Reconing D 140Fs

[basiklybass]

Along with my working D’s, I have several D140's with tattered cones or blown VC's. Over the years I have tried various remedies to get them doing what they should be doing. I just have never been able to bring myself to spend the big bucks on originals kits and I am kind of a tinkerer anyhow, never paid much or anything for the frames, not much to lose.

I have tried just replacing the cones without replacing the spiders and VC's, using an assortment of cones; JBL 2206, 130’s, aftermarkets, they work but fail at the joint sooner or later. I have tried aftermarket kits, they just don't sound anywhere near the original and most times are nowhere near as efficient, not loud enough for a 60 watt head. Many times the coils are round wire, or things are obviously poorly made. After a short time the cones on most of them have become brittle and cracked or the spiders have broken…not to mention melted VC’s.

I recently decided to try a RCF rebuild kit, $70.00 for 2 kits, figured it wasn't much to lose. They were the L15P200AK kits. I tried one, it dropped right in, everything seemed to fit, I glued it up and ran it for several hours at various frequencies, mostly around 20hz to break it in. (Love the Altec amps, they run all day at low, low frequencies) I just put it in a single 15 enclosure and plugged it into my 200S. Sounded great and loud. I then tried it connected to my Nemisis 250.....my kids yelled at me to turn it down....only a few pictures fell off the wall.

So far so good. I’ll keep you posted as to the longer term results, but for now, I am pleased with the results and with the price, $35.00 for a kit is a lot less than any other kit I have tried and besides, like I said, not much to lose except for some time…and a few picture frames. Plus, I can always send them out for a professional job.....but then I'd have to find more cabinets to put them in.

[Soundmasterg]

Thanks for the news! Ted Weber does the D130's but said he couldn't find a good cone for the D140's so he wouldn't do them. Maybe he might now!

[loudthud]

Where do you find the RCF kits ? I've been thinking of trying to re-cone speakers myself but never knew where to find the parts at reasonable prices.

[basiklybass]

Ebay, where else?

[made by hand]

had a couple of d-140's reconed with the jbl kits...ya..big money for the kits at the time...about 180 bucks...but ..who cares...they sounded like new...isn't that what we are all looking for..?? my 200s cabs can still blow the balls off the wallpaper.again, ..isn't that what we are all looking for ?? Bob

[basiklybass]

If one could get original kits for D140F's, I would consider it. But as they don't and haven't for many years...anything one does today is a compromise. The closest you can get, if lucky, or have the $260.00 plus, to buy them, is a kit for E & K 140’s, neither of which is the same as the original. Go back in the threads and you’ll see that many of the best reconers in the country these days will tell you the same thing, some won’t even do them because they do not “sound the same”.  All of the other D140F I have (5 in all including the one I just used the RCF kit on) have or had, fabric surrounds and corrugated cones, which from everything I have been able to discover, are not what the originals cones had. Of course, many of the things I have read are conflicting so unless Harvey can tell us, I will base my belief on what he has said and that is that the original cone was “slightly heavier”, was from the 150 woofer and the VC was copper. No mention of fabric surrounds. Follow this link to an interesting read on the history of the D130F in which he talks about the DXXXF series. The second link is to a page that has pictures of the 150’s which show a smooth cone, hence my belief that the original D140F’s had smooth cones. 

http://www.jt30.com/jt30page/micKspeakers/D130F-History.html

http://homepage.mac.com/ikecarumba/PhotoAlbum12.html

In an A-B test against the one D140F I have which looks to be original (paper surround, not fabric, smooth cone) the RCF kit holds it’s own. Dollar for dollar, I am pleased with the results. I have played through it for now some 3 or 4 hours and it still sounds great. I am running my 200S at about 5.

[Soundmasterg]

Thats great news! I asked Ted about those RCF kits you mentioned. He said he's working with a new supplier and will let me know more as he finds out. Hopefully he can come up with something that will work with the D140F for those of us who can't recone ourselves.

Loudthud, I've tried reconing myself and there is a bit of a learning curve but once you have that out of the way, and you've got some items to use as shims, then it should be possible for just about anyone to learn how to recone.

[EdBass]

If one could get original kits for D140F's, I would consider it. But as they don't and haven't for many years...anything one does today is a compromise. The closest you can get, if lucky, or have the $260.00 plus, to buy them, is a kit for E & K 140’s, neither of which is the same as the original. Go back in the threads and you’ll see that many of the best reconers in the country these days will tell you the same thing, some won’t even do them because they do not “sound the same”.  All of the other D140F I have (5 in all including the one I just used the RCF kit on) have or had, fabric surrounds and corrugated cones, which from everything I have been able to discover, are not what the originals cones had. Of course, many of the things I have read are conflicting so unless Harvey can tell us, I will base my belief on what he has said and that is that the original cone was “slightly heavier”, was from the 150 woofer and the VC was copper. No mention of fabric surrounds. Follow this link to an interesting read on the history of the D130F in which he talks about the DXXXF series. The second link is to a page that has pictures of the 150’s which show a smooth cone, hence my belief that the original D140F’s had smooth cones. 

http://www.jt30.com/jt30page/micKspeakers/D130F-History.html

http://homepage.mac.com/ikecarumba/PhotoAlbum12.html

In an A-B test against the one D140F I have which looks to be original (paper surround, not fabric, smooth cone) the RCF kit holds it’s own. Dollar for dollar, I am pleased with the results. I have played through it for now some 3 or 4 hours and it still sounds great. I am running my 200S at about 5.

I've accumulated a pretty extensive supply of vintage 15" drivers over the years, including several pairs of unmolested factory D140F's, and have pulled D130's from factory sealed early 60's JBL hi-fi cabinets.

The factory D140's have corrugated cones, and the 130's are smooth. Treated paper accordians on both.
It makes sense, doesn't it? The corrugation would stiffen the cone, giving less flex and therefore a less flabby low end response than a 130.

I would guess that the D140F you are A-B testing with either has a 130 or an aftermarket recone kit in it.

Not that it matters much, unless you are a stickler for authenticity.
If original is your bag, why waste time with reconers or "boutique" gurus? Talk to the guys at Jammin' Jersey in Northridge (as in "JBL"), CA. They definitely got it going on;
 http://www.jamminjersey.com/speakers.php?prod=jblspeaker
They don't use email, my guess is to keep idiots from wasting their time about things like this thread.
These guys are in business to actually sell drivers (not just to act knowledgable on a forum*), and they know their business .










*any similarities to particular persons on this forum is completely unintentional?

[basiklybass]

The shims supplied with the RCF kit were too large. I used the plastic wallet calendars you get from your insurance agent. Perfect, tight fit. The VC was solid through all the glueing.

I'll look forwards to Webers possible kit. I plan on having the speakers for a long time....so I know they'll fail at some point.

Point is at this point, I'm having fun and it amazes me the knowledge folks like SMG have...and willingly share. I just figured I share what I have found.....and learned.

Sometimes the hard way.

[basiklybass]

To Report:

A month later and the speaker is sounding better than before. I have pushed it hard (as hard as I can in my basement).....my kids just yell....but I'm louder. I have another one I am going to do and then both will go into my 215SPL cabinet.

Regarding the corrugated cones; I don't know what the D140F's originally came with, the JBL/Altec history site has an ad from early on that shows a ribbed cone. Harvey Gerhst says he used the 150 cones, which are smooth.  The 2) D130's I have are definite recones, both have fabric suspensions. The cones seem to be thinner than the 140 with the smooth cone. I’m not going to tear them apart to measure and weight….just seem to be.

While putting ribs/corrugations on a cone could indeed stiffen it, just making the cone thicker would do the same. So would treating the cone with some sort of paint or similar material. We used varnish in 1966 (on the old 12” speaker we ripped out of a radio we found on the curb). Lots of folks subscribe to the doping the cone school…for several reasons but in all cases, the cones would be heavier and I would think, stiffer when treated this way. Also with the ribs on most speakers, including the D’s, being concentric around the cone, one could speculate that they could act like a suspension component; the Altec BiFlex series used the same principle. If a cone is being driven so hard that it has to have stiffeners…why didn’t they put them radially instead of concentrically? Wouldn’t that have been better for stiffness? Or why not use a different material? Or glue thin strips of metal onto the back of the cone? Obviously manufacturing costs are a major consideration…in which case using a cone you already have makes the most sense. We’ll never know…but it is fun to play with and to think about.

In any case and whatever the original speakers were made with, I am very pleased with this RCF/JBL speaker marriage. I would recommend it to anyone.

[EdBass]

To Report:

A month later and the speaker is sounding better than before. I have pushed it hard (as hard as I can in my basement).....my kids just yell....but I'm louder. I have another one I am going to do and then both will go into my 215SPL cabinet.

That's good to know, the search for a good 140 recone is akin to the fabled search of Diogenes.

Regarding the corrugated cones; I don't know what the D140F's originally came with, the JBL/Altec history site has an ad from early on that shows a ribbed cone. Harvey Gerhst says he used the 150 cones, which are smooth.  The 2) D130's I have are definite recones, both have fabric suspensions. The cones seem to be thinner than the 140 with the smooth cone. I’m not going to tear them apart to measure and weight….just seem to be.

I'm not sure that the 130's are thinner, but considering the similarities of the motors on the the 130's and 140's, the 130's sound a little flabby in a bass application. I would have to contribute that to more cone flex, maybe softer suspension. Also, I'm not 100% sure of how the 130's were used/abused before I got ahold of them either.

While putting ribs/corrugations on a cone could indeed stiffen it, just making the cone thicker would do the same. So would treating the cone with some sort of paint or similar material. We used varnish in 1966 (on the old 12” speaker we ripped out of a radio we found on the curb). Lots of folks subscribe to the doping the cone school…for several reasons but in all cases, the cones would be heavier and I would think, stiffer when treated this way.

Obviously thicker material, either by doping or using thicker paper in the first place, would make for a stiffer cone. The issue is weight. In the fabled olden days, a 100 watt amp was huge. Every additional gram would cause a difference in mass that would need to be overcome by work force, which would decrease the sensitivity and response of the driver. In my opinion, the balance achieved by the factory D series JBL's is a unique, classic combination that is difficult to recreate. Is it the best? You got me, it has certainly worked for a lot of people for a long time.

Also with the ribs on most speakers, including the D’s, being concentric around the cone, one could speculate that they could act like a suspension component; the Altec BiFlex series used the same principle. If a cone is being driven so hard that it has to have stiffeners…why didn’t they put them radially instead of concentrically? Wouldn’t that have been better for stiffness? Or why not use a different material? Or glue thin strips of metal onto the back of the cone? Obviously manufacturing costs are a major consideration…in which case using a cone you already have makes the most sense. We’ll never know…but it is fun to play with and to think about.

I think the BiFlex has an actual suspension between two seperate angled cones rather than stiffening corregations, sort of an inexpensive version of the true coaxial 604 (or 605) drivers used in the famed "Big Red" studio monitors. The goal in both is to provide more of a full range capability than is possible with a conventional 15" cone transducer.
I believe I've seen radial corregations in car stereo subwoofers.
Several manufactures do use polymers or kevlar for their cones, mostly in hi-fi applications where cost isn't as much of a factor, and I'm a big fan of Hartke aluminum coned drivers. I think a lot of times Hartke cabinets get a bad rap, but I've used them for years because I like the sound they get. I don't really like compression drivers for a bass guitar application and those 10" aluminum cones get a nice snappy tone and still crank out a solid bottom, particularly with a big transistor power amp.

In any case and whatever the original speakers were made with, I am very pleased with this RCF/JBL speaker marriage. I would recommend it to anyone.

And... that's the most important thing!

[Soundmasterg]

An update to report.

Ted Weber has a clone of the D series JBL's on the way out (might be out already) using neodyminium magnets. The D140 clone will be the last one but when it does come out he should be able to recone JBL D140's and have a kit available. I think the timetable he was talking about would be mid to late June. This was from a post on his speakers bbs about 3 weeks ago, but I'm sure you could email him also if you wanted to know from the horse's mouth. This is great news for anyone who has old JBL D series speakers that need recones!

Greg

P.S. Ted said these new ones sound spot on to the old JBL's too, and of course weigh a lot less!

[basiklybass]

I look forward to Weber's continued good work in the speaker field. It is great that he can grow and actually produce such fine products in this day and age.

BiFlex speaker indeed do have a system designed to de-couple the larger cone area for higher frequencies....yet when I see the pressures put on a cone by the motor...I can't help but wonder if the further out from the VC you go, does the cone move in different ways or as a cohesive mass?  Do the ribs around the cone act in a in any way?

I like the Hartke's as well for what I think is their rigidity. And again, I agree that the D series just put all the right parts together at the right time....but the 130 flabby? I am not sure I understand what you are hearing to say that, SMG. It is likely that in most recent time, I have yet to drive them hard enough to hear it...I do not need more volume...I need more ability. While I have dreams of standing in front of a wall of Sunn's...my reality is much more like a dresser of Sunn's. And that is one great thing about music...we all hear music differently...and play even more so. And that knowledge can be shared like this. I know there are a lot of folks that know more about this stuff than I do. I learn a lot from this forum and others like it.

[Soundmasterg]

It was EDbass that said the D130 was flabby in a bass app, not me! I'd say the D140 is better in a bass app than the D130 for sure, but they used the D130 in Portaflexes as an option for years. I think they're fine. I might try one of these new Neo Weber clones when they're out as they sound promising. If you look on his site under the Neo series they're listed there.

Greg