I have to admit I'm a little biased, as we own at least 18 of them throughout the family.....[/QUOTE]
I am only the second
I have to admit I'm a little biased, as we own at least 18 of them throughout the family.....[/QUOTE]
I am only the second
Originally Posted by Docspeakers
Well to be a little more specific,has anyone here owned/heard them? How do they stack up to Tannoys? Are the built in crossovers worthy? Any info really.
Although some manufacturers tried to represent speakers with whizzer cones as a kind of two-way I don't the "co-axial" description is meaningful unless you are talking about two separate drivers/motors mounted on axis in a single frame. So I wouldn't consider JBL's "extended range" drivers like the LE8s to be coaxials.
JBL only really offered two coaxials for home hi-fi use.
JBL introduced their 14 inch LE14C around 1962 as a "composite transducer" ("C" for "composite"?):
http://www.lansingheritage.org/image.../page08-09.jpg
This was the first use of the 14 inch basket frame.
Notice that the LE14A is not in the 1962 catalog and made it's appearance later than the LE14C. The LE20 was introduced around the same time, perhaps derived from the design of the LE14C?
The higher compliance suspension allowed this speaker to function well in a smaller cabinet (as small as 2 cubic ft.) ,a size much more suitable for the home environment than a cabinet with a 604 in it. Cabinet size, and the ease of placement (or difficulty) became more import when the LE14C was introduced because in the early 60s stereo was catching on.
The LE14C was still in the catalog in 1976, and the non-coaxial version (S12 system) lasted until 1979 as the LE14H/LE21H combination.
A highly evolved version of the 14 inch driver, the LE14H-3, is being used in JBL's new high-end Array home system.
http://www.jbl.com/array_series/specs.aspx
The 12 inch LE12C composite transducer appeared in the 1967 JBL catalog, using an LE20 derived tweeter crossed over at 3K, and was still in the components catalog as of 1976.
http://www.lansingheritage.org/image...full-range.jpg
Much later, in the mid to late 90s, JBL introduced the 12 inch 2142H with a coaxial dome tweeter crossed over at 3K, and the higher powered 12 inch 2152H and 15 inch 2155H that used a 2416 compression driver on bi-radial horn. The 2152H crossed over to the horn at 1500Hz while 2155H with a larger horn crossed over at 1200Hz
http://www.lansingheritage.org/image...pro/page35.jpg
These were intended for installed sound systems, not the home hi-fi customer or studio monitoring:
"In response to consultant and contractor requests, the
JBL 2152H was designed to perform well in the most
commonly-specified utility metal enclosure and baffle
combinations, despite the generally detrimental acoustical
properties of those enclosures. Custom-build boxes will
usually result in better peformance characteristics than
those published here."
They offer a high-power, wide-bandwith speaker in a single unit that would install as simply as a cheap single driver.
I have seen a few of these in the collections of Japanese hi-fi hobbyists, but only rarely as the main speakers, seems they are more of a curiosity or experiment.
B-Stock 2155s are still available in the JBL tent sale:
http://www.jblpro.com/commerce/tent_...x.php?cPath=23
Today there are smaller JBL coaxial drivers for installed sound, home theater and automotive applications:
http://www.jblpro.com/pages/install/cc_ceiling.htm
http://www.jbl.com/home/products/cat...=US&Region=USA
http://www.jbl.com/car/products/cate...=US&Region=USA
glen
"Make it sound like dinosaurs eating cars"
- Nick Lowe, while producing Elvis Costello
Thanks Glen. I did a search and found these.
http://cgi.ebay.pl/JBL-LE-14C-WOOFER...QQcmdZViewItem
Not sure the guy knows what they are as they are simply referred to as woofers. But you can clearly see the screen in place of the dustcap,and both high and low frequency terminals.Wouldn't mind trying a pair if these.
Sir, very impressive! May I call you Brother?I am only the second
Nice collection, and nice to see that Dad and I are not the only Urei fanatics out here!
Frederick
I doubt if we'll see any 604 groupies raining on your parade.
Steve Schell gave me an interesting overview of the Iconic and just where the 604 fitted into the overall scheme of things while I was in Long Beach.
Don has also posted an excellent reference thread somewhere of all the trials and tribulations and comings and goings of the drivers used in the Urei "period".
Nice collections and nice cat too......
I am only the second
Class act.
Would love a hi res file for a print..
Ian
Oops, almost forgot the pro versions
http://www.lansingheritage.org/image...pro/page06.jpg
The LE12C was given the model number 2145 in the pro catalogs.
Instead of the LE14C the professional line's larger model 2150 was a full 15 inch D130ish woofer crossing over at 1200Hz to a concentric LE5 cone midrange:
http://www.jblpro.com/pub/obsolete/2150.pdf
This did not have the high compliance foam surround like the LE14C and required a full size 4 to 6 cu. ft. enclosure. Lack of a real tweeter limited high frequency extension but must have been a better match for the bigger, more efficient woofer to create
"...a highly efficient system which can produce a sound pressure
level greater than 100 dB at a drstance of 30 feet. Peak
free response permits greater gain before acoustic feedback."
glen
"Make it sound like dinosaurs eating cars"
- Nick Lowe, while producing Elvis Costello
In Jim Lansing's 1943 article "The Duplex Speaker", he chronicles the progressive downsizing of the Shearer Two Way Horn System to provide high quality sound in smaller spaces. The Shearer was of course an enormous theatre system that used a 375Hz. crossover point.
First step in the downsizing was the Lansing Monitor, with a 500Hz. crossover point which permitted a smaller high frequency horn. It used a folded W bin bass horn that was greatly reduced in size. It worked fine in small preview theatres, but was still a bit large for studio control rooms.
Next came the Iconic with its 800Hz. crossover, smaller high frequency horn and new small format high frequency driver. The desired size being too small to permit use of a bass horn, it used a six cubic foot bass reflex cabinet. It was a successful design featuring wide bandwidth, smooth response and compact size.
The final step in downsizing was the Duplex; the idea had been suggested to Altec in 1941. It combined the basic speaker elements of the Iconic mounted coaxially in a single compact chassis. Crossover point was moved upward once again to 1200Hz., and even higher later on. Most often the Duplex was installed in the Iconic's bass cabinet, now called the 612.
The Duplex in the 612 box became the most popular and long lived monitor speaker in history. It was hard to beat for monitoring in close quarters, and it became the standard for decades.
Some (like me!) might feel that for many uses the Duplex took the downsizing a bit too far. Placing the high frequency horn in the center of the woofer requires a small horn, which in turn requires a high crossover frequency, which in turn requires that the woofer cone be driven up into its breakup region. The Duplex drivers are fine speakers, but do not perform as well as the Iconic in an absolute sense. This was not lost on Altec, who continued to produce a variety of 800Hz. two way systems through nearly all the years of the Duplex drivers' popularity.
When Jim Lansing began JBL in late 1946, he soon began producing a two way speaker system that was reminiscent of the Iconic. It was two way, with high frequency compression driver and bass reflex cabinet of about six cubic feet. The high frequency horn was quite small though, and the crossover was a third order 1200Hz. design. So it seems that his development of the Duplex drivers while at Altec exerted some influence on his later work.
JBL documents the further tradeoffs between point source and power response here:
http://audioheritage.org/vbulletin/s...ead.php?t=4408
Excellent! Thanks Zilch. That is exactly what I was looking for.
Joe
I know the flaws and tradeoffs with Coaxials, and yet? I still love single point source sound for their great and seamless image.
604,s on a medium power, warmish sounding amp, can sound great with a bit of EQ!
scottyj
A generous bit, apparently....
ummm,as uneducated as I am speaker-wise,I wholly agree about the 604c on a medium power warmish sounding amp. And I had to try three and they all sounded different,but with mine,the Pioneer SX60 WAS the one. It was AMAZING after the first two previous tries. I just knew it was THE sound for mine. But they are all different I believe,I really do. But I am NOT like these guys as far as knowing things. I just know what I want to hear and how I want what I hear to make me feel. When it happens,it is almost as close to nirvana as I may get. And I LOVE it. I honestly think I got very lucky with the find of mine,really, and the receiver. And the old DIY walnut cabinets I already had from the previous pair. I know NOTHING about any of these,just that I got lucky and it feels good. For a long time so far...
Last edited by 00Robin; 10-10-2007 at 05:38 PM. Reason: addition
I'm sorry you deleted your post, Scotty, as it would have made for good discussion. I want to be clear that I'm not bashing anything, and certainly not belittling anyone's personal preference or taste.
Surely there is no harm in knowing the facts regarding what we all discuss here every day, and to the best of my knowledge, nobody has previously measured 604 performance and published it in these forums. My findings would seem consistent with opinions expressed by others regarding how they sound. It takes 10 dB of EQ to yank that peak between 2.2 and 6 kHz down.
Now, that's just my measurements of one pair of 604Bs, one of them newly refurbished. I don't know anything about how C, D, E, F, H, K, or L measure or sound, but I'd certainly like to see more objective information, (preferrably by others,
I read the title of this thread, "Why No Coaxials?" and I believe I know why, but I'm certainly not averse to being shown that I am wrong....
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