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hanad400
08-15-2006, 01:02 PM
Hello forum

My first post here, greetings to all, a nice place for discussions and technical help. My question: I have to recone a pair of 2231A with the 2235H kits, should I mount the mass ring, why or why not. The 2231A are from my 4341. Thank you for your help
Regards, Günther

edgewound
08-15-2006, 01:21 PM
Hello forum

My first post here, greetings to all, a nice place for discussions and technical help. My question: I have to recone a pair of 2231A with the 2235H kits, should I mount the mass ring, why or why not. The 2231A are from my 4341. Thank you for your help
Regards, Günther

Welcome to the forum Gunther...Where are you from? I'll guess Europe, no?

For the 2231A (C8R2235)the manual says to mount the mass ring. It will keep the Fs closest to original specs...otherwise you'll end up with an Alnico equivalent 2234 which has Fs of 23Hz.

Fs for 2231A was originally 16Hz; for 2235H Fs is 20Hz.

hanad400
08-15-2006, 01:40 PM
Hello Edgewound

Thank you for telling perfect why to use the mass ring. Yes, I´m from Europe, from Austria. Once again, a nice place for JBL and Altec friends, I´m happy to be in this forum.
Regards, Günther

Anthony L100
08-15-2006, 06:35 PM
Hello forum

My first post here, greetings to all, a nice place for discussions and technical help. My question: I have to recone a pair of 2231A with the 2235H kits, should I mount the mass ring, why or why not. The 2231A are from my 4341. Thank you for your help
Regards, Günther

Hi Gunther, I also have 4341s with the original 2231As and I recently picked up a pair of 2225 baskets (same as 2235s) which I reconed with C8R2235 kits, but I left out the mass ring to yeild 2234s. I tried them in the 4341s with pleasing results IMO, slightly faster, tighter bass. They probably don't go quite as low, although I could not notice. I hope this helps. As you are not experimenting with spare drivers, I would be aware that there is no going back once the dustcaps are fitted! Good luck and please let us know what you decide.

Edgewound, have you ever reconed 2231As as 2234 and if so, was the result good? I'm considering this for my 2231s as the spiders are probably slightly tired by now. Thanks, Tony.

edgewound
08-15-2006, 07:24 PM
Edgewound, have you ever reconed 2231As as 2234 and if so, was the result good? I'm considering this for my 2231s as the spiders are probably slightly tired by now. Thanks, Tony.

Hi Tony,

I've recently reconed 2225 baskets to a 2234H and the result was very good. As you probably know the 2234/35 kit has a slightly stiffer spider resulting in a slightly higher Fs.

This was an upgrade as far as the factory is concerned, and I feel makes for a more robust driver....the enclosures these drivers are tuned to are way above the free air resonance so what's the advantage? A driver that responds quicker mechanically and has the ability to be effectively used in a two way system, with a reasonably high crossover point.

But to keep the 2231 factory spec, I'd stay with the mass ring.

hanad400
08-16-2006, 05:37 AM
Hello Edgewound / Tony

I´ll try reconing first without the ring, don´t fix the dustcap, listen to the result.
Thanks and Regards, Günther

Anthony L100
08-16-2006, 09:04 AM
Hi Tony,

I've recently reconed 2225 baskets to a 2234H and the result was very good. As you probably know the 2234/35 kit has a slightly stiffer spider resulting in a slightly higher Fs.

This was an upgrade as far as the factory is concerned, and I feel makes for a more robust driver....the enclosures these drivers are tuned to are way above the free air resonance so what's the advantage? A driver that responds quicker mechanically and has the ability to be effectively used in a two way system, with a reasonably high crossover point.

But to keep the 2231 factory spec, I'd stay with the mass ring.

Thanks Edgewound, yes I guess i'll leave them in for the sake of original spec as I have the 2225s to experiment with:)

Anthony L100
08-16-2006, 09:11 AM
Hello Edgewound / Tony

I´ll try reconing first without the ring, don´t fix the dustcap, listen to the result.
Thanks and Regards, Günther

Hi Gunther, I think Edgewound will give you the definitive answer but, IMO not having the dustcap glued down will not give you a true impression as there will not be a seal between the front and rear of the cone, which will surely affect the tuning??

edgewound
08-16-2006, 10:02 AM
... not having the dustcap glued down will not give you a true impression as there will not be a seal between the front and rear of the cone, which will surely affect the tuning??

This is true, yes.

hanad400
08-17-2006, 09:49 AM
Hello, I think I go with edgewound and mount the mass ring. Maybe I can get another pair without ring and test which is better for me.

Regards, Günther

grumpy
08-17-2006, 11:21 AM
Hi Günther,

If there's something within my capability that I can test for you, please let me know.
I have both 2234H and 2235H freshly made from 2225's as well as the WT2 test fixture.
I have not yet made a sealed test box to use with WT2, but could be persuaded if there
was interest :)

-grumpy

Zilch
08-17-2006, 11:56 AM
http://audioheritage.org/vbulletin/showthread.php?p=75850&#post75850

Read on to the next page for the isopoteric presentation @ #33.


I have not yet made a sealed test box to use with WT2, but could be persuaded if there was interest :)

Plug the ports of 4507, maybe?

[Plumbers' test plugs.... :thmbsup:]

hanad400
08-17-2006, 11:44 PM
Hello grumpy

Thanks for your help, maybe later.
Regards, Günther

Fred Sanford
03-15-2007, 02:10 PM
Hello all...I figured I'd add these questions here so future searchers might have an easier time of finding related info in one place:

1] I'm working on my 4333As today, and the spiders on the 2231As have sunken quite a bit during their tough life (the woofers are also mis-matched in age/serial #s= 7038 and 24103, so I'm assuming one was replaced during its years of service). With this configuration (internal crossover at 800Hz), am I correct that my best current re-cone option would be the 2235H kit (C8R2235) with the mass ring installed? Is that easily sourced from JBL these days? I see it on the January '07 Transducer Parts List, so I assume it is.

2] What's the opinions on the alnico magnet? Should it be re-gaussed before/during the re-coning process, or is it something I can wait on for another time? These speakers were from Clive Davis' listening room at Arista Records, I know they had a busy life. I'll certainly feel better about transporting them before the re-coning, I'd worry less about damage, but I don't know much about the process, the pricing, or the places that perform it correctly.

Thanks in advance,

je

edgewound
03-15-2007, 02:20 PM
Hi Fred,

The current recone kit for the 2231 is C8R2235. Current price is $180.00ea

It would be prudent to recharge the magnets due to their age of alnico, and especially since they were in a busy studio.

Guido
03-15-2007, 03:08 PM
It would be prudent to recharge the magnets due to their age of alnico, and especially since they were in a busy studio.

Edgewound is right as always.
I recently reconed 2 2231A with 2235 kits (with ring) and measured them.
They where missing 20% of their magnetic energy.
They will be remagged now.

Fred Sanford
03-15-2007, 04:27 PM
Thanks for the replies- any suggestions for repair shops for this service, or is this something many shops can handle without a problem?

je