Page 2 of 2 FirstFirst 12
Results 16 to 22 of 22

Thread: Jbl 2121 or 2122 out of ????

  1. #16
    Senior Member
    Join Date
    Aug 2010
    Location
    Jättendal (Giant Valley), Sweden
    Posts
    738
    I was a bit curious about the different cones, maybe one could reuse the E/K110 cones in a 2121H build, just replacing the surround and the dustcap? So I had a look into the Thiele-Small parameters.

    Code:
    MODEL FS QTS  QMS QES  VAS   EFF  PE XMAX RE  LE  SD    BI   MMS FLUX
    2121  35 0.19 5.5 0.2  110.4 2.7  75 1.52 6.8 0.9 0.032 12.7 25  1
    2121H 35 0.16 5.5 0.17 110.4 2.7  75 1.52 6   0.8 0.032 13.7 26  1.02
    2122H 40 0.23 1.9 0.26  65.1 2.4 100 3.05 5.8 0.6 0.032 13.2 28  1.02
    2123H 85 0.32 2.5 0.37  19.8 3.5 250 2.54 4.2 0.4 0.032 13   25  1.07
    E110  65 0.36 4   0.4   45.3 3    75 2.54 6   0.4 0.032 12.1 21  1.03
    K110  65 0.36 4   0.4   45.3 3    75 1.52 6   0.4 0.032 10.3 17  1.02
    Flux is about the same for all drivers. Since the alnico magnets probably are weaker, the gap is probably a bit narrower.

    MMS is about the same, could the cone itself be the same for all drivers?

    Bl is about the same. They all have about equal number of coil turns in the gap.

    Xmax differs a lot. Different voice coils in different drivers. K110 is close to 2121(H). Is E110 correct?

    Pe and Eff is close between 2121 and K110.

    Vas differs a lot. Must be the surround. 2121 has soft surround. E/K110 has cloth surround. Spiders?

    Qes differs too much. I don't believe Qes can be changed by replacing the surround. Or maybe the spec sheet is wrong? It has happened before :-)

    Qms is pretty close. Softer surround should get higher Qms, right?

    Fs differs a lot. Softer surround should give lower fs.

    Model differs a lot. Can be fixed with foilcal :-)

    I will try to convert a pair of E110, replacing the surround and the dust cap.

    Mårten

  2. #17
    Senior Member
    Join Date
    Aug 2010
    Location
    Jättendal (Giant Valley), Sweden
    Posts
    738
    Quote Originally Posted by more10 View Post

    Quote Originally Posted by 1audiohack
    The voice coil and spider on the E110 looks just like the 2121 pictured, VC is 0.300" tall, the cone is only 0.014" thick. By comparison the 2123's VC is 0.440" tall and the cone is about 0.024" thick. I don't have a 2122 kit to look at.
    I believe converting an E110 to a 2121H by replacing the surround and he dustcap is doable. I really don't like ruining working cones.

  3. #18
    Senior Member
    Join Date
    Aug 2010
    Location
    Jättendal (Giant Valley), Sweden
    Posts
    738
    Speaker Exchange, http://reconingspeakers.com/, also has a few JBL original C8R2121H recone kits in stock

  4. #19
    Junior Member
    Join Date
    Jan 2017
    Location
    hope,nj
    Posts
    6

    looking for JBL C8R2121H

    hi
    need JBL C8R2121H recone kit for jbl 2121 any one have one? looking for factory replacement not aftermarket

    thanks

  5. #20
    Senior Member 1audiohack's Avatar
    Join Date
    Jul 2007
    Location
    Las Vegas Nevada
    Posts
    2,721
    Like these?

    Name:  IMG_0156.jpg
Views: 386
Size:  100.5 KBName:  IMG_0160.jpg
Views: 345
Size:  72.4 KBName:  IMG_0162.jpg
Views: 413
Size:  51.9 KB

    Barry.
    If we knew what the hell we were doing, we wouldn't call it research would we.

  6. #21
    Senior Member DogBox's Avatar
    Join Date
    Aug 2012
    Location
    NSW, Australia
    Posts
    173

    Cool Love 'EM!

    Quote Originally Posted by 1audiohack View Post
    Like these?


    Barry.
    Yum! You bet! They look just like the one's I've got...still.(!) Finally going to get around to doing them and putting them into
    my set-up instead of the... ahem, aftermarket ones (2122) I got instead of the real JBL ones "when you could still get them"...
    I kick myself now for not just biting the bullet and getting proper cones. But from what they told me at Speaker Exchange I tend
    to believe them when they told me 'how good' those particular recones were... They sound quite good...and have been for the last
    9 or 10 years. Checking on the baskets, they're E-110's.
    You haven't been hiding anything in storage have you Barry?

  7. #22
    Senior Member 1audiohack's Avatar
    Join Date
    Jul 2007
    Location
    Las Vegas Nevada
    Posts
    2,721
    Oh I have lots of stuff hidden away.

    Barry.
    If we knew what the hell we were doing, we wouldn't call it research would we.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Field Guide to the JBL 10 inch Midbass driver 2121 2122 2123
    By hjames in forum Lansing Product Technical Help
    Replies: 34
    Last Post: 09-25-2019, 09:38 PM
  2. Needed 2122 help
    By quindecima in forum Lansing Product Technical Help
    Replies: 0
    Last Post: 01-06-2013, 04:46 PM
  3. 2123 with 2122 cone !!
    By lasse in forum Lansing Product Technical Help
    Replies: 9
    Last Post: 12-29-2009, 11:05 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •