4430 with reconed E140's and 2425J drivers. Can it be done??

[GordonW]

The E130 and E140 had a 0.875" thick ferrite donut. The 2235H had a 0.75" thick ferrite donut. The flux densities were higher with the E130 and E140 magnetic assemblies. An E130 or E140 reconed with a 2235H kit would yield a hybrid driver with a 1 to 2 dB upward tilt in response across the entire bandwidth; greater sensitivity and a reduction in VLF output.

For use in a 4430 one would most likely need to tweek the 3134 crossover network to compensate. This hybrid transducer could probably be considered as something in between a stock 2234H and a stock 2235H. Note the differences in the 3134 and 3135 networks with respect to the two different transducers.

Yes, this is why I recommended adding about 16 grams (or roughly an ADDITIONAL half of a 2235 mass ring) to a 2235 cone kit, to COMPENSATE for the additional magnetic flux. By doing so, you remove the extra midband gain, and restore the stock Fs/Qts relationship (at least to an extent that gives the SAME bass extension in the SAME box). By doing this, you wind up with a driver that should work just fine with the stock 3134 network...

Point is, it IS a different magnetic assembly... but that's not a show-stopper, not in the least. With an understanding of the basics of what determines efficiency in a driver (which is basically proportional to the term (Sd*Bl)/Mms, where Sd= cone area, Bl= "magnetic strength" and Mms= moving mass of the driver cone assembly), it's a simple enough matter to just add a bit of mass to restore the desired alignment...

Regards,
Gordon.

[Lancer]

I would simply use the proper basket.
Do as you wish.

[Zilch]

[Ummm, he don't HAVE 'em. He's got E140's. Wants to know if they'll work. Answer is "Yes."]



I'm makin' "hotrod" 2235H's outta E140's.

You can BET I'm gonna like 'em, too....

[Ian Mackenzie]

Interesting discussion,

We played around with this during my tech course on speaker design.

While purists may kring at the thought of modifying a JBL, its certainly useful to understand the basic physics of driver motor function.

Custom modifications are the basis of the OEM driver industry, even the likes of Wilson order for example Focal/Peerles drivers modified to specific requirements..its stops diyers negatively engineering their business!

Ian

[Lancer]

[Ummm, he don't HAVE 'em. He's got E140's. Wants to know if they'll work. Answer is "Yes."]

E140 hardware with 2235H software <> 2235H transducer.

A simple equation for those who come to this forum for correct answers.

Naturally you can do as you wish and come up with whatever hybrids you desire. I'm quite confident you will come back and post about said hybrids, detailing how wonderful they sound.

[jkc]

Hi Dutchman



I know the feeling when you can’t find a driver and I had a look at this as I was thinking of some building some 2235’s as well.

You just don’t find 2235’s for sale here and it costs as much as the driver to ship to New Zealand from the US.



An E130/E140 is mechanically compatible.



The following baskets are an Exact Equivalent



2205

2225

2230

2231 (136A/H)

2234

2235

K130, D130 F&H

K140, D140 F&H



There is more to this than meets the eye, it depends on whether the new cone is designed to be underhung or overhung, the magnetic gap depth and the thickness of the back plate.

An E140 for example has the same depth coil as magnet and when the cone shifts forward you get increased distortion but that is OK as it is designed as a guitar speaker and not for Hi Fi use, but I digress.


Hope this helps

[pos]

Sorry to re-open this old thread.

I understand that a E140 reconed with a 2235 kit will not result in a stock 2235H, but something in between a 2234H and 2235H.

Then, going the quick&dirty way, what would a E140 with a foam surround (and maybe a new dustcap?) sound like?
Would it be really different than this already hybrid "2235E" ?
I am considering this driver for a new design, not a JBL clone, so exact 2235H matching is a goal.

[pos]

Let me reformulate my question.
What are the differences between a 2235 and a E140 recone kit?
Is it just in a matter of surround (and colored dustcap) ?
Is it more subtile?

[Earl K]

What are the differences between a 2235 and a E140 recone kit?

- Voice Coil Winding depth is one huge difference between the two .
- The 2235 has quite a deep coil / while the E140 appears to be quite short .
- Both coil types appear to be overhung though since the E140 doesn't have much coil hanging past the edges of the gap / "Xmax" is very retricted resulting in an earlier onset of distortion vs the 2235 design .

FWIW: You should not think of creating a DIY frankenwoofer until you understand a lot more about the basics of transducer design .

- Start by studying all the TS parameters you can get a hold of .

- ie; Qts, Bl factor, mms, Fs, Xmax Vas, Re, Gap Depth ( top-plate thickness ) Voice-Coil Winding Depth ,,, are all important factors in helping one predict the "voice or sonic character" of a transducer .

- Ideally, ( IME ) one needs at least a couple of years for all the info to sink in and become meaningfull. Until that happens , recone some 2225H as 2235H(s) .

[pos]

fair enough
thank you