The first real JBL 130 loudspeaker?

[martinleewin]

I think I've got it now... The 130A rev1 came out at the same time as the D130 rev 1 with a welded magnet casing. Both models got the same sand cast magnet circa 1953. Altec's lawyers were as yet not griping about use of the Lansing name. Take a look at the Fender Bassman and Bandmaster photos and specs to see why rockers needed more than what was available;
http://www.ampwares.com/ffg/
I will take the designer Harvey Gerst's version over the Dick Dale story. No date for that but it's not my model anyway. Harvey widened the throat gap SPECIFICALLY for roadie mounting warpage allowance on all the F-suffix models. Other concurrent changes were mainly general updates.
The "goop" coated suspension originally for outdoor use became standard in other models. Thicker cone paper for stability under sound attack condition was applied to many high power designs. (Musicians are dangerous animals, you know. Roadies are just not to be trusted with anything delicate.)
The F-suffix models mixed & matched components for different music instrument apps and sizes. The aluminum coil D130F guitar model was probably the first to be introduced. 15" was really bigger than guitarists needed but it would stand the rockin' heat.
The D140F electric bass guitar model kept the 130A longer copper VC. All making it high power capacity, but a little less efficient, slower transient attack and less susceptible to mounting warpage.
My 130A sand cast magnet and frame is the same as the rev2 period D130. Its coil is rated 16 ohm on mine but is really 8 ohm if measured above its resonant frequency-- in its midband as later done. A more efficient, more responsive and more "musical" driver than all of the above as long as you don't torque or crank it toooo hard. My 130A rev2 would still work as is in a vintage Bassman or as a 2-way PA/home driver using a 1200-2400 Hz xover or 3-way using a 600-1200 Hz xover. The University N2A xover is wired in 700 Hz 16 ohm fashion.
It's reconable with a D kit, which would turn it into a D130 w/ Alum VC and Alum dust cap (adding some hertzes) for full range bass guitar or 2/3-way PA (or home) use.
Or a 2220 kit-equivalent to retain the sweeter copper voice coil sound and efficiency. The longer copper coil adds some moving mass. Paper weights may vary.
Now we know....
BTW-- I pulled the low driver out of that "Altec Lansing" 312. The flimsiest Harmann Kardboard 18 ga. frame they made (I hope) and a wimpy (10 oz. ?) ceramic magnet with "Super high-temperature pure copper voice coils". 22 ga. wire connecting "a multiple element dividing network to maintain precise frequency distribution" consisting of a hot-melt glued coil and a cap or two. I'd go for a Radio Shackish UPgrade, but even they don't sell a lightweight 12" woof woof any more. Tough to match efficient bargain drivers to suit these days. Can a shop glue a new surround on these?
Martin W.

[Steve Schell]

Hi group, interesting discussion. I'll add what I can.

Jim Lansing left Altec Lansing in late 1945 or early 1946. He intended to make a complete break from loudspeaker manufacturing, which he had done continuously since 1925. He bought an avocado ranch in San Marcos, CA and moved his family there. He had been interested in farming and breeding different types of avocados for some time.

Within weeks changes began to occur in the barn, as metal machining equipment began to arrive. Soon Jim had set up a full machine shop and was back into speaker manufacturing. It appears that he simply couldn't help himself, that he was driven to make speakers as an artist is driven to paint canvases.

His first product was the D-101 15" general purpose speaker. It looked much like the Altec 515 woofer that he had helped design and put into production only months before. It had a 3" voice coil and an aluminum dust dome to extend high frequency response.

Soon, while still building speakers in San Marcos, he introduced the D130 and D130A. These featured a shallow overall depth, shallow curved cone, 4" edgewound voice coils in a 12kilogauss flux field. He designed these for maximum sensitivity. The D130 had an aluminum dust dome and aluminum voice coil to extend highs. It could be used fullrange, or as a woofer in a two way system with crossover. The D130A used a copper voice coil and paper dustcap, and was intended for woofer duty.

Jim moved his "Lansing Sound Inc." operation to the Marquardt facility in Venice in 1947. He continued to produce the D-101, D130 and D130A (among others) in that location, but eventually stopped making the D-101. Next was a move along with Marquardt to Van Nuys in 1948. When Marquardt was sold in early 1949, the company was moved to Fletcher Drive in Los Angeles, where it remained for several years. So, these early JBL drivers can be dated pretty closely by the location mentioned on the decals. The earliest drivers will say "San Marcos, California" on their decals.

Jim Lansing stated his goals for his new company to Hal Cox sometime in the late 1940s, something to the effect that he had brought high quality sound to the movie theatre, now he wanted to bring it to people in the home." His new products did seem to be primarily intended for home use.

I have wondered about the similarity of Jim Lansing's products to the postwar Western Electric speakers such as the 728B and 756A. They do have much in common with the thin profiles, shallow ciurved cones, edgewound aluminum 4" voice coils. Whether there was some inspiration flowing in one direction or the other, or simply independent development along similar paths is hard to say at this point.

[martinleewin]

I read about the D101. Was not considering that as the first "real" JBL since it was an Altec design copy. My Jim Lansing Signature 130A was made in LA and it is from 1953 on, based on the cast magnet, to whatever. The serial numbers were sequential across all models, I was told, and would need a known year of manufacture with a close number to pin it down.
The Altec lawyers would have clamped down within a few years--one would suppose. Had assumed mid to late 50's would be the last Lansing labels. I saw a photo of an original owner's D130, dated 1965, which did not have the Lansing name. There was a reference I read somewhere that mentioned the label vendor's name. I don't have that much curiosity or need to establish the minimum age that way.
She is a well preserved example--and have the photos to show off now.
Made a nice avatar, too.
[IMG]ftp://[email protected]/jblsig86.jpg[/IMG]
Back, back, back.
[IMG]ftp://[email protected]/jblbak86.jpg[/IMG]
The business end.
[IMG]ftp://[email protected]/jblfrt86.jpg[/IMG]
Hairline cracks on the surround if you use a magnifier.
[IMG]ftp://[email protected]/jbledg86.jpg[/IMG]
The wrong stamp crossed out.
[IMG]ftp://[email protected]/1stamp86.jpg[/IMG]
Got the right stamp now--do it twice to be sure.
[IMG]ftp://[email protected]/2stamp86.jpg[/IMG]

Happy traaaaails to you, untiiiil we meet agaaaain,
Martin W.

[Earl K]

Hi Martin
I see this discussion thread about your speaker is now being used as a reference tool to help sell your speaker on eBay at 130a for sale . I don't have a problem with that. Now a warning; In all fairness to potential buyers, there's a 50 - 50 chance this particular woofer will not be able to be reconed, should it ever need that service .

This is because your vintage of speaker is likely to have a narrower gap than the present day recone kits will fit into. Factory rebuilding of the magnetic assembly would be required to rectify this condition .

Here's a jpg of this JBL published "narrow gap" alert info .

I'd steer your sale towards audiophiles who are less likely to blowup the speaker than "Spinal-Tap" inspired musicians .

regards <> Earl K

[4313B]

Thanks Earl! That's the old page I was looking for! Here's the new one... notice the differences?

[Earl K]

You're welcome !

Yes the differences,, well, the old page is more comprehensive. The new page with it's more streamlined info omits to mention that the older D131, D208, D216, D280, D123, & most importantly D130 (units) are all placed under suspicion of maybe having a narrow gapped top plate ( if the before mentioned conditions are present ) .


What I find the most intriguing to all this , is that as late as when JBL introduced the first 2205 and 2220 models, they still weren't committed to opening up those gaps for higher power handling. The time period of late 60's, early 70's shows them struggling to come to grips with the "new" market realities ( ie, letting the M.I. market drive some of the design ). Altec was slower to catch on to this mantra ( "Power to the People", etc. etc. etc. ), IME, and look what happened . As such, a real pivotal time period for both companies .

regards <> Earl K

[Mr. Widget]

Ok sleuths, I've got one for you.

Since widening the gap will lower the magnetic force, to maintain the same performance as earlier designs, larger magnets would be required. Is this why the pro variants went to the deeper return pot casting with the chamfered taper?

If you look at that well known ad for the L-300 with the cut away showing how the L-300 is virtually identical to the 4333 you will see a fine example of truth in advertising. In that photo as with real life production units, the woofers are different. I have never found an explanation as to why JBL would use the older round style casting on the 136A and the newer JBL Pro casting on the 2231A.

If this casting change was to accommodate a larger magnet to allow for a wider gap and hence greater power handling, then I would have expected the paper that Earl posted would have called attention to it.... any ideas?

[Earl K]

Hi Mr Widget

Yes, more magnet weight was needed to maintain flux level in wider gaps. A study of all the 1970s' catalogs show JBL ( simplistically ) started the decade with 11 lb magnetic assemblies ( for the typical pro woofer ) and ended the decade with 13 lb assemblies .

It seems that with the 12 lb assemblies of the mid-seventies ( like the 136a and the K120/130/140 ) the older / shallower pot could still be used and energize the wider gap.

A 136a can be reconed/ fitted with a newer 2235H kit. Those 12 lb "K" assemblies were housed in the shallow pot and were rated as 12000 gauss. And we know they had the larger gap for power handling. The 2231 had a 13lb assembly that required the deeper pot structure to house it. It too was rated at 12000 gauss in a similar gap width.

I can't reconcile the discrepancy between the 12 & 13 lb assemblies being housed in different pot casings and yet still having identical gauss levels. I will speculate that the larger assembly was built to provide more reserve power - like using bigger capacitors in a power supply to stiffen its' "torque" curve .

So ,,, the shallower / older pot style can't be used as a narrow gap clue ..

That's what I get from the publications.

regards <> Earl K

[martinleewin]

Hi guys. Remember me? the threadstarter. You have gone on ahead to reverse engineer magnetic design evolution of the early models by now without me, I see. You will need "hard evidence" to support your hypotheses. So why don't you break down a few examples to take a look? I can even suggest ways you should be able to put them back together for further electromagnetic/mechanical experimentation. This is a general guide...
0. remag to full strength; measure all the mechanical, electrical and free air acoustic parameters of the specimen for reference-- especially the maximum rear displacement & +/- unipolar transient step response while still intact.I want mechanical readings at many points across the cone +surround (foil targets and laser displacement meter plot here) and microphonic test results for this dynamic test
1. peel off the spider OD & remove the magnet assembly from the basket; measure gap gauss strength reading for reference
2. we must go where no (sane) person has gone before... we could:
a. cut it in half with a power saw-- but that would be too much work and was done before by 1975 marketing types, anyway, so...
b. I don't know how the magnet & pole piece are held together; probably press fitted because few good high-temp glues were made then; try heating outer & cooling inner pieces for removal; failing that...
c. score the section line on the return pot back flat side and break it open with a BIG cold chisel and sledgehammer while resting on an anvil-- repeat for top plate if necessary; leave magnet and pole piece intact
Don't laugh! This is basically how racing engine builders make precisely aligned crankshaft ends on their piston rods. The two halves will align perfectly upon reassembly. The leftover bits should not matter too much for your purposes and the weight loss can be measured and mathematically corrected unless it is in the gap area, right?
3. measure to profile the gap characteristics and component construction aspects in question
4. reassemble as appropriate-- hose clamp the return pot together at first; do not glue until later unless necessary
5. we should have demagged it substantially during disassembly. remagnetize in increments of gauss to plot the frequency and transient response as a function of gross gauss. You wanted to know that as a separate issue anyway.
6. present a paper with:
a. before & after shots
b. video of the disassembly process
c. video of the (fun) breaking process
d. video of critical reassembly process steps
e. CAD x-sect dwgs, tables & graphs of the measurements obtained and your experiment text with conclusions
7. submit the paper to this class for peer review of your work

We will award doctoral degrees in Lansingology for good work. I will expect credit as a co-author (or should that be co-conspirator?) as well and will volunteer for Creative Director for the video release. Royalties and distribution rights to be negotiated.
All we need are specimens, an A/V crew and Lansingology doctoral candidates. Who wants to volunteer?

Martin W.

[boputnam]

I see this discussion thread about your speaker is now being used as a reference tool to help sell your speaker on eBay. ... I don't have a problem with that.

Nice one, Earl!

But it would've been proper to have that disclosed in the first post, and maybe start the thread in "Marketplace".

Another eBay'er - sheeze!

The history and engineering contributions from the knowing have been worthwhile, indeed.

[martinleewin]

From this and several other informative sites I have gained knowledge of speaker selection and tuning to use in my restoration and repair business. If you want to start another thread for the current discussions, OK. I can not change the ebay listing now. My intent for referencing this thread was for ebayers to see how and where the facts were derived. The Lansing Heritage site was the best place to gain the info on this little known model. All other relevant data links were included, too.

I have a genuine interest in the design, performance and history of audio gear, among other things. I do truly appreciate the information from this site and forum members. Anybody who feels I was not up front about the intentions for this piece was not reading carefully. The message was early and clear;

POST #2; "BTW- Now you can see I'm not some pawn shop reseller who slaps a $$$ label on everything old and dusty. I find the ultimate app for good old stuff or sell to someone who does."
We were still determining the real specs and applications at this point...

POST #5; "Look for an ebay item something to the tune of 'vintage 15" JBL University Jensen speaker set NR' in the next week or so. Unless I take up an offer in the meantime. I don't see much demand for this series on your marketplace. So
that's a rap for this topic... unless a Lansing collector needs one?"
That was a chance for forum members to buy before the rest of the world. And to look for it if interested. This is a personal item not connected with my vintage audio business. Another plug? Each reader can decide for themselves.

Was my ebay listing not factual and well researched? I like all buyers to understand what an item really is for a successful deal. I notice many here keep their eyes on the world's biggest marketplace. Maybe some of you buy and sell there, too.

The thread continued into later driver design evolutions and here we are. I have learned a lot more about speaker technology than expected. Thanks again for the insights.

Best Regards,
Martin W.
Wizard Labs

[Earl K]

Hi Martin

I thought it was pretty plain from your first posting that your speaker was headed to eBay. Obviously that didn't dampen my choice to talk about this class of woofer. As I said before , no problem here as far as conflicts go .

I like the idea of trying to get a fix ( to paraphrase ) on what the actual gap widths were - way back when . Most of your suggestions would be too difficult/costly for one person to implement but an internet group could accomplish similar results by collecting data over a period of time and creating an adhoc database. Understanding JBLs evolution of gap widths , cone weights and magnet strengths would benifit all users / resellers of these woofers. I'd love to know about when JBL started to add weight to the cone of this driver. As Paul Joppa reported in , it seems a certain era of this speaker had @ 60 gram cones vs 80. This is valuable info for those who place a premium on "quickness" in response vs LF extension . The tighter gap, with a lighter cone will create a woofer that should give good emphatic midbass performance ,,, see the E 145 discussion for more about this . This sort of sound can be very addicting for those who put a premium on midbass quickness.

So - If other readers would take note that for future recones of D-130(s) & 130a speakers to :

(1) take some pictures ( for the records ) of the appropriate distinguishing characteristics ( as mentioned in the 2 JBL notices that Giskard & I posted ) for these woofers

(2) have a reconer make & record actual gap widths before fitting or not fitting a replacement cone.

(3) record the serial number of unit.

(4) if the owner has a pair - make some notes about any apparent performance differences ( especially if the 2 units look to be of different vintages ).

(5) make some TS measuremnts. Off the top of my head I can't provide a link to a site that has sowtware one can download to help in this,,, apparently its out there. Maybe someoone else remembers where this site is .


regards <> Earl K

[boputnam]

I am doing a little research out of curiosity to answer some questions I always had… and found your most excellent site, dudes.

Hey, Martin Wizard Labs...

That quote starts your first posting. I nowhere in the first posting can find any reference to your intention to sell the mythical 130, and was interested in the query. Hell, I was one of the first out of the box to try and "solve the riddle" - you even got the post from rare ol' Don McRitchie tossed in. But I backed away after the confusions on whether this was research or promote. In the end, it appears mostly research - odd, since the item is being eBay'ed. I'm perplexed, but it seemed fruitless to offer much more at this point - wait for the buyer to surface and then give 'em all the dry powder.

My view is at the outset you should have posted in "Marketplace" clearly stating:

dudes, I found your most excellent site and am eBay'ing a seemingly rare 130 transducer that I'd like to know the history of. Can anyone help?

That is full disclosure.

And it would have gotten nearly the same attention from the knowledgable, for sure.

Good luck!