The American Speaker Project, now and then...

@hifitown Another question more on topic! Can you share your thoughts about the 50's 12" Jensen P12* series? Are there significant diffefences between the P, N, Q models etc.? I'm curious as you mentioned in another thread that the N model could possibly be a good fit with a KS12027 replica horn, which might well interest others here! Finally, several users here seem very happy with the 15" family (P15LL?) in a hybrid Altec 802/32 2 way, so just wondered if the 12" speakers might also be a worthwhile option. And I guess if you have any thoughts about particular 8", 10" or 15" models, they would be gladly received too! Sorry for the barrage of questions.
 
Hi jt23. I wrote a mashup for the Haven, with photos, as it turned out the message ran over 10,000 characters.... here are a few clippings...


In regards to 8" ... Bigger area need for woofer duty... If efficient reproduction of real lows are needed…. bigger is better (no, not saying to go get EV 30W’s, that’s a whole ‘nother thing guys!). But, using smaller than 15” drivers gets more “pistonic” and removes detail / adds distortion. Since small drivers have to go in and out more to move the air, the magnets have to be bigger and more powerful too, or they get terribly flubby.
Altec discovered this jig in the 1960s, and promptly “upgraded” their entire line of rolled paper edge speakers to disco-fantastic accordian edges. Hey, they are still great speakers — but it is a different sound, and inevitably some detail gets lost in that chest pounding bass friendly design.


Part one of a mashup — for HiFiHaven members:

I will be dipping into some of this writing for a refreshed website, when I get to listing more inventory for sale someday soon. You guys read up first… and don’t smack too hard if I repeat myself. Solder fumes and the sweet smell of recently cured shellac may be getting to me. There was too much said below, so surely some mistakes were made — I’ll fix those errors later perhaps!

Early fully acknowledges, this is a public forum — I would like to request of anyone wishing to grab snippets (of this horribly crafted. non-scientific op-ed...) for auction site or forum sales, please paraphrase, and/or just email/ message for a quick permission request to use….. This is not so much copyright concern as it is more to keep me from endorsing any particular cruderific or sketchy merchandise I might wish no association with… :-) !!

Where possible, I am going to insert to a link to an example, of speakers I have sold or am selling, (and or likely have more of, so anybody, feel free to inquire).

WECo’s challenge:

It’s quite possible — (thank you collector market) — to discount one of the major reasons these components cost so much. It all goes back the raw, unrivaled sound quality that many of WE’s best components had..(ie the 713C, 755, 728 etc). You can hear how good these are right on the bench, forget about the horn.

This quality often led the guys at Bell Labs / WECO to achieve the impossible — even when breaking rules, in bland in-wall enclosures… Despite totally conventional cabinet design, Western’s boxes benefitted from over the top 1950s materials, like hide glues and natural resin varnish coatings… which actually helped allot as well)

Until we discover (or build) a driver like the 713C (or heck, even an original 1940 Lansing 901) — it’s going to be hard to build a totally satisfying 2 way WE757 (aka outright replica),.
So then, It makes sense to ask — hey, why do I need a WE728 as a woofer, to compliment the
KS12027, if it’s going to be a 3 way……. Good question. I agree — you probably don’t.

WOOFERS:
The area of woofers (very brief, not very well organized overview as follows) :

Going to cover three regions (this is part 1, if request can post the other section):
Note: While my first loving recommendations are “Fast woofers” for low needed watts and crisp airy detail… this does not forgo the very rational and needful uses for the other classifications — **especially if you can find watt-sipping, all paper “real woofers” for OB, see “below’)

“Fast” woofers:
The bass you hear at acoustic events, Jazz, live rock, vocals, acoustic — where most of the information lays —

That’s some LF, upper-mid bass LF. and throaty low-end mids… not deep sub-sonics, or punchy / chest pounding stuff.
That’s all the WE systems tried to cover for the most part.
These, so called “fast” woofers show off with a finger tap — emitting a nice, larger than life, springy thump… (evident in their tests, of higher cone resonance if one bothers with T/S measurements)
Because they are light, they conversely don’t need the huge magnets, you’d think would be prerequisite to making “realistic” bass” — that’s not the case. Light, all paper woofers are good at production realistic LF.

Woofers that excel here are almost all going to be 100% paper, with maybe some goop to calm things down, but no cambric or cloth.
Altec stopped making them mostly by the early 1960s, wih the last of the green, B and some C series stuff.
“Fast” woofers should be high sensitivity if possible.

Examples of fast woofers,

Altec’s early 16 and 20 ohm stuff with gold decals that say “Hollywood”.
These are actually both "fast" and "real" -- so they are good, and now expensive.
803 B Hollywood with phenolic spyder damper (not to be confused with 803C)
803C “gooped accordian edge” with early clamp ring 1950s more of a “hybrid” see below, but will leave it here for now…
http://www.hifitown.com/pictures/rcvrpraltec803a3a.jpg
603 full range (with a weird static horn) these are actually Really good, and are skyrocketing in price
Altec 515 hollywood with phenolic spyder/damper (very heavy cone so walks the line on purpose…)

Stephens Trusonic
12 and 15” 1940s and 50s.
Many fascinating full range drivers, 12 an 15" that extend way, way past the 728.
A good topic for another time.
Later stuff went Cambric (see below)

“220”
Jensen “F” series, 12 & 15” late 1940s field coil…
Jensen “A” series” most common the A12… an undersung, but really nicely made 1940s/50s field coil.. 12” full — range, bass capable speaker…. early phenolic spyder, and no dustcap
Field coil was high voltage. I know on only a few audiophiles who use this nice old Jensen, and not sure why it’s still a sleeper
Jensen P series, alnico all types. Some versions sound better than others, late 1940s with heavy sandcast mags, through late 1950s…
Jensen P series, these were made from late 1940s onward, and used in a variety of rather famous classic WE, Westrex, Motiograph, Simplex and others….

The musical instrument version “N’s” and “R’s are KILLER — amazing)
http://www.hifitown.com/pictures/rcvrprjensenp12n4a.jpg
http://www.hifitown.com/pictures/rcvrprjensenp12n4b.jpg

I am afraid you have to go by looks as terrible as that may be.

The P15 (not LL) is really famous as it’s 16ohm WECO KS cousin resides in the Western Electric 753 system, stock — early paper spyder make these very delicate, but nice sounding woof’s.
Console and amp speakers, not to be overlooked:
these woofers were lightweight, and good, and some of them had wrapped cones…
Jensen P15R and P15Q (tiny horseshoe alnico) (one of our fav’s with the 808 horn)
“C” series, C12 and C15
By the 1960s and 70s they made some really cheap stuff that was still very good, so if you want good sound on the cheap, look here.

“232”
Yes, 232 is Magnavox, yes they did make their own speakers. And in the early days they made some damn fine 12 and 15” LF capable all paper speakers. The early Field coil ones are getting expensive,
Many were made for “real bass” (see below.), with felted over or stoppered dust caps for Pipe Organs….
There are also some direct sandcast alnico comparisons the the Jensen p12N… and dare I say possibly even better!
Look for them!

to be continued....
 
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Part 2:
12 & 15" Woofer Opinions, HiFiTown


Some of the 1940s General Electric, (Electronics
Park era) bubble shape frame speakers are out of this world. Most are great.
They cover a similar similar range as WE728, but do not have the low cone resonance.
(This comment does not include the 1960s cambric / flexair version.)

“285”
Rola, another early all paper maker from Chi-Town — made some good stuff for the musical instrument co. If you are looking for “real” or “hybrid” speakers that are all paper, look at some of these carefully.
In general, Rola speakers are a mixed bag… some are OK, and some are 5 star outstanding…. not near as consistent as the Jensens… a reason why the Brand really sleeps.

RCA
9443 15” field coil
9449 15” PM
and Many 12” types.
Older is better.

And lots of others,

See EIA codes… these include 328 (Utah), (270) Quam and (465) Oxford

REAL WOOFERS
Born of the 1950s HiFi craze, robe wearing, pipe smoking, liquor tasting, really manly men, discovered they needed actual woofers.


By “actual”, I mean, a speaker made to make LF, and only LF. The cones tend to be heavy, magnets are larger, and most importantly, the cone resonance is nice and low. For this reason, in some cases, we enjoy running them full range, cross-overless, because they simply can’t reach into the mids…
These actual woofers don’t know what fast is. They are slow moving air pushers.

The older they are, the less the cones moved in and out.
High excursion later models meant deeper, “whompas” bass, as Walt liked to describe it.
Whompas is enjoyable, for instance with authentic 1970s recordings with electronica etc.

Bozak:
Bozak B199— sorry to all.. I don’t see these as WECO 728 replacements. They do have low cone resonance, but they also move very slowly …making the class of an early “real” woofer (the paper really did have wool!). They’re good “real woofers” that can perform with low loads and maybe OB in some cases.
Rudy Bozak worked for Western Electric for a stint, and then an interesting company called Cinaudigraph. While there, he worked on some of the earliest super woofers, up to 24" (before the Hartley and the EV by decades). He then shot off on his own after WWII. His design philosophies were well researched, legit, and novel. The materials, ahead of their time. The systems, power hungry, well balanced and ready to rock the house. Ultimately, Bozak speakers are not usually sensitive enough to keep up in real miliwatt tube horn systems, but can be integrated in moderately stout to setups, to good success. Old Rudy did claim they were supremely efficient, but not sensitive, a perhaps correct redressing of terms. They do have uses, and allot of the early parts really can sound very, very good. The parts are generally very undervalued and getting less common, so watch for a price rise over time as new-found and rediscovered uses emerge. On these, I take notice on the early 1950s B series, most of which was a thick woolen paper -- this includes the 12", which often mounted in the space of a 15, with a nifty adapter ring... this ring setup was also used to form a crossbar to hold the tweeters, in coaxial arrangements.
By the 1960s, The B series 6 and 8" midrange drivers, as well as tweeters, had gone aluminum clad, high design. These parts are less sensitive than the older all paper, versions, which also sound different. Premiums are paid for the early paper stuff. Bozak systems are also well known for more-complicated-than-normal crossovers, which are no basic butterworth -- and are more of a complicated 6db per octave charade -- they have a cult following, as well.

— EV 12W & 15 “W” and “WK” (Klipsch)
Early EV was spawned by engineering at the west coast Stephens Trusonic camp.
Old Electrovoice was nicely made stuff, and possessed real hifi pedigree. It’s most certainly way undervalued at present day.

— University C15 (these are a odd beast, and have a cult following because of the dual voice coils) — They are cheap, overbuilt and sound pretty good, honestly one of University’s best products… As good as Altec, JBL or RCA? Looks / build, yes. Sound…maybe — maybe not — depends on your genius.

— Altec 416, 414’s, late model 515 C,D,E
All excellent woofers, with a nice balance of speed and excursion to please all.
An undersung version of the 414, we really liked was the last — 414 16C

— Jensen P15LL (there were 3 versions of this “real woofer”, all called P15LL…
the pretty one was used in the Jensen TP 100, TP 200 Triplex, as well as big RS-100 Imperials..
The plain one is just as good, and was used famously in the good Leslie organ speaker…

the Imperial version:
http://www.hifitown.com/pictures/jensenp15ll_imperiala.jpg
These are really good. and at present 2020 prices, a pretty good value.
The heavy paper makes these slow (not to confuse with P15 of F15 original)

By the late, late 1950s, Stereophonically intoxicated, space-faring man discovered the insane concept of hermetically sealed boxes…aka the supposed be-all, end-all of HiFi perfection (Hey one is at the Smithsonian, that settles it, right?, bah hahaha :-)

This lead to air suspension woofers:
— The excellent, originally AR1 and (early) AR3 12”.
This beefy, engorged, doped and rubber laden monstrosity worked very well for what it was.
On the first gen, no foam on these, just paper and cloth.
This speaker, went through more revisions than can be written here.
Suffice to say, the first version is the coolest, which was all paper, and a heavy black fabric edge.
Out of the sealed box, these have serious uses— in the deep, deep LF region.... they are not any less efficient or sensitive than the B199, and the midrange rolloff is SUPER STEEP, making it one of the woofiest-woofers you’ll ever encounter.
If memory serves, it’s also 16ohm.
Early Janzen systems also used the AR1 version (and of course AR1W)
It’s the real deal in this category.

— Jensen Flexair series, made for sealed enclosures and other heavy reflex cabinets like the famously donned in Frazier’s brilliant little Dixelander. Jensen Flexair speakers have a following and their uses. They are not super sensitive speakers.

Hybrid... aka "Jack of all Woofer - Speakers"
I am mixing things up here, because to be fair some of these below were never intended to be used in open baffle setups… leaving them in the list because allot of value to be had,, these are Jack-of-all-Trades, tube era speakers that try do it all: Look for 12 and especially 15” speakers that have blocked over vents on the dust cap

Altec Biflex series 412 and 415
Not sure why these are not more popular. They’re pretty good for allot of needs.
http://www.hifitown.com/pictures/rcvrpraltec412b8c.jpg

Altec 420 — these were the ill fated of Altec’s pro 15” line. A ruinous product that sent their languishing Musical Instrument division into an embarrassing tailspin. The 420 was Altec’s answer to the JBL D130, but it, like allot of Altec was just too delicate… so yeah, they cooked on silicon powered Deep Purple riffs — oops.
For HiFi, the 420 should be well enough suited, but so far, few reports in.
http://www.hifitown.com/pictures/rcvrpraltec420a3a.jpg
http://www.hifitown.com/pictures/rcvrpraltec420a3b.jpg

JBL D130’s and musical Instrument variants.
A masterpiece do-all speaker that we never used around here, .. unless it was in a spectacular JBL enclosure of one from or another. As with Altec, the older-is-better rule applies.

— The Rola 15” all paper (this speaker was used originally for pipe organs!
http://www.hifitown.com/pictures/rcvrprrolawoofersa.jpg
http://www.hifitown.com/pictures/rcvrprrolawoofersc.jpg
These ROLA's proved popular for nice, speedy low bass on open baffle…

— the EV’s, SP 12 (the 12W rocking a sub cone to make it full range)
— Many of the Jensens… look for felted over vent caps.
And many more....
The end for now.
 
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Audionut

Next Round Is On Me
Thanks for sharing your wealth of knowledge, you have me geeking out over here. 🤓

I am looking forward to more great reads!
 
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Altec’s early 16 and 20 ohm stuff with gold decals that say “Hollywood”.
These are actually both "fast" and "real" -- so they are good, and now expensive.
803 B Hollywood with phenolic spyder damper (not to be confused with 803C)
803C “gooped accordian edge” with early clamp ring 1950s more of a “hybrid” see below, but will leave it here for now…
http://www.hifitown.com/pictures/rcvrpraltec803a3a.jpg
Not wanting to be too nitpicky, just wanted to add my $.02 about some of the Altec woofers. I think Early has maybe transposed the Altec alphabet a little bit. I believe the early 803 was the 803"A", not "B". The first ones were gray paint, 12 ohms and had a rolled paper surround without doping. Later 803A (late 1950's) were 16 ohms, green paint, and had a doped rolled paper surround. These are the woofers shown in Early's photo link, and the same type I have in my Iconic repros. All 803A I've seen have the clamp ring holding the outer perimeter of the cone. IME I've not seen any 803 with a phenolic spyder/voice coil support. I've only seen that on the first 515's, but I'm always interested to learn something new. 803B (early 1960's?) were the first ones to get the gooped accordion surround, some of them had red fabric, some black. AFAIK, an 803B is pretty much the same as a 416A. And I've never seen an 803C--I think before they got to "C", they changed the name to 416.

Really appreciate all the information in this thread--it's a good read. Keep it up!
 

MrEd

Senior Nobody
After re reading your run down on woofers I would like to query your thoughts about a pair of Rola's I plan on using soon.
Field coil 12" from 1950 from organ cabinets.
20200925_200821.jpg20200925_200756.jpg
 
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Not wanting to be too nitpicky, just wanted to add my $.02 about some of the Altec woofers. I think Early has maybe transposed the Altec alphabet a little bit. I believe the early 803 was the 803"A", not "B". The first ones were gray paint, 12 ohms and had a rolled paper surround without doping. Later 803A (late 1950's) were 16 ohms, green paint, and had a doped rolled paper surround. These are the woofers shown in Early's photo link, and the same type I have in my Iconic repros. All 803A I've seen have the clamp ring holding the outer perimeter of the cone. IME I've not seen any 803 with a phenolic spyder/voice coil support. I've only seen that on the first 515's, but I'm always interested to learn something new. 803B (early 1960's?) were the first ones to get the gooped accordion surround, some of them had red fabric, some black. AFAIK, an 803B is pretty much the same as a 416A. And I've never seen an 803C--I think before they got to "C", they changed the name to 416.

Really appreciate all the information in this thread--it's a good read. Keep it up!
Thanks, and yes, I surely do have some of this mixed up!
Yep, above was written speedily by memory. Unless somebody's buying some , I rarely dig through inventory. It can be decades before I look sometimes..... your corrections are sounding spot-on. This is a travesty, because 803's were something Walt regularly recommended (and still do) to folks in lieu of 515's. It was one of our more-favorite woofers!

The only thing that gives me pause, is I did believe the first version, of the 803 had a RWB label, and it should have had a phenolic spyder... then again, on this I may well be wrong.

The 803 with red fabric were utilized in the excellent Altec Laguna, (2) of them to a 511 horn. That was a well balanced system, proving you can make beauty with the later often bashed, cast horns.
The 803's with red surround were allot like 416's -- but I think we still liked them (803's) a tad better. They are rather rare.
416's (especially the Z's) often suffered quality problems, and some of them got a bit hard on the edges, needed chemicals to get flexible again. Otherwise, though, they were good too! My main hangup with the 416's is the prices sometimes... they were used OEM in so many expensive systems -- folks seek them out, when 803's should be getting a closer look. Then again, 803's are going up as well, by now.
 
The only thing that gives me pause, is I did believe the first version, of the 803 had a RWB label, and it should have had a phenolic spyder... then again, on this I may well be wrong.
Could be they did have phenolic--I'd love to find a pair if so. I've never had opportunity to look closely at an 803 with a RWB Hollywood label (not sure I've ever seen one at all, come to think of it). Would that be the really early kinda dark blue smooth paint ones? I've seen wrinkle gray 803A's (early to mid 1950's?) that had accordion fabric spyders that looked original.

Either way, interesting information on a very good woofer. Mine are part of a set of 802C, H811, N800D, 803A that were all bought new together in 1958 (have the receipt) and used in a built-in home system. Hadn't seen the light of day until I pulled them out. I've sold the H811's and have set the N800D aside in favor of my own custom crossovers. I use the 803A in a clone of the original "Iconic" cabinet, and the 802C with genuine Altec H808 tar-filled horns. Couldn't be happier with the sound.
 
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Can you elaborate on this statement? Does is also apply to The 414-8c as well?
Hi Guys, sorry for any delays in reply -- it's been a buzzing spring -- slow and steady wins the race I suppose!

Yes-- Good question on these! Yes I called them undersung, because at least in our experience – – they rarely came in....but the Japanese cats love'd em -- and they know... As the 70s and 80s grew to a close, Altec sold fewer and fewer products – – too many other companies stealing their business....At any rate, they still had a good core engineering crew I suppose and did some pretty interesting tweaks and developments late in the game. ((I've got to say one of the most unusual things I ever saw was the 594 Western Electric copy based on a two 288 G body. -- )) I digress!

Back on topic, yes this would be regarding the very last (as far as I know) alnico type of Wolfer and Altec made in both 12 and 15 inch versions. These back covers are made out of a cast or machined solid metal and painted with a heavy textured finish – – they look like inverted pie pans actually. This would lead what to believe that they are a ferromagnet however they are not! I should dig up the literature on these as I think I have an original. Anyway, if you were going to go with one of the later design woofers that makes more bass via extra excursion – – these are really excellent versions!

The only differences I can think of with the "8C" variant would be relatively unimportant 8ohm impedance reading as well as maybe a ceramic magnet? You have to be careful here because there were different types of magnets manufactured... some were Alnico in the 1970s like described above, and then towards the 1980s they switched to a ferrite rubber trim covered magnet... (old-timers who knew more about speakers than I ever will), used to jokingly referred to these Ferrites as "mud magnets"

Now the debate can rage on as to "how much" better, field coil/electromagnet is vs PM, alnicoV, And lastly the euro. termed "ferrite"... or what we would call ceramic magnets. The glaring differences, of course.... the ceramic magnets are very bad at leakage and stick to everything. Much better to have all the strength going to the gap... but Ferrite does not go weak over time...that's cool.... So yes, a sign of cheaper material – – this does not translate into a worse sound necessarily. I can't tell you the number of times I've heard better sounding ceramic magnet speakers too many to note. This is because most "responsible" component for sound is the diaphragm or in this case the paper con/voice coil....

Magnets strength is critical to detail reproduction and dampening of course, but too much can at very least, unneeded.... And in the case of some of these really large Altec drivers like the 291 or 515.... it really an be almost excessive. That's why it's over-the-top to have some of these drivers re-magnetized when they were already too powerful!!

One of the future experiments on my bucket list will be to power up some high voltage field coil Jensen 12's, with a low power DC at around 30 V – – I expect to get quite good sound from them so they will be underdamped…
 
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Same here.
Many thanks for this gem of a thread.
Hey guys, that's great. It really is nice to chat and catch up with old friends and customers. And I hope that it is somewhat helpful and not too full of typos – – I definitely write them too quickly and there are most likely mistakes --- so you guys feel free to correct!
 
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The only differences I can think of with the "8C" variant would be relatively unimportant 8ohm impedance reading as well as maybe a ceramic magnet?
I own a pair of the 414-8C. They are as I believe you described: they have a one-piece cast return pot that has a stepped shape. This pot is painted a textured black along with the rest of the frame. The frame is the square edge cast frame. Magnets are alnico. The 414-8C only mounts from the front.

When compared side by side with a 414A, the cone appears to be slightly more coarsely textured and perhaps slightly heavier. Altec rated them 3dB less than the 414A. I’ve seen factory response curves for both drivers. The 414A has a classic rising response and more smoothly extended top end. The midrange response is a bit greater than the mid bass. The 414-8B response is flatter but does not roll off as smoothly nor as high. It appears the later driver response is knocked down in the midrange a bit to better match the mid bass.

In another thread, a user simulated the Altec 614 and 9849 enclosure response. He noted the 614, with its 2” x 7” x 3/4” simple port showed a “pleasant” bass hump around 55hz that seemed to work well with the response of the 414A. The later 9849 cabinet of the same dimensions had two tuned ports of 3” x 6”. These ports were of the same area of the 614 port, but 6” deep rather than 3/4” deep. The resulting response was much flatter than the 614, with extended but not exaggerated bass. This response would seem to work well with the 414-8D, extending bass response without the mid bass emphasis. The response looks a lot more like a sealed box than a vented enclosure. I think the response was tailored for near-boundary location in smaller control rooms.
 
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