+ Reply to Thread
Page 1 of 2 12 LastLast
Results 1 to 10 of 15

Thread: refoam problem

  1. #1
    Join Date: Aug 2012

    Location: Lincs

    Posts: 710
    I'm Philip.

    Default refoam problem

    Well i just refoamed the woofers on soem jbl l26.

    I used the 30hx method.

    One seems good, not sure about the other.

    On the good one...werever i press on the cone it is silent...no rubbing at all.

    On the other, if i press in the very centre or on one side it is ok, no running.
    But if i press on the other side or just off centre on that side then there is rubbing (1cm off centre).

    Should there be no running wherever i press on the ocne?

    OK?
    Refoam?
    Can i loosen one side and reglue?

    Thanks for any advice

  2. #2
    Join Date: Aug 2012

    Location: Lincs

    Posts: 710
    I'm Philip.

    Default

    Does it count as rubbing if one has to push slightly off centre to get it to rub?
    It seemed fien when glueing, but after 2 hours i am not so sure now.

    As i said, the other has no rubbinng whatsoever.

  3. #3
    Join Date: Apr 2012

    Location: Southall, West London

    Posts: 41,100
    I'm Geoff.

    Default

    I'm sure I advised you on this before.

    Why would you use the (dubious) 30Hz method if the rear spider had not been detached? The coils would probably have been correctly aligned anyway, assuming nothing disastrous had happened to the speakers. I bet some bright spark suggested taking the dust caps out too.

    You may be able to run a sharp object like a small screwdriver blade along the underside of the glued surround and release it, so it can be realigned. I always use a water based glue, so the cones can be moved around for a while and initially only bond them in three places in any case until I'm happy the alignment is OK.
    "when common sense, logic and plausibility are excluded. All that remain are foolishness and lies"

  4. #4
    Join Date: May 2008

    Location: Surrey

    Posts: 6,268
    I'm Rob.

    Default

    You must make sure that your thumb and the three fingers starting with the index are central around the dust cover/pole piece. If not you will not get a true idea. Try playing some music through them and see if you get any distortion.
    Buy Bose...And get your parking validated!.

    https://youtu.be/ZCBe7-6rw4M

  5. #5
    Join Date: Aug 2012

    Location: Lincs

    Posts: 710
    I'm Philip.

    Default

    I use the kit as reccomended by the lansing heriatge website, supplied by R Cobb.
    Water based glue, 30hz cd.

    Should there be no rubbing at any point wherever i press?

  6. #6
    Join Date: Apr 2011

    Location: cheltenham

    Posts: 554
    I'm matt.

    Default

    I.had a brand new driver that only rubbed when pressed on one side. Once fitted in the enclosure and with a 20hz signal played through it (to run it in). It produced an obvious distorted sound that the good driver didn't, so I sent it back.

  7. #7
    Join Date: Aug 2012

    Location: Lincs

    Posts: 710
    I'm Philip.

    Default

    All i not lost.

    I manged to use a small brush and water to release the glue along a third of the surround.

    Repositioning it closer to the outside eradicated all rubbing.

    So a little clean up, a little glue and hopefully all will be well.

    failing that, i was sensible in that i ordered two surround kits.
    If this doesn't work i`ll arm it out!

  8. #8
    Join Date: Aug 2012

    Location: Lincs

    Posts: 710
    I'm Philip.

    Default

    I tried using pegs to get best fit.
    Wasn't really getting anywhere so took them all off.
    All of a sudden no scraping anywhere.
    Time will tell whether it will be like that when dry.

    This is easy when it goes right.
    Not so much if there is a tricky one.

  9. #9
    Join Date: Apr 2012

    Location: Southall, West London

    Posts: 41,100
    I'm Geoff.

    Default

    I've said before, the surround is bonded to the cone first. There's usually a visible 'ring' on the cone where the old one was, so just use that as your guide. Then fix the surround temporarily to the chassis lip using BlueTak in three equally spaced positions. That allows you to move the surround about until the cone moves freely back and forth, then leaving the BlueTak in place glue the cone also in three small places between the BlueTak blobs, allow to dry, remove BlueTak and glue the rest of the surround. Your cone should be perfectly positioned.
    "when common sense, logic and plausibility are excluded. All that remain are foolishness and lies"

  10. #10
    Join Date: Aug 2012

    Location: Lincs

    Posts: 710
    I'm Philip.

    Default

    Quote Originally Posted by walpurgis View Post
    I've said before, the surround is bonded to the cone first. There's usually a visible 'ring' on the cone where the old one was, so just use that as your guide. Then fix the surround temporarily to the chassis lip using BlueTak in three equally spaced positions. That allows you to move the surround about until the cone moves freely back and forth, then leaving the BlueTak in place glue the cone also in three small places between the BlueTak blobs, allow to dry, remove BlueTak and glue the rest of the surround. Your cone should be perfectly positioned.
    Thanks.

    As i said, after trying the 30hz method, and then clothes pegs (similar to bluetack i guess), it seems that i fell on the correct allignment by luck.
    It seems to be drying that way as well.

    I thought the 2nd one would present a problem, as after removing old foams it was easy to push the cone down on the first with no noise, but very hard on the 2nd.
    I think the 2nd has a much finer gap tolerance for some reason.

    I'll be able to listen to them at around 11pm tonight when glue as fully cured.

+ Reply to Thread
Page 1 of 2 12 LastLast



 

Posting Permissions

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