The first real JBL 130 loudspeaker?
I am doing a little research out of curiosity to answer some questions I always had… and found your most excellent site, dudes.
Well, what I have had all these years is one JIM LANSING Signature MODEL (L in the circle) 130A 15" loudspeaker. S/N 12807. The name and serial number seem to date it around 1950. It has a paper--not Duralumin dust cap. The cone is in very good condition and well aged by now. I have never reconed it. Don't know if it was reconed before I got it. Back side of cone has stamps 180 20 (twice). Wait a minute--there is another stamp 180 200 crossed out in pencil. Factory part number change? Or offbrand recone? And even a 6 written in pencil. The QC stamp on frame appears to be 1B1 with a faint 2 below it in the circle. It has a cork baffle gasket. Unfortunately, condition is not mint. Some of the frame gray finish has pitting. The magnet cover dust may clean up with a toothbrush. I will be getting photos soon if you would like to see. I have found it quite good for vintage tube to 80's transistor amps for hifi and think it would be fine for PA if not abused.
Am I on the right track? Is it the original cone? Is it the same design and specs of a 50's D130? What are the specs? What rigs was it used in? Is it a really good guitar or bass driver? What guitar amp cab would be best? I might use it for an extension cab unit if the right match came along. Is it more of collector interest vs. a player?
Is it for sale? Isn't everything? Any information would be greatly appreciated. Then I could factually represent it on eBay or your marketplace or ???
Thanx a bunch, Martin W.
If you care to know… I originally bought it at a flea market for a ridiculously low price. I was an audio tech in the 80's who knew of the D130 series but surmised this "L" model 130A was a bargain consumer series or some cheap OEM special. We didn't do speaker work at Western Radio Lab in Mountain View CA. Mostly Macintosh & B&O warranties, all Century Stereo service and walkins. I started as the Dual turntable specialist because their changer mechanisms drove the other techs nuts. (Does anybody know Henry Pollack? He was my boss/mentor/expert on magnetic tape recording.) It was in a homemade corner cabinet with a University mid horn/xover and Jensen high horn/xover as yet unidentified. That may be another question to post later.
Needless to say, I bought it anyway. This unit has been used in my home as a 3-way center channel stereo speaker for the last, oh, twenty something years. I have gotten newer sound equipment--which will not need such a monster. So I no longer have a use for it. No, I will not sell my 1984 Altec Lansing 312 stereo speakers relegated to the game room. They make my Pioneer SX-650 sound great. Best setup was in another house suspended from the gabled ceiling angled down to ear level. They rode out the Loma Prieta earthquake no problema on 4 600 lb. nylon straps clipped to the baffles with my custom engineering. (The cabin survived with only 1" shift of the post foundation.) They would fall off the garden pot stands now but should survive except for grill damage. Just not suited to digital recordings through a Marantz Dolby 5.1 AV amp. Am happy with the Boston 965s for that. They work well for my corner placement environment and don't mind the odd geometry and R/A room characteristics. Some people hate the pointed screwy feet--but they are perfect for leveling one on a rock hearth and other on carpet.
BuBye
A little E/M + reflex cab tutorial please?
Thanx for answering the specs question, boputnam. One down and (too) many to go. And, of course, these answers raise new questions. This is fun to go down memory lane and back to school! My e/m theory never was that strong, and is rustier than ever, but let me venture into it anyway.
Cones are the same surface area. My 130A's magnet is a little weaker (Flux). This allows a lower res freq (Fs) from looser magnetic coupling maybe. Lower DC resistance and higher inductance... on the same diameter and length coil? Hmmmm. Coils must be wound much differently. Assuming the same throat gap and bobbin/coil clearances, I suppose Jim coulda put more turns of larger cross sectional area wire on. Would need a thinner bobbin (flimsy) or longer wrap to do that.
I'll take any extra efficiency I can get. Higher EFF tends to eliminate the longer-wrap coil theory as I think about it again... unless the throat is deeper. Too many factors involved to pick one efficiency contribution. No RMS power spec is OK. The least important one of the bunch until you put a system together.
WAY MORE DISPLACEMENT (Xmax) At first I thought "could the supension be that much softer?... because it's just the same CONE paper formed and not like foam or anything. I never trusted foamies when they first came out. Suspicions confirmed ten years later when friends' ARs started disintegrating! ... Aaaaaargh! My 312's finally cracked out their suspensions; boo hooooooo. Lasted longer than most, tho.) They just don't make 'em like they used to. Now I gotta start another thread. Anyway;
Duh! The displacement has to go into the magnet, too. So the 130A has much MUCH MORE THROAT DEPTH to allow for that... golf clap applause... LONGER WIRE WRAP on the coil. This is starting to make sense. That could account for the lower Qts I think (I could never understand "Q" until he appeared on Star Trek). I'll stick with this story for the moment.
Sounds like a D130 cone would be out of the question if the coil is that much unique. What are the chances Harmann (Kardboard, we used to call them back then) would still supply 130A cones? None to Huh? is what I would expect. I would buy a NOS 130A cone as a backup if somebody knows somebody who knows somebody.
The 130A as a bass guitar amp spikker seems like a marriage between Linda L. and J. Holmes, eh? Should have better transient attack vs. D130 as well. It will need to be ported much differently for any application. I'll guess a much thinner and longer reflex port path for bass guitar cab, like a slit extending back 3/4 of a typical cab depth? It's tempting to try closed back and front-- like my kickass Marshall 1912 guitar lead cab w/ a single 12" Celestion Sidewinder (150W!) ar, Ar, AR! That has awesome drive in the 200-500 Hz range. A JIM LANSING SIGNATURE on overdrive in the 60-200 Hz range would be truly unique. Vintage tone, Schmintage tone--I've got active pickups in my bass guitar. My low E string (42 Hz) is always too strong, anyway. Why fool around? Tune the cab to roar where the tones are most needed I say. Every musical instrument has a resonant hump somewhere. Even the earth is not flat, I've been told.
I KNOW YOU EXPERTS ARE OUT THERE! I have a little more knowledge and am even more dangerous now! Stop me (with design facts) before I go off the deep end! The 130A manufacturing curiosity started out strictly from a history buff. It now seems important for my cabinet design parameters if I can't go by the D130 book. 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.
Thank you in advance,
Martin W.
If you can't stand the attack, stay out of Jim's kitchen
I was editing online, Giskard, and you may have not seen the latest rev. Sorry, I will compose offline from now on. Thanx for chiming in. I am sure you are correct on the net magnet characteristics. What seems most different in the specs and would affect transient response is that much bigger peak displacement. A longer throat depth and a coil with more turns of bigger wire x-sect and consequently tighter spacing is what I was picturing as of the last thread rev. Your 1/3-more 'turns in the gap' calculation confirms that mental image for me.
Why did Jim revise the 130A-- producing less transient response and displacement in the D130? Was the 130A too difficult to manufacture? I'm surmising 130A coils were wound with less spacing and easier to goof. Or was the 130A less reliable? It seems such a coil would either dissipate more heat and need more ventilation--hence the rear vent port. Was the 130A first to to have rear venting? Did the theatres ask for mellowness? Was the crowd not ready to be attacked? Which did Leo Fender prefer?
More questions answered and five more posed. I had better stop geometrically expanding the questions for now.
This is wonderful, people. Where have you been all my life?
Martin W.
I was right in the first place!
Many thanx to all for the info. Current conclusion: this 130A IS the HOME VERSION sibling to the D130. The "Jim Lansing" label definitely dates it to the early period before Altec put a stop to that trademark infringement. So late 40's would be about right fer shure. The Univerity TC-30 mid driver w/ 4409 6x7-1/2 horn and Jensen high driver (a small unimportant mystery) are reasonable mates for it.
Net weight is 15 +/- 0.5 lb. as measured on my digital bath scale. It is the rounded back (die-cast?) magnet and a frame similar to the 1974 catalog photo except for not having the impregnated suspension. It has a pretty gold ring between the magnet and frame.
Power rating remains unknown. Something like 60-100W program or 20-40W RMS by reasonable standards now. You can only compare wattage ratings within one manufacturer using consistent test specs for the period anyway.
This makes it totally unsuitable for my wild ideas about forcing it to blast bass guitar tones. Oh well... The neighbors will sleep better if they only knew. 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?
Thank you all again,
Martin W.
Re: The first real JBL 130 loudspeaker?
Will the real D130 please stand up
Again I was told by an old timer (50s-60s) guitar player that the best was the D130 without a letter because of the narrower gap. Once they went to a letter the gap had been widened and the speaker had lost it's magic and great response. Perhaps the only exception was the D130F model whose F just designated it was made for Fender Amp use? This is not hard data but he knew his stuff and was of that time. I actually have some D130 and letter variants around perhaps a micrometer will answer the dilema?
Giskard posted references clarify all
Should have read his postings before above comments.
Basically from Harvey and Harry who worked for JBL during that time and were responsible for design and letter codes.
The D130 series all had similar cupper VC/frames etc but the A model was 8 ohms, the B model was 16 ohms. The F model made for Fender Amps had a wider VC gap at the top plate for less binding and only slightly reduced VC gauss and sensitivity but was more reliable and power tolerant. So the 130F is the only one that widened the VC gap to reliably play in the 100 Watt Fender Dual Showman. Some guitar players felt that change made the speaker lose some of it's "magic" although measured changes are minimal.
Thanks Giskard, we finally get the story right.