Hello,
I would like to know the biggest fullrange drivers bigger than 12'' which were made by Altec, JBL or others.
What are the drivers names?
Are there some really big fullrange drivers in production today - maybe by some firm in the far east?!
Bye, Dragan
In the classic JBL lines the only "full range" drivers have been the Le8T, the Le12C and the Le14C. The latter two of these were actually coaxial designs. JBL also made Extended Range drivers--the D208, D123, D131 and D130 (plus the Pro Line equivalents and later ferrite versions). These were sometimes used as "fullrange" for hi fi, especially in the early days, but were really designed for PA systems for voice. The D130, 15", is the largest. Other manufacturers (Electro Voice comes to mind) had similar lines. The problem with large full range cones is that they become beamy at a frequency whose wave length approximates the diameter of the driver. Measures taken to extend the high frequencies, like metallic domes or whizzer cones, all have their problems as well.
I'm not aware of any larger full range drivers being made today.
Coaxials have some of the advantages of single drivers. I'm sure you're aware of the various 15" coaxials. The largest one I'm aware of is the 18 " Model 308 by Sunlight Engineering at $9000 per pair. It uses Alnico magnets and is made, according to Dr. Gizmo (Harvey Rosenberg, RIP), by Robert Grunberg. I do not know if it is still in production. I have seen one of these; it is quite impressive indeed. Unfortunately it was not mounted and I did not get a chance to hear it. I believe the crossover was 500 or 600 Hz.
Regards,
David
Take a look in the Altec catalogs for the Biflex drivers. They used a mechanical hinge to decouple the inner cone at higher frequencies so only the smaller area radiated them. At low freqencies the cone was pistonic.
Rob
http://www.lansingheritage.org/image...ome/Page10.jpg
The 15" model 420 as in the Santana was used with a cone tweeter, and with no tweeter did not sound very good, the duplexes are much more highly valued. What are you trying to do?
Harry
Rudy Bozak was a pioneer in the design of large, single element full range drivers. While with Cinaudagraph in the late 1930s, he engineered a line of full range drivers, including a couple of 18" models. These featured 3.5" edgewound aluminum voice coils, and very special cones developed by Bozak. The cones were curvilinear in shape, and graduated from very thin and hard in the center to thick and soft at the outer edge. Good response to beyond 10kHz. was claimed for the 18s. I have the remains of two of these in my shed. One of them still has the spider, voice coil and dust cover intact, and it does indeed have sparkling highs.
Bozak also designed a special 27" driver for the League of Nations display at the 1939 New York Worlds Fair. It had an 8" edgewound aluminum voice coil and a 450 lb. (!) field coil magnet structure.
Looking at coaxials, BTH in England made an 18" model. As was pointed out by speakerdave, Sunlight Engineering markets an 18" coaxial. It is still being made as far as I know.
Steve...
Your depth and breadth of knowledge on this stuff never ceases to amaze me.
Edgewound...JBL Pro Authorized...since 1988
Upland Loudspeaker Service, Upland, CA
agreed....Originally Posted by edgewound
Steve...
Your depth and breadth of knowledge on this stuff never ceases to amaze me.
Mr. Bozak must have been up there when he released the Bozak CMA 10-2DL (considered by some to be the best DJ mixer EVER )
Thanks a lot for the information!
With the beam of large fullrange drivers I have no problem because I have a large distance to my speakers of about 5 meters. Beaming helps to prevent reflections from the room.
For the high frequencies I have a modified EQ with better op-amps and fast capacitors (Behringer 1951).
Now I want to try the Pfleid principle for large band drivers:
http://www.pfleid.de/
I found someone in Germany making a high-end version of the TPS compensation module (phase and amplitude correction for fullrange drivers).
Bye, Dragan
Thanks a lot for the information about JBL and Altec fullrange drivers bigger than 12''.
The biflex principle does not seem to be a good solution. It adds problems to the stability of the membrane. So I will not buy one of these drivers.
The problem with the guitar Speaker from JBL is that the metal dome in the middle of the cone has nasty resonances. It is not a good hifi solution.
I will stick to the E-Voice 15'' fullranger. I'll try to get one!
Bye, Dragan
http://members.tripod.de/Freedom4All/speaker666.html
Yeah, Rudy Bozak was quite a guy. He really deserves a "Bozak Heritage" site. His designs were always innovative and pushing the envelope. He was (I think) the first to use edgewound coils in woofers, and to use edgewound aluminum coils in large full range drivers. He also pioneered exotic pulp formulations and cone geometries in cone making.
The 1930s Cinaudagraph "Magic Magnet" permanent magnet drivers used mammoth (often 50 lbs. or more) magnet structures to achieve high flux density. I can barely lift those 18" drivers in my shed. These models were fitted with studs protruding from the rear of the magnet structure, used with nuts and long cast bars to support the driver's weight. To paraphrase Barry Goldwater, "Extremism in the pursuit of good sound is no vice."
Come to think of it, another noteworthy large full range driver was the Lansing Mfg. Co. model 15H. Based on the field coil motor and cast aluminum basket of the Lansing theatre woofers, it used a 2" aluminum voice coil and curvilinear cone. I have one of these in a 1950s hi fi cabinet out in my shop and it sounds pretty amazing.
As I am alwys fond of watching historic fullrange drivers - do you have foto or can you make some fotos of them?
Is there any comment from AES about the biflex principle? There should be some typical problems with this kind of membrane construction.
Bye, Dragan
People will start expecting all my posts to be on anchient threads. Probably appropo since most are related to anchient drivers!
But a group of fullranges in modern production is the Audio Nirvana models, made up to 15".
Stephen's Trusonic made a 15" Coaxial and a 15" Full range.... A company called PAudio makes some killer 18" Coaxials...
JBL L15
Parting Out>>JBL Athena S99
...Altec Model 604s. Technically, this full frequency driver is two drivers (a HF compression driver and cone woofer) mounted on the same frame but it is generally referred to as a single driver (e.g., The Altec 604), I suppose.
Anyway, this "single" driver was the industry standard in movie houses and recording studios for +25 years.
Sure, no one here has even mentioned the planar-type and electrostatic speakers that can have relatively huge full-range "drivers."
Just thinking "outside of the box."
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