112/2108 voice coil

[bldozier]

I read I maybe able to swap a 2122h
vc into 2108s

can anyone confirm or deny that.
Both /.170" at 52 turns

What about a e110h...
http://www.audioheritage.org/vbulletin/showthread.php?35275-112-2108-Voice-Coil
Http://www.audioheritage.org/vbulletin/showthread.php?16962-Field-Guide-to-the-JBL-10-inch-Midbass-driver-2121-2122-2123

[Flodstroem]

If its possible (it looks too) where do you find a 2122 vc? :blink:

[bldozier]

I've seen em Ramon, actually 1. There was a member
whom bought a few pair a ways back from jbl

i just saw a pair of 2122h get sold also a few
weeks ago.

[Flodstroem]

E110:
http://www.audioheritage.org/vbulletin/showthread.php?10635-E110-8

[bldozier]

*wolf whistle*

iam am closer but not there yet.

[bldozier]

2122h's coil
Is the same as an 2108.
Confirmed

[mech986]

Maybe instead of taking a voice coil from a valuable and NLA 2122 cone kit, have someone make one up for you - Edgewound (Upland Loudspeaker), or

Speaker Repair Pros
10382 Stanford Ave. Ste. J
Garden Grove CA 92840
http://www.SpeakerRepairPros.com
[email protected]
1-714-483-8143 Cell
1-714-591-5082 Shop

Both of them have access to aftermarket parts which should be pretty close to the 2122 kit parts, and usually the voice coil assembly is available separately if you ask really nice.

[bldozier]

Did you make a reference to aftermarket
or custom wound kit
its not very clear

[mech986]

Did you make a reference to aftermarket
or custom wound kit
its not very clear

Aftermarket 2122 kits are built up from parts, including a voice coil assembly wound presumably like the original. These are then glued up to the correct spider and cone assembly. If you want a 2122 type voice coil to experiment with on a 2108 type cone, then check with the above shops, or many of the other vendors across the country who may list 2122 aftermarket parts, recone kits, or recone parts. Someone out there is likely making a 2122 type coil which you can get probably easier than a real 2122 OEM JBL kit, and save that for a real 2122 which itself is pretty rare and used in a few rare monitors like the 4350.

[FE3T]

Aftermarket 2122 kits are built up from parts, including a voice coil assembly wound presumably like the original. These are then glued up to the correct spider and cone assembly. If you want a 2122 type voice coil to experiment with on a 2108 type cone, then check with the above shops, or many of the other vendors across the country who may list 2122 aftermarket parts, recone kits, or recone parts. Someone out there is likely making a 2122 type coil which you can get probably easier than a real 2122 OEM JBL kit, and save that for a real 2122 which itself is pretty rare and used in a few rare monitors like the 4350.

What you Write are correct, BUT finding the correct coil are not easy.

I have Access to parts directly from MWA, and no edgewound 3" coil With .170" windings are to be found in their catalog.
Speaker Exchanges aftermarket kit are using a .400" coil and i know they use mostly MWA parts, so i Guess that their Choice of coil
are the the best alternative of what's aviable. (it would make the driver overhung, and result in a Xmax about +/- 1,6mm (3,2mm total)

Other vendors like OCS seem too use the same coil in their 2122H kits.

There are a .170" voice coil aviable from MWA who should fit. BUT its a round wire coil which i doubt would give good results.
(too thin = low Power handling and force)

[mech986]

Thanks for that information. Obviously, not a product that has a lot of demand (the 2108 and 2122 style voice coil). Wonder which voice coil is used in the 2108 aftermarket kits?

Sort of confirms that some aftermarket kits might not be close to the original specifications, but have whatever is available, or whatever might fit, at least in this case. Still, there might be someone with the correct coil, and old coil or kit, or a used piece out there in someone's shop, storage of inventory.

I suppose if someone is looking hard enough, a torn cone 2122 with intact voice coil could be a suitable donor assembly.

[kelossus]

I have a pair of the original C8R112A cone kits with the ribbed cone. I could crack them open to see if there is a part number on them if that would help.

[mech986]

What you Write are correct, BUT finding the correct coil are not easy.

I have Access to parts directly from MWA, and no edgewound 3" coil With .170" windings are to be found in their catalog.
Speaker Exchanges aftermarket kit are using a .400" coil and i know they use mostly MWA parts, so i Guess that their Choice of coil
are the the best alternative of what's aviable. (it would make the driver overhung, and result in a Xmax about +/- 1,6mm (3,2mm total)

Other vendors like OCS seem too use the same coil in their 2122H kits.

There are a .170" voice coil aviable from MWA who should fit. BUT its a round wire coil which i doubt would give good results.
(too thin = low Power handling and force)

If its edgewound copper, and the coil is wound starting at the top, wonder if it could be unwound from the bottom to approximately the correct height and turns numbers?

From this thread: http://www.audioheritage.org/vbulletin/showthread.php?35275-112-2108-Voice-Coil

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=25466&stc=1&d=1180663965

[FE3T]

If its edgewound copper, and the coil is wound starting at the top, wonder if it could be unwound from the bottom to approximately the correct height and turns numbers?

There are a couple of problems with that approach,

1. The .400 coil in the MWA catalog are intended for the JBL G125-8 and are probably wound with aluminum wire.
(G125-8 in oem form have a alu coil) http://www.jblpro.com/pub/obsolete/G125-8_And_G135-8.pdf

2, Unwinding a .400" coil would result in very low DCR (RE in the T/S parameters) , maybe even to low to call the finished product a 4ohm driver.

3. Unwinding a voice coil include a risk of breaking the bond betwin the windings in other places than you intend.

This could be promising for unwinding:
MWA930-16 (3.000 ID) (1.195 FH) (.250 WW)..11.2 DCR
BUT I don't know if its Alu or copper, and I have no idea if its windings have suitable thickness,
it might not even be a 3" coil since its not listed together with the other 3" coils (might be a misprint)
and finally It might not be real edgewound coil but a coil wound in two layers with flat wire laying down instead of on its edge.
Buy at you own risk :dont-know:

[Flodstroem]

How about to use a 2123: 3" coil and make it an overhung midrange? Its 0.420" long, 5.2 ohm minimum and a DCR of approx 4 ohm. But have no idea what X-max then would be :blink:

[FE3T]

How about to use a 2123: 3" coil and make it an overhung midrange? Its 0.420" long, 5.2 ohm minimum and a DCR of approx 4 ohm. But have no idea what X-max then would be :blink:

It seems like Speakerexchange uses the same .400" coil for their 2123H aftermarket kit as they use in their kit for the 2122H, and there are no coil especially for the 2123H in the MWA catalog either.

JBL claims +/- 2,5mm Xmax for the 2123 but the overhang are 1,8mm so I guess JBL`s number are calculated with a certain percentage (10%?) drop in BL

[Flodstroem]

2122 uses the Copper wire coil and 2123 uses the aluminum wire coil. Must be a great difference if compared to weight. Thats why I thought of 2123 coil for the build......... :D

[FE3T]

2122 uses the Copper wire coil and 2123 uses the aluminum wire coil. Must be a great difference if compared to weight. Thats why I thought of 2123 coil for the build......... :D

The .400" coil I have found in the MWA catalog, are a coil for a JBL G125-8 which also uses an aluminum coil.

A coil identical to the one used in 2123 (.420") , I have not found, so if that are to be used, it must be sourced from a Oem 2123 kit or a driver with ruined cone.

But substituting a short copper coil with a aluminum coil if there are no other choice than using a longer coil are a good idea if low moving mass are a goal. (that's probably why Speakerexchange and others uses the .400" coil I their 2122 kits in the first place)

Ps Hvor langt er du villig til å fire på prisen på de LE14H-1 du selger på Finn? Jeg har fryktelig lyst på dem, men med den regningsbunken som skal betales nå i Mars er det å skaffe penga et problem, at jeg har sagt meg villig til å låne sønnen mine et større beløp I forbindelse med et huskjøp gjør ikke problemet mindre. ;)

[Earl K]

Hi FE3T,

How is MWA's catalog laid out from a cross-referencing point of view ( ie; can one do a search using known & required VC dimensions or is one mostly confined to MWA suggestions made according to fixing a specific Manufacturer & Model#) ?

The reason I ask is, Altec mostly used 3" voice-coils and most were short with very fine copper windings ( this, all because Altec used an under-hung gap topology until the bitter end ).

ie; Maybe there's an Altec substitute coil that will come closer ( assuming an Altec 3" coil actually fits into a JBL 3" gap ?? ).

:)

[bldozier]

The basic understanding I've gained thus far
focuses firmly around a .400" kit along with a aftermarket
cone. Usage of that crew makes an overhung
speaker.
Had no one unearthed information on the e110
coil.

not having pdfs to quote isn't helping.
i do feel however if not using a 3" vc
a combination is still possible to mirror
the performance from a 2108/122
in a 2" driver I'd like to think a weighty 2118 cone
may yeild good results. But from the graph the le8
issent far off.

[FE3T]

Hi FE3T,

How is MWA's catalog laid out from a cross-referencing point of view ( ie; can one do a search using known & required VC dimensions or is one mostly confined to MWA suggestions made according to fixing a specific Manufacturer & Model#) ?

The reason I ask is, Altec mostly used 3" voice-coils and most were short with very fine copper windings ( this, all because Altec used an under-hung gap topology until the bitter end ).

ie; Maybe there's an Altec substitute coil that will come closer ( assuming an Altec 3" coil actually fits into a JBL 3" gap ?? ).

:)

The catalog are pretty hard to cross reference.
Only some of the coils have info of what driver it is intended for.
there are no info about wire gauge, outer diameter or anything that makes it easy to decide if a coil can be used in a certain gap.

Attachment shows a small segment of the 3" list

[Earl K]

The catalog are pretty hard to cross reference.
Only some of the coils have info of what driver it is intended for.
there are no info about wire gauge, outer diameter or anything that makes it easy to decide if a coil can be used in a certain gap.

Attachment shows a small segment of the 3" list

Thanks for the overview, FE3T.

:)