idea about the early 2344's

[readswift]

At least , the nice people at the customs office (+!%+!%/=) let me have my original , non-a 2344's I bought a month ago, and Im really really happy about them. Part of this happiness comes from the way they are built, adapter + actual horn area... MODS !! :)


Just found this topic, had no time to read all entirely,
One of the comment entries says:

"Well, properly if to use very fine and very thin (a few mm) sheet of foam and to cover the horn very accurately then it will created the necessary boundary effect of surface randomization"

http://www.goodsoundclub.com/Forums/ShowPost.aspx?postID=6436#6436


Also the 2 piece 2344 assembly would let me do my own way of compression driver mounting , additional foam covering, following the original dimensions closely, but with a "new surface" effectively.
Makes sense?

[readswift]

well anyway, I think I'll wait with this stuff until my buddy has a finished CNC, aquaplas dia's would be enough fun for now :)

[Ian Mackenzie]

I had a read of that thread. Yawn, what lot of noise.

Most of the replies are not supported by any factual data and are way out of context with the real theory behind Geddes work. I would take what is being discussed there with a grain of salt.

You are far better of talking to Geddes over on diyaudio ..he has a nice long thread over there and usually replies to sensible questions but he has attitude and ego so take a wide berth.

There is plenty of experience on this forum around the 2344 and JBL drivers.

As to sandpaper and the 2344 or foam there is absolutely nothing wrong with the way the stock 2344 is engineered. It is what it is as Geddes will / has pointed out. They were used in the longest production run of JBL monitors and nobody complained. Theory and R&D and mnoved on since then and JBL have been making horns that dont sound like horns for quite a while.

The 2344 introduced in the early 80's was purposely engineered and partnered to operate with the JBL specified CD equalisation.

The latter acquaplas treatment JBL poineered is worth a try and this is supported by the original engineer of the JBL 4430-35 models David Smith (JBL).

You need to really be careful of the geometry at the throat of the horn and matching mouth of the (alternative) driver as there will be pinching of the upper octaves and you will never work out why.

Again, the remarks in that thread about the JBL drivers are out of context and really utter f'íng tripe. Myself and others here have used JBL drivers quite sucessfully for years on the 2344. (The stock 2427 was never intended for monitoring applications)

Bolt on a 2420 or 2426 with a stock JBL aluminium / titanium diapgragm and the right JBL passive equalisation and it will work fine from 1000 hertz up. Trying other driver options and you are in a world of frustation and hurt with no engineering support.

Good luck.

[readswift]

thanks for the detailed response! I read the above mentioned topic since, the signal to noise ratio was remarkably low for my taste though I had a good laugh about the Hammerite paint :) The foam idea is supported by the presence of HOM as described by Geddes as far I understand ( I admit, not too much). Im going to ask about preferred mounting & throat coating. The crossovers will be digital, these receive the most of my attention right now, and I even found that nice response graph made by David Smith . The goal is "no capacitor signal path", we'll see how much it worths.

[Ian Mackenzie]

Sounds like you are pioneering in diy territory for sure.

The point I was making is you should start at the original manufacturers base line to amke any sense of this stuff rather than some half baked half arse'd undertanding of a borrowed idea.

The Geddes appoach relies on collective use of a number of pure and applied theories of which the foam phasing plug is just one element..according to a previous email I have from Earl.

Then there is a system integration within which the horn geometry is designed around has noted by Jack.

No capacitor in the signal path and a digital crossover! That's dangerous.

I am sure your diaphragm suspensions will endure the DC drift and digital accidents for a lifetime of musical enjoyment.

Good luck.

[Ian Mackenzie]

Well it sounds like the Cat has spoken....LOL:barf:

I can't stop laughing.......fart!

Fur balls anyone?

That quite a system and looks like retro horn loaded version of Anthony Gallo's spheres.


"I have high respect to Mr. Geddes' knowledge and his "desire to know: but unfortunately his understanding the purposes and the needs of Sound are at kindergarten level. The majority of the folks at this forum are in the same boat and I do not particularly like this community. People in here are experienced with JBL family and they shill the subject of JBL use. I have no interest to people who express a stupid animal loyalty to anything, not to mention that the absolute majority of the people around here are quite clueless about serious sonic result and serious sonic objectives."

I think we've been told!

[readswift]

well, i read about this now, at least a single cap sitting as first order filter has to "isolate" the compression driver. Hm, now this perfectly makes sense.

[readswift]

i would like to exclude romy-teh-berserk
out of the thread here . This one is much more interesting
http://www.diyaudio.com/forums/showthread.php?postid=1301217#post1301217

anyway , I followed that thread there on diyaudio (admit , most of the times over my head) before I came to this forum here , and I wanted to take part in the groupbuy for the Geddes waveguides but that ceased . For now, I think Ill build 2x 4430 instead of the 4435's. The second pair with completely new waveguides..!

[Ian Mackenzie]

I got the impression you worship the Cat over on his forums which is why I posted that image.

Between being the emperor without the cloths and attempting the belittle the respect most people here have for JBL I dont think Earl is having much of an impact. He has some ideas, but they are just that...nothing has been commercialised and I doubt it will while he is around.