2121H out of E110

[Chevelle]

Hello everybody,

I am planing to build a 4343 clone. By this time I have all components from a 4333 clone: 2235, 2420, 2405. As the 2121 is hard to find I read in this Forum about converting a E110 to a 2121H. Member more10 suggested to only change the surround and dustcap to build a 2121H. So my questions are:

Is the vc of a E110 the same as 2121H ? I saw a picture of the 2121 vc but did not see the one from a E110.

Is the cone of the E110 of the same weight as from a 2121H ?

The diameter of the cone seems to be the same so cutting the cloth surround at the edge of the cone and replacing with a foam surround seems to be no problem. Also it is easy to cut out the dustcap and fixing a inverted dustcap from the 2121H.

Thank you for help !

Hjalmar

[ivica]

Hello everybody,

I am planing to build a 4343 clone. By this time I have all components from a 4333 clone: 2235, 2420, 2405. As the 2121 is hard to find I read in this Forum about converting a E110 to a 2121H. Member more10 suggested to only change the surround and dustcap to build a 2121H. So my questions are:

Is the vc of a E110 the same as 2121H ? I saw a picture of the 2121 vc but did not see the one from a E110.

Is the cone of the E110 of the same weight as from a 2121H ?

The diameter of the cone seems to be the same so cutting the cloth surround at the edge of the cone and replacing with a foam surround seems to be no problem. Also it is easy to cut out the dustcap and fixing a inverted dustcap from the 2121H.

Thank you for help !

Hjalmar

Hi Chevelle,
I would suggest You not to do anything with e110 , for the beginning, and to try to see how it sound in your system. I would suggest You to use some of 244x driver with 2311 horn instead of using 2420 and 2307. Such combination has far more natural mid range sound.
Regards
Ivica

[Earl K]

I believe you can make a pretty useful midranger from those E110's /though it'll never be an exact copy of any JBL pro mid ( past or present ).

Here's a good thread (http://www.audioheritage.org/vbulletin/showthread.php?16962-Field-Guide-to-the-JBL-10-inch-Midbass-driver-2121-2122-2123) ! to get you started.

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

I wouldn't fixate on getting the foam surround swapped in, as much as getting the mms value close to correct .

In fact, I would first start by swapping out the metal dustcap for either a 3" paper ( normal orientation ) or 4" paper ( inverted ).
After that, I would measure the mms and then ( if necessary ) add mass to the cone ( by means of an aquaplas substitute ) .

JBL Theile Small Parameters (http://www.jblproservice.com/pdf/thiele%20small%20parameters/theile%20parameters.pdf)

:)

[Chevelle]

Hi Chevelle,
I would suggest You not to do anything with e110 , for the beginning, and to try to see how it sound in your system. I would suggest You to use some of 244x driver with 2311 horn instead of using 2420 and 2307. Such combination has far more natural mid range sound.
Regards
Ivica

Hi ivica,

vintage JBL components are hard to get in Germany and shipping costs from US are expensive. It was a nightmare to get 2312 horns for my 4333 clone. So I will stay with the 2420 / 2307 combo. Anyway I use the Radian dias and I am very happy with them.
I bought a pair of working E110 from spain, they should arrive after eastern. Will test them first in the system as you suggest. Anyway I would like to know what the two drivers have in common.

Hjalmar

[Chevelle]

I believe you can make something pretty useful with the components that you have in hand ( & your approach ) /though it'll never be an exact copy of any JBL pro mid.

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



:)

Hi Earl K,

is there any spec sheet of a 2121 like the one from the E110 ? For example the number of windings on the vc are very interesting.

Hjalmar

[Earl K]

Hi Earl K,

is there any spec sheet of a 2121 like the one from the E110 ? For example the number of windings on the vc are very interesting.

Hjalmar

Not that I've seen.

Here's the 2122H spec sheet! (http://www.audioheritage.org/vbulletin/showthread.php?10637-2122H)

These spec sheets are all located in the Transducer Information Library (http://www.audioheritage.org/vbulletin/forumdisplay.php?59-Transducer-Information)

:)

[1audiohack]

I just built four 2121's and still have two kits to install.

I can count the VC turns while they are out. Anything else?

Barry.

[1audiohack]

I count 59 turns at 0.288" tall.

Barry.

[Chevelle]

I count 59 turns at 0.288" tall.

Barry.

Thank you ! As soon I will receive the E110 I will listen to them in the system.

Hjalmar