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  »  New  Problems with horns: mid-range horns...  First or second order for 1" driver....  Horn-Loaded Speakers Forum     8  44903  07-21-2004
  »  New  Evaluation of tractrix curves based on visual surface r..  Re: The Delay of Time Delay...  Horn-Loaded Speakers Forum     17  72022  06-20-2006
  »  New  Earl Geddes: Horny Book..  Horns, Earl, bottomeaters Sound and confidence of ignor...  Horn-Loaded Speakers Forum     10  51688  07-19-2006
  »  New  Does horn surface porosity influence sound ?..  other possible materials that might be used....  Horn-Loaded Speakers Forum     11  35765  02-11-2007
  »  New  Adding one more non-spherical to Macondo...  Horn suggestions for 300Hz-1000Hz channel...  Horn-Loaded Speakers Forum     23  78569  12-15-2010
02-01-2008 Post does not mapped to Knowledge Tree
Wojtek
Pinckney (MI), United States
Posts 150
Joined on 09-01-2005

Post #: 21
Post ID: 6521
Reply to: 6519
Soft phenolic drivers
This is probably the reason I can listen to EV Patrician IV in relatively small space and close to the speaker without much of fatigue.  The other factor must be that it's 4- way design with narrow band-pass for each horn. EV T25 2" phenolic compression driver (alnico) is still cheap on Ebay although JamminJersey list it for $400 a pair, seems like it's gaining popularity. I have infamous JBL2470 1" big magnet alnico with phenolic diaphragm and was thinking about fundamental channel design around phenolic driver >500Hz -1000Hz counting on dia ability to play lower into LF without breakdown. The thing is I don't know if there would be any advantage over cone midbass streching up to 1000Hz without buying big expensive 250-300Hz horn .
Regards, W
02-01-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 8,793
Joined on 05-27-2004

Post #: 22
Post ID: 6522
Reply to: 6521
The phenolic and none phenolic cones…

 Wojtek wrote:
This is probably the reason I can listen to EV Patrician IV in relatively small space and close to the speaker without much of fatigue.  The other factor must be that it's 4- way design with narrow band-pass for each horn. EV T25 2" phenolic compression driver (alnico) is still cheap on Ebay although JamminJersey list it for $400 a pair, seems like it's gaining popularity. I have infamous JBL2470 1" big magnet alnico with phenolic diaphragm and was thinking about fundamental channel design around phenolic driver >500Hz -1000Hz counting on dia ability to play lower into LF without breakdown. The thing is I don't know if there would be any advantage over cone midbass streching up to 1000Hz without buying big expensive 250-300Hz horn .

You are very much might be correct. Electro-voice and Klipsh used phenolic driver quite aggressively and some of their their speakers had some send of softness and non aggressiveness. I certainly not willing to admit that all phenolic are soft but it would be just a general tendency that metal cones are more … “momentary”.  Another example is Cogent that use phenolic – thy too soft and do not go transiently where I would like them to go. In case of Cogent the softened is also come for the electromagnet that makes then overly polite…

I think a cool direction to go might be to use a naked fibers or soaked cloth, I never tried but I would it I were in driver making business, The best metal cones do fine as they damped with soft suspension, with loading and in some cases with proper coating (like JBL uses aquaplass). I also do not feel that the driver’s resonances is necessarily are bad things, the main question to me is what kind of resonances they are. In the end if one know the driver well and the driver has right characteristics then it is always possible to deal with the specific driver imperfections.

Using horn drivers is in a way like dressing an ugly woman. The woman know what she need to do with herself in order to hide what is not necessary to expose and what to highlight as the most tradable commodity. The drivers are the same… They are all upon our will…

Rgs, Romy the caT


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
02-02-2008 Post does not mapped to Knowledge Tree
el`Ol
Posts 225
Joined on 10-13-2007

Post #: 23
Post ID: 6528
Reply to: 6519
Altec phenolic drivers

Just another paging stuff, or something serious?
http://cgi.ebay.com/ALTEC-VINTAGE-290E-GIANT-VOICE-COMPRESSION-DRIVERS_W0QQitemZ170189928173QQihZ007QQcategoryZ73372QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

02-02-2008 Post does not mapped to Knowledge Tree
op.9
Harrow, United Kingdom
Posts 61
Joined on 01-26-2007

Post #: 24
Post ID: 6529
Reply to: 6528
Compression Ratios

Fascinating stuff. I'm certainly going to try to get my hands on some 2440's when I can see them for a nice price.

That 18 Sound ND2060A looks very interesting to me. And would fit in with my silly philosophy of only using currently manufactured components...  

But it got me thinking about compression ratios in general – since 3":2" = 2.25:1 seems very different from 4":2" - 4:1. This must make for a very different type of sound.

Any ‘rules of thumb’ here?

op.9
02-02-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 8,793
Joined on 05-27-2004

Post #: 25
Post ID: 6534
Reply to: 6529
The compression ratio and Mother Teresa

 op.9 wrote:
That 18 Sound ND2060A looks very interesting to me. And would fit in with my silly philosophy of only using currently manufactured components... 

That ND2060A does look very interesting. I never heard or even saw it but who knows – it might be good. The type of the diaphragm that they use is very promising… if you lay you hard on this driver then let know… BTW, the “silly philosophy of only using currently manufactured components” is as silly as a desire of a musician to play only currently manufactured instilments, or the music of the currently alive composers. I think the next step would be a desire to use components only manufactured in April, only components in triangle shape and the only components that were touched by a person who saw Mother Teresa between 3 and 4 times… :-)   Manufactures might desire to use the currently manufactured components – it understandable but for us – the people who need juts one set of drivers over entire life - I think this peruse of current components is not reasonable....

 op.9 wrote:
But it got me thinking about compression ratios in general – since 3":2" = 2.25:1 seems very different from 4":2" - 4:1. This must make for a very different type of sound. Any ‘rules of thumb’ here?

None that I personally have seen. Generally I always consider that higher compression ratio eats sound’s fine points (there are reasons why) but I also have seen OK sounding higher compression ratio drivers. I think that it is not about the absence of any “rules of thumb” but about our disability to evaluate the relationship between compression and sound. The problem that each compression level require own proper implementation of loading. We can change compression but we do not know if for the given compression the loading is done identically properly as it was for the former compression. We do not make drivers (at least I do not do) we just get whatever is there and use them. I do not think that this approach permits methodologically correct evaluate the contribution of compression. With all said above I would vote not for more or less compression but for the appropriate loading of a given compression…

The caT


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
02-03-2008 Post does not mapped to Knowledge Tree
el`Ol
Posts 225
Joined on 10-13-2007

Post #: 26
Post ID: 6540
Reply to: 6522
Nylon/Latex
 Romy the Cat wrote:

I think a cool direction to go might be to use a naked fibers or soaked cloth, I never tried but I would if I were in driver making business,
Rgs, Romy the caT



Some years ago, when I discovered a Coles tweeter with a relatively flat-shaped Nylon/Latex diaphragm, my first thought was whether it is possible to horn-load something like that, although I wasn´t very interested in horns at that time.
03-11-2008 Post does not mapped to Knowledge Tree
op.9
Harrow, United Kingdom
Posts 61
Joined on 01-26-2007

Post #: 27
Post ID: 6894
Reply to: 6529
What do I have here?
Romy,
I took your advice and now have a single 2440 driver. At least i THINK its a 2440. On opening it i find that it has a phenolic diaphragm! Have I been sold something else? I was not aware that there were ever any phenolics for the 2440 family. Was going to order some new Radian aluminium diaphragms anyway, but i'd be very interested to know what I have here.

http://picasaweb.google.com/jbjbjbjbjb/Jbl

Anyhow, it tests ok and first impressions loaded in the horn are good. It seems very pretty on massed strings and is very lively sounding. Maybe this is the answer, if I can find it a wife...

all best
op.9
03-11-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 8,793
Joined on 05-27-2004

Post #: 28
Post ID: 6895
Reply to: 6894
The poltergeist JBL?
Op,
 
I clearly have no idea as I never have seen/heard about the 2440 with phenolic diaphragm. Who know perhaps they did it. The phenolic diaphragms were the invention in late 60-70s and a remedy against the nastiness of the first SS amplification. They are OK but to my taste they have no necessary for me transient characteristics. Interesting is that the new Radian production of the aluminum diaphragms is much more interesting then the original JBL production – so you are in a good path. I would be VERY interesting to hear your feedback about your new MF driver.

Rgs, Romy


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
03-11-2008 Post does not mapped to Knowledge Tree
op.9
Harrow, United Kingdom
Posts 61
Joined on 01-26-2007

Post #: 29
Post ID: 6896
Reply to: 6895
1st discovery
Looks like it will be a long learning curve...

first discovery - I've matched the levels of the jbl vs BMS accurately - and subjectively the jbl sounds 3-5db louder. and much fuller. very healthy sound too.

I'm going to take this chance to listen to lots of nice old mono recordings. I often neglect them...Should be fun

op.
03-11-2008 Post does not mapped to Knowledge Tree
op.9
Harrow, United Kingdom
Posts 61
Joined on 01-26-2007

Post #: 30
Post ID: 6897
Reply to: 6896
Update
A kind chap from the Lansing Heritige forum has identified my new driver as a 2482. Interestingly those good radian people do an replacement aluminium diaphragm for this driver.

What remains to be seen is how big the advantage of the original phenolic is at the lower cutoff. It looks very very smooth on my RTA with hp at 700hz 6db/octave. I haven't run it full range at the top yet.

op.9
03-11-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 8,793
Joined on 05-27-2004

Post #: 31
Post ID: 6898
Reply to: 6897
Well, from a certain perspective she is a Jaguar :-)




"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
03-11-2008 Post does not mapped to Knowledge Tree
yoshi
Jefferson (MA), United States
Posts 68
Joined on 05-04-2005

Post #: 32
Post ID: 6899
Reply to: 6897
JBL 2482
The picture sure does looks like 2482 and it comes with Phenolic disphram (I have a pair though never used), but it's more like a mid-low driver.  JBL's recommendation is 300~6k.

http://www.jblpro.com/pub/obsolete/2482.pdf

Yoshi
03-12-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 8,793
Joined on 05-27-2004

Post #: 33
Post ID: 6900
Reply to: 6899
...and JBL 2440
http://www.jblpro.com/pub/obsolete/2440.pdf


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
03-14-2008 Post does not mapped to Knowledge Tree
serenechaos
lost alamos
Posts 86
Joined on 12-01-2007

Post #: 34
Post ID: 6909
Reply to: 6898
Well, from a certain perspective she is a Jaguar :-)

And a Beautiful one at that!!

04-17-2008 Post does not mapped to Knowledge Tree
op.9
Harrow, United Kingdom
Posts 61
Joined on 01-26-2007

Post #: 35
Post ID: 7238
Reply to: 6909
More drivers..
Me again..

In my search for another jbl 2482 I chanced upon a Yamaha JA6601 Driver.

http://picasaweb.google.com/jbjbjbjbjb/YamahaJA6601

It looks very similar to the one that produces these amazing response plots on the Azura 204 horn.

http://www.azurahorn.com/Yamaha_on_204.pdf

I haven't yet had a chance to have a listen to this driver. Has anyone else had experiance of it?
I wonder what the difference is between the JA6601 and JA6681. Is it perhaps just 8R vs 16R?

Oh, and I'm going to need another one.....

cheers
james
04-17-2008 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 8,793
Joined on 05-27-2004

Post #: 36
Post ID: 7243
Reply to: 7238
MF driver: what do not look for.

James, I am not familiar with those drivers. You might inquire at the sites that specialize in audio archeology, like AudioHeritage.com and others. They most likely know who made for Yamaha that driver.  However, there are a few thighs that I would like to mention in context of the Azurahorn result you posted above.

The measurements above were made with a microphone positioned at mouth – from my point of view it is not admissible and it says about nothing. BTW, the +5dB blip at 10.5kHz is too brutal but most likely will not be there at 8-12 feet and the slightly off axis shooting. Also, and it is probably the most important – do not look for MF driver based upon it’s response. Look for the right sound “full range” (I use the TTH characteristic) and upon you found what you need then learn bout the driver response and deal with the response idiosyncrasies.

Rgs, Romy the caT


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
09-01-2009 Post does not mapped to Knowledge Tree
orca254
Posts 1
Joined on 09-01-2009

Post #: 37
Post ID: 11628
Reply to: 6894
Still Looking for that JBL 2482 ??
If you are still looking, there are a pair of vintage JBL 2482 Drivers with JBL 2328 horn throat adapters attached currently on Ebay.  The guy says he also has another one he could sell as a single if you are still interested. 

http://cgi.ebay.com/VINTAGE-PAIR-JBL-2482-16-OHm-Drivers_W0QQitemZ150369836858QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item2302bd9f3a&_trksid=p3286.c0.m14
09-01-2009 Post does not mapped to Knowledge Tree
op.9
Harrow, United Kingdom
Posts 61
Joined on 01-26-2007

Post #: 38
Post ID: 11629
Reply to: 11628
Sad singles..
Thanks Orca, I found another 2482 a while ago...
however I do have some sad singles here
I'm looking for another JA6601 (this is a midrange only 6681 as far as I can tell) and also another Pioneer PD-801 and also a Renkius-Heinz SSD 3301 (this one sounds really quite interesting...)
anyone?
op.9
04-11-2011 Post does not mapped to Knowledge Tree
gordan
Posts 12
Joined on 01-29-2009

Post #: 39
Post ID: 16002
Reply to: 7238
Why not 2482
Roman,I don't think I've ever read your explanation why not 2482? We are all on a holy grail path to find a (somehow) available good compression driver that can go down to almost 200hz in domestic conditions and there are not many better candidates. Have you ever finished your examination and testing of 2482 or you were just discouraged by it phenolic diaphragm you don't like. If it's a diaphragm only, Radian aftermarket aluminium ones could improve a transient response, if you here any issues there with an original one.
04-11-2011 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 8,793
Joined on 05-27-2004

Post #: 40
Post ID: 16004
Reply to: 16002
No “search” anymore from me.
 gordan wrote:
Roman,I don't think I've ever read your explanation why not 2482? We are all on a holy grail path to find a (somehow) available good compression driver that can go down to almost 200hz in domestic conditions and there are not many better candidates. Have you ever finished your examination and testing of 2482 or you were just discouraged by it phenolic diaphragm you don't like. If it's a diaphragm only, Radian aftermarket aluminium ones could improve a transient response, if you here any issues there with an original one.

Gordan, I did not have this driver. I never pursued it exactly because you have mentioned – the phenolic diaphragm. I do not know if the design of this driver will allow using other diaphragms. Also, I do not exactly in the Holy Grail path to find a driver that can go down to 200Hz. Sometime I do express those ideas and then I cool down to it. To have a dedicated Midbass horn convert the frustration from an absence of a 200Hz compression driver into juts some curiosity… BTW, the RCA older driver did reportedly go to down to 200Hz… 

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
Page 2 of 3 (41 items) Select Pages:  « 1 2 3 »
   Target    Threads for related reading   Most recent post in related threads   Forum  Replies   Views   Started 
  »  New  Problems with horns: mid-range horns...  First or second order for 1" driver....  Horn-Loaded Speakers Forum     8  44903  07-21-2004
  »  New  Evaluation of tractrix curves based on visual surface r..  Re: The Delay of Time Delay...  Horn-Loaded Speakers Forum     17  72022  06-20-2006
  »  New  Earl Geddes: Horny Book..  Horns, Earl, bottomeaters Sound and confidence of ignor...  Horn-Loaded Speakers Forum     10  51688  07-19-2006
  »  New  Does horn surface porosity influence sound ?..  other possible materials that might be used....  Horn-Loaded Speakers Forum     11  35765  02-11-2007
  »  New  Adding one more non-spherical to Macondo...  Horn suggestions for 300Hz-1000Hz channel...  Horn-Loaded Speakers Forum     23  78569  12-15-2010
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