JBL 2122H recone question

[bjh]

Does anybody have experience with the aftermarket recone kits for 2122H from speaker exchange? https://reconingspeakers.com/product...et-recone-kit/

They claim to be "as close to original as possible" I noticed they say the voice coils are wound with aluminum, not copper. I thought the originals were copper. I have a line on some originals but they are many times more expensive ($350 each) I just don't know if they are worth 5x. This would be for a set of 4345 clones I'm building.

[speakerdave]

I believe a phrase may have been left out of that claim, and I think I can fill it in: ". . . As close as possible for somebody who doesn't care what he does or says."

As for the asking price on the authentic kits--only you can decide. There is an option, though; you could follow 4313b's adapted build using the 2123. That build also substitutes a JBL large format compression driver with a dusted diaphragm.

[edgewound]

Does anybody have experience with the aftermarket recone kits for 2122H from speaker exchange? https://reconingspeakers.com/product...et-recone-kit/

They claim to be "as close to original as possible" I noticed they say the voice coils are wound with aluminum, not copper. I thought the originals were copper. I have a line on some originals but they are many times more expensive ($350 each) I just don't know if they are worth 5x. This would be for a set of 4345 clones I'm building.

The voice coil for this kit linked is for a G125A with a winding length of .400", way too long. The winding length for the 2122H is .170". Since edgewound voice coils for the particular driver are currently not available, it makes sense to use a copper round wire coil of the same dimension to at least replicate the frequency response while giving up very small amount of sensitivity. I know it sounds like blasphemy to use a round wound coil in the driver, but having the same winding length in an underhung topology makes more sense than having a way over hung coil that is more than double the winding length.

Hope that helps.

[rogerjulien]

Hello,

last year I ordered recone kits for 2122 at speaker excange.
After some emails they fitted the kit with a .290 edgewound VC for me.
Thats not the .170 origin but the closest they could get.
Have not done the reconing yet but I will post data when the job is done.

Is there any source to get a .170, even when it is a round copper wire?
I'd also prefer a underhung VC.

best regards Roger

[FE3T]

MWA KVC8509-8
3.000" ID
.9" former length
.170" winding
Copper, round wire.
Kapton former.

Thats the only 3" coil with 0.170 winding i could find in the MWA cataloque.

MWA does not sell to individuals, BUT Speaker exchange are a dealer, and should be able to get them.

Beware. these things are flimsy, not even close too the oem edgewound coils robustness.
I beleive they are very easy to deform out of roundness.

[rogerjulien]

Thanks FE3T for the information and the warning.
I'd rather go with the .290 edgewound even if it is to long.

Had a long talk to a friend, JBL fan, and he recomended hardly not to
take the round wire VC due to less material in the magnetic gap wich may
end up with less efficency.
The additinal weight of my 0.290 may do the same but hopefully not that much.
I am aware of the other statement in this thread that differs.
When the speaker is build, it will be messered and I'll post the specs.
I have the kit so thats what I can do. The basket to take is a E110.

In this thread http://www.audioheritage.org/vbullet...-2123&p=171651 there is a good listing of 10" and ther is written that the magnets and baskets are mostly the same.
Does the poleplate have the same thickness 2122 compared to E110?

Sry bjh if it feels like robbing your thread.

[FE3T]

I'd rather go with the .290 edgewound even if it is to long.

With a .290 voicecoil, and a .280 gap.
You will still get an overhung driver, end up having close to zero linear excursion.
and probably have a driver that distorts early.

The oem .170 in the 2122H gives it a tad less than 2mm each way.

The .400 coil Speakerx uses gives around 2,5mm linear xmax each way.
This makes it a better choice than the .290 in my opinion, Aluminum wire keeps the mms closer to the original.
Linear Excursion are closer to the original. and BL doesent differ much either. (based on specs from 2123H and G125-8)

[rogerjulien]

Hi,

the recone kit is assembled and has been messured.

Distortion is no problem imo when used like intended above 290Hz,
95dB k2 - 0,5% and k3 - 0,25 at 200Hz; 105dB k2 1% - 250Hz and k3 0,6% at 200Hz.

The TSP are close enough to the original but vari a little in some points.

FS: 48,9 Hz
QTS: 0,27
QMS: 4,58
QES: 0,289
VAS: 58,7 l
RE: 5,6 Ohm
LE: 0,58 mH
BxL: 11,9

I assume the spider given by speaker exchange is an C,
a bit to stiff and a B would be better.


Mailed them, waiting for an answer and maybe reconing another pair.

[Ian Mackenzie]

Interesting.

The 2123H with an updated mid crossover filter is a very good alternative.

[rogerjulien]

Speaker exchange replied allready, its a B spider in there recone kits for the 2122.
That should be the right one.

The 2123 is a complet different driver and even with a costumized xover
it will allways be a substitute.