supporters in a Microsoft world? :biting:

RacerXtreme
06-06-2005, 06:07 PM
What an AWESOME website. Guess you can visit this place,
(for a nominal fee)
and audition some of the vintage audio gear. :applaud: :D :)

Check out all the vintage Western Electric sound systems. Click on "English" if it comes up in Japanese and you can maneuver around a bit better. Some of the pictures won't load, but there are a couple of goodies........

Save this in your favorites:


http://www.wec.co.jp/index.htm


c-ya

Guy



(http://www.wec.co.jp/index.htm)

Marty
06-06-2005, 10:41 PM
John,

By the mid 1930s RCA was very upset about the situation, and appealed to the government to intervene in what they felt was W.E.'s monopolistic domination of the industry. ...
All I know is that nowadays we got no Western Electric, we got Bose.

Most interesting

I should have known RCA would have been a big part of the problem..
and RCA's systems were a load of crap by comparison IMO

RCA - again petitioning the Govt's help - also killed off other Color TV systems
in the late 40s
http://www.novia.net/~ereitan/Color_Sys_CBS.html

Marty
06-06-2005, 11:31 PM
how many different systems were there ? Some appear to be quite a bit bigger than others.

a TA7395 w/ a single 18" woofer that's absolutely HUGE. And it's not a "W" style cabinet (or baffle) ............and some are ? Is there a website where you can see all the different systems that were available ? What's a 4181 ?:blink:




TA-7395 Baffle:
is a 63409 conical horn SPEAKER SECTION
with 1 TA-4181 (18") LOUD SPEAKING TELEPHONE
plus a 63407 BLANK SECTION on top
plus a 63405 (24") WING on the left
plus a 63406 (36") WING on the right

overall: 7' 7" H x 9' 2" W x 3' 1" D
325 lbs complete LF but excluding HF

TA-7397 - Largest Mirrophonic: (pictured in avatar)
HF: 2 x 594A - 1 x 22B ('y') RCVR ATTACH & 1 x 26A HORN
LF: 4 x TA-4181A
12' H x 11' W x 3' D
1150 lbs - LF & HF

Steve Schell
06-09-2005, 09:27 PM
Marty, I agree that RCA's systems up through the mid 1930s were uninspiring; mostly 8" cone full range drivers in wooden horns. They really blossomed in the late 1930s though, when they began producing their two way Shearer type systems. At first they used drivers built by Lansing Mfg. Co., the 15XS woofer and 285 compression driver. During this period they worked intensively to produce their own drivers suitable for this type of system, and the incredibly good 1400 series drivers made their debut in 1937. The MI-1432A (13V field) and MI-1444 (115V field) woofers were similar to the Lansing woofers in concept. The compression drivers MI-1428B (13V field) and MI-1443 (115V field) were entirely different from the Wente type drivers like the 594A and the Lansings. Likely due in part to the struggles between RCA and W.E., they chose a different path technologically. They used a center-suspended silk and phenolic cone diaphragm with cloth outer surround, and a complex cast aluminum 15 section radial phasing plug. These drivers produce the best midrange I've ever heard from a production driver, just absolutely glorious. My partner Rich and I have been working steadily for the past two years to bring a modern version of this driver to market. Some details, though a bit dated now, are found in an article I wrote for my friend Jonathan Weiss's web site at http://oswaldsmill.com/id29.html

Sadly, the 1400 series drivers were dropped by RCA after WWII, and their postwar products never achieved the performance of their prewar ones.

I sure wish that W.E. had been able to remain in the market instead of being chased out. Although the Altec products based on the LMCo. designs were darn good, they embodied Bell Labs engineering from the early 1930s. There was suprisingly little true innovation for many years to come. We'll never know what Wente, Fletcher and their kind would have developed over the next several decades if they had been allowed to continue their work.

RacerXtreme
06-10-2005, 03:10 PM
Thanks for all the great info guys........

More big horns.............. Anything look familiar ?
http://www.mypages.iparenting.com/webs/racerxtreme/gotohorns.jpg

RacerXtreme
06-10-2005, 03:17 PM
Isn't that a 288 ?

http://www.mypages.iparenting.com/webs/racerxtreme/gotohorns1.jpg


Here's a shot of the back of the big horns. Dual Goto bass drivers ???
http://www.mypages.iparenting.com/webs/racerxtreme/gotohorns2.jpg

Now that's impressive.


Guy

mike.e
06-13-2005, 07:53 PM
-Would love to hear some of that old gear,compare it to recent stuff:blink:

Speaking of big horns...

http://homepages.paradise.net.nz/sbk1/sys.htm
http://homepages.paradise.net.nz/sbk1/sys_files/horn2.jpg

theres a 20hz basshorn on DIYAUDIO -'6090 horn' By a scandanavian guy,great stuff

Hi!

I just finished my brand new 8,8 meter long large format basshorn. Not quite done with the bracing and finish yet, but I had to do some listening tests with a crew from Norwegian national TV. And of course take some pictures:)


The 6090 Monster has almost flat frequency response from 18 to 100 Hz and has a low frequency limit of 9,7 Hz.
The transients were really impressive.
We played a recording of an earthquake and this is the first time I have heard the last ten seconds of that track even though I have subs with a 20 Hz limit in my living room.

I'm wondering if this is the worlds largest single 15" straight basshorn?

It is buildt in ten pieces, so it is kind of mobile;)

Best regards
Rune Skramstad



http://www.diyaudio.com/forums/showthread.php?postid=551368#post551368

Titanium Dome
06-13-2005, 10:45 PM
So no one besides me thinks this is a little nuts? Impressive, but nuts.

Marty
06-14-2005, 01:12 PM
Marty, They used a center-suspended silk and phenolic cone diaphragm with cloth outer surround, and a complex cast aluminum 15 section radial phasing plug. These drivers produce the best midrange I've ever heard from a production driver, http://oswaldsmill.com/id29.html



Very interesting ! Very Pre-War Esoteric ! I like those twist HUBELL connectors on the top.

The post-war RCA P.M. driver never got any respect - needed a Supertweeter - needed a BOSTWICK :D

I have a pre-war 1940 RCA Theater Amp (quad 6L6 , Selectable No Neg Feedback Mode ) Interested ?

Steve Schell
06-14-2005, 02:16 PM
Hi Marty,

Some folks these days are discovering that the postwar permanent magnet RCA drivers (9448, 9458, 9584) can sound pretty darn good on the right horn; its just that they aren't as good as the 1428. I have spoken to retired RCA engineers who felt the same way. Most folks will need to use a tweeter with any of these drivers. Interestingly, RCA never entered the spec wars, claiming response only to 8kHz. for their postwar systems.

I don't collect the RCA amps; I like to use low power SE DHT homebrew amps. Prices for the RCA amps have been rising steadily, though.

Marty
06-19-2005, 08:22 PM
[RCA]1400 series drivers made their debut in 1937. The MI-1432A (13V field) and MI-1444 (115V field) http://oswaldsmill.com/id29.html

Sadly, the 1400 series drivers were dropped by RCA after WWII, .

Steve:

I see they had good response down to 100 hz. What was their X'over freq on RCA system ?
What freq do you cross over your units at ?

Do you know where W.E. drivers were manufactured ?

How about the TA-4181 etc ? Made by Jensen as some say ?

Steve Schell
06-19-2005, 10:36 PM
Marty, the 1400 series prewar RCA compression drivers have a cone resonance of about 125Hz. This is due to the cone's medium mass and relatively compliant suspension. They can actually be listened to full range, but like most drivers they tend to "honk" if run down to resonance. RCA at first crossed them in at 250Hz., but later moved the crossover point up to 300Hz. to increase the power handling. All of those crossovers were 12dB/octave. These drivers perform with an effortless majesty in the lower midrange that must be experienced to be believed. They really deliver "big goose bump" vocals!

When RCA introduced their postwar radial horn systems the crossover point was moved to 500Hz. The cast aluminum 60 and 90 degree radial midrange horns are 500Hz. designs. The crossover remained 12dB/octave designs.

I have mostly run them over the years with passive 300Hz., 6dB/octave crossovers. When my partner Rich and I took our system to the Rocky Mountain Audio Fest, we demoed with a DEQX unit crossing at 250Hz. at 48dB/octave. This is what we plan to do in the future, partly because we can dial out the time delay of the differing horn path lengths this way.

I believe that the ERPI gear that was not outsourced was manufactured in a W.E. plant in New Jersey, possibly Murray Hill. To the best of my knowledge the early woofers used in the Wide Range systems were mostly 13 1/2" and 18" units OEMed by Jensen; these were special versions of their Auditorium Series drivers. Later, at least by the time of the Mirrophonic systems, W.E. was building their own 15" (TA-4151) and 18" (TA-4181) woofers. The Jensen-made drivers look quite different from those made by W.E. .

Marty
06-20-2005, 08:35 AM
Marty, the 1400 series prewar RCA compression drivers have a cone resonance of about 125Hz. This is due to the cone's medium mass and relatively compliant suspension. They can actually be listened to full range, but like most drivers they tend to "honk" if run down to resonance. RCA at first crossed them in at 250Hz., but later moved the crossover point up to 300Hz. to increase the power handling. All of those crossovers were 12dB/octave. These drivers perform with an effortless majesty in the lower midrange that must be experienced to be believed. They really deliver "big goose bump" vocals!

When RCA introduced their postwar radial horn systems the crossover point was moved to 500Hz. The cast aluminum 60 and 90 degree radial midrange horns are 500Hz. designs. The crossover remained 12dB/octave designs.

I have mostly run them over the years with passive 300Hz., 6dB/octave crossovers. When my partner Rich and I took our system to the Rocky Mountain Audio Fest, we demoed with a DEQX unit crossing at 250Hz. at 48dB/octave. This is what we plan to do in the future, partly because we can dial out the time delay of the differing horn path lengths this way.

I believe that the ERPI gear that was not outsourced was manufactured in a W.E. plant in New Jersey, possibly Murray Hill. To the best of my knowledge the early woofers used in the Wide Range systems were mostly 13 1/2" and 18" units OEMed by Jensen; these were special versions of their Auditorium Series drivers. Later, at least by the time of the Mirrophonic systems, W.E. was building their own 15" (TA-4151) and 18" (TA-4181) woofers. The Jensen-made drivers look quite different from those made by W.E. .


Great info, thanks. Did you use a supertweeter on demo system ? If so, which one ?

Steve Schell
06-20-2005, 10:35 AM
Marty, we didn't use tweeters in the demo system, but let our DS-1428 drivers provide the high frequencies. Funny thing, we didn't receive one complaint of weak highs the entire weekend. The DEQX did provide a bit of boost on top, but not more than 3 or 4dB.