reconed k130

[lasse]

Hallo.
What will you pro boys say about a K130 reconed with a 2235 kit ??
Lasse

[Mr. Widget]

The K130 frame and motor are the same as the D130, 136A and others so it would result in an alnico 2235 much like putting the 2235 kit in a 2231.


Widget

[Earl K]

What will you pro boys say about a K130 reconed with a 2235 kit ??
Lasse

- I disagree with Widget ( from the advisablility point of view ) .

- It's waste of a fairly expensive kit , I'd say . Hold out for a healthy 2225 assembly, if you're wanting to recone something into a bona fide 2235.

- Though the kit will fit, & the K130(s)' magnetic assembly has the proper gap depth ( & magnet strength ) / at this stage in it's life, there is now a high likelyhood that the alnico magnet isn't as strong as it once was .

- The result ( of reconing a "weakened" Alnico ) might well be a "Franken-Woofer" that lacks some midrange response from 400 hz upwards .

- Remagnetizing the alnico magnet before reconing would be the way to go / but even that's not a guarantee of success / if the remagger doesn't check the gauss level in the gap .
:)

[Mr. Widget]

- I disagree with Widget ( from the advisablility point of view ) .I neither recommended or discouraged it... simply pointed out the fact that the frame is the same as the 136A. If you own a pair of L300s (with 136As) and you need a recone, the 2235 is your best choice.




- The result ( of reconing any Alnico ) can well be another "Franken-Woofer" that lacks midrange response from 400 hz upwards . Ask Toddalin about his experience here .Are we sure?


Widget

[4313B]

BTW, did anyone see what Greg discovered upon further investigation?

L200b (http://audioheritage.org/vbulletin/showthread.php?t=23408)

[Earl K]

I neither recommended or discouraged it... simply pointed out the fact that the frame is the same as the 136A. If you own a pair of L300s (with 136As) and you need a recone, the 2235 is your best choice.

- I'm sorry I brought your name into it / but it sounded like an endorsement of the concept .


Are we sure?

- No,,, certainly not after looking at the following images . Thanks for the heads'up about these, 4313B .

http://audioheritage.org/vbulletin/attachment.php?attachmentid=36188&stc=1&d=1230656871
http://audioheritage.org/vbulletin/attachment.php?attachmentid=36189&stc=1&d=1230656904
>< cheers :)

[Mr. Widget]

- I'm sorry I brought your name into it / but it sounded like an endorsement of the concept .No worries. I posted my additional post to clarify the facts as I know them. ;)


Widget

[lasse]

Hallo !
Not planning to recone, its already done !!
I been serching for 2235 here in sweden and these came up for sale !!

Lasse

[speakerdave]

To me it is a question of whether the magnets were recharged.

That Alnico-motored family of frames with the 2231 cone kit was a perfectly viable woofer and many thousands of people have enjoyed them in the L300, the 4333 and other JBL speakers of that era. The 2235 cone kit is somewhat different, but not very much, and is for most people close enough to be a drop in replacement for the 2231 in those situations where the 2231 or 136A must be reconed. It is the replacement specified by JBL.

However, many of the events or situations which can lead to the need to recone can also demagnetized the Alnico magnets, specifically, heat, being over driven or dropped or knocked around, etc.

If I were buying those K130's reconed with 2235 kits I would want to know as much of the history as possible, but since it is impossible to know the history thoroughly, I would assume it will be necessary to have the magnets recharged (it can be done with the new cone in place) and would have it done as standard operating procedure; and, I would want the price I pay for the drivers to accommodate the need to have them recharged. Otherwise, I would look elsewhere.

The 2235 cone kit in the Alnico frame will not be exactly the same woofer as the same kit in the ferrite frame, and many would prefer the ferrite. If you plan on driving these woofers hard with a big solid state high current amp, you might be better off waiting for some ferrite framed woofers to come your way. If, on the other hand, you know your power application will be moderate over the long term, fully charged Alnico frames with the 2235 cone kit can give satisfactory performance for many years.

[Zilch]

BTW, did anyone see what Greg discovered upon further investigation?

L200b (http://audioheritage.org/vbulletin/showthread.php?t=23408)Man, how we struggled with that, lookin' in the wrong places, obviously. :banghead:

At least I got the on-axis frequency response correct.... :p

[lasse]

Tjenare grabbar !!
( Thats swedish for, Hallo boys!!)
I`ll skip the k130 recone, and be happy with my four 2231 ( 2 A:s an 2 H:s).
Im planning to build a 4355 clone !!
I have collected four 2231, two 2202H,Two 2441 with the 2390 horn and lens combo, and a pair of 2405H.
Found some plans of a clone 3155 Xo from Mr Widget that i`ll try to build
The cabs volume will be as the 4350, with the dog house for the 2202,would like to build (now i have trubble to explain!!!!)a cab where i could test and compere my 2122H with the 2202.
Of course the XO would be different.
The projekt will start after the summer, my wife desided that we should move out to the contryside.......and i get the extra house for my speakers and music so i`m happy !!:D
She gets a pool!!
When i`ll get started i start thred !!
Sorry for my poor englich !!
Lasse

[Loren42]

!!:D
She gets a pool!!
When i`ll get started i start thred !!
Sorry for my poor englich !!
Lasse

So, what do people in Sweden do with a pool? Skating rink, maybe? :D

[lasse]

I`ts were we keep the pet polarbear !!
Lasse