Announcement

Collapse
No announcement yet.

Refoam - JBL L100T

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Refoam - JBL L100T

    A friend has a pair of these JBL's from the early 80's and asked if I could refoam them. Found a kit on eBay for about $30. Comes with surrounds, glue, shims and instructions .

    Any difference between this and what can be obtained via PE?

    From the looks of things, these 12" woofers are beastly, with cast frames and massive magnet.

    Any comments or suggestions? I told him I would do it for free (he will pay for the materials) as we fished some bass tourneys last year and I didn't have to pay for gas.

    Any tips or suggestions?

  • #2
    Re: Refoam - JBL L100T

    Measure the ID and OD of the JBL surrounds to make sure replacements are comparable.
    "Not a Speaker Designer - Not even on the Internet"
    “Pride is your greatest enemy, humility is your greatest friend.”
    "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

    Comment


    • #3
      Re: Refoam - JBL L100T

      Be warned that some of the JBLs have very tight tolerances in the voice coil gap. Not sure about that particular woofer... Playing a 30Hz test tone can allow you to center the VC without cutting up the dust cap for the shims.

      This sounds like your first attempt at refoaming. Considering the value of those woofers, you should think real hard about finding something cheap to practice on or have them done by a pro.

      Comment


      • #4
        Re: Refoam - JBL L100T

        I had some beginner's luck with refoaming a pair of AR 12 inch and Advent 12inch. Then I ruined an AR 12-inch. It has been a long time since I tried rerfoaming anything. Then I saw this instruction about using cloth pins to center the VC.
        http://www.audiofriends.nl/pdf/refoaming.pdf

        I have since then refoamed over 20 speakers even including the tiny Bose 901 fullranges without any VC rubbing or noises.

        Lesson: There is definetely some tricks in refoaming speakers but it can be done. It is probably safer to remove the dustcap and use shims to center the VC. But if you want to leave the dustcap untouched you can try the cloth pins

        Comment


        • #5
          Re: Refoam - JBL L100T

          It is probably safer to remove the dustcap and use shims to center the VC.
          Centering is more accurate as well:
          Surrounds are glued; shims pulled; and dust-cap replaced.
          "Not a Speaker Designer - Not even on the Internet"
          “Pride is your greatest enemy, humility is your greatest friend.”
          "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

          Comment


          • #6
            Re: Refoam - JBL L100T

            I've refoamed the woofers on a pair of 4313B and L110 of similar vintage, should be similar. I personally do not like to butcher the dustcap and have had good results without using shims. Look here for a good step by step tutorial. This works if your cone is flexible. I would suggest you get the foams only from looneytune2001.

            http://www.audioheritage.org/vbullet...d-Step-by-step

            Comment


            • #7
              Re: Refoam - JBL L100T

              butcher the dustcap
              Use an Exacto ( the hobbyist equivalent to a scalpel ) and offset scissors and it's more like surgery .
              The first surround kits I ever bought did not have shims or a replacement cap.
              The later surround kits I got: included replacement caps for that method of installation ( re: post #5).
              "Not a Speaker Designer - Not even on the Internet"
              “Pride is your greatest enemy, humility is your greatest friend.”
              "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

              Comment

              Working...
              X