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…

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

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 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…

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

And a Beautiful one at that!!

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.

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.