Page 1 of 3 123 LastLast
Results 1 to 15 of 35

Thread: Cone sag

  1. #1
    jim henderson
    Guest

    Cone sag

    I just bought a 2226 off of eBay and noticed that the cone/spider has sagged as if the driver has been stored face up for a long time. The offset looks like quite a bit but measures only 0.170”. Is this going to be a problem? If I mounted the driver facing down would it eventually correct itself?

  2. #2
    Senior Señor boputnam's Avatar
    Join Date
    Apr 2003
    Location
    northern california
    Posts
    6,142
    Can you post pics that show what you see?

    Any evidence of these having been previously worked on?

    I don't believe you can "restore" a sagged spider. Recone...
    bo

    "Indeed, not!!"

  3. #3
    Senior Member
    Join Date
    Sep 2006
    Location
    San Jose
    Posts
    846
    I've seen this before and often wondered about it. Doesn't this have to come from the suspension shrinking up or a long time DC bias which I'm inclined to think would probably fry the coil. This was intended more as a question than the answer.

  4. #4
    Senior Señor boputnam's Avatar
    Join Date
    Apr 2003
    Location
    northern california
    Posts
    6,142
    Well the 2226 has a pleated surround and is "relatively" new - that's why I was hoping for some pics.

    I don't own any, but the 2226H have a natural position where the surround descends slightly from the basket edge. I don't know if the spider is "flat" in rest position...
    Attached Images Attached Images  
    bo

    "Indeed, not!!"

  5. #5
    Senior Señor boputnam's Avatar
    Join Date
    Apr 2003
    Location
    northern california
    Posts
    6,142
    This recent eBay is clearly a recone with non-OEM kit - note the:
    - oversized dust cover
    - four instead of three pleats
    - lack of exposed leads (TOP pic)

    ... all as compared to the stock design (BOTTOM pic)...
    Attached Images Attached Images   
    bo

    "Indeed, not!!"

  6. #6
    Senior Member spwal's Avatar
    Join Date
    Dec 2006
    Location
    Boston
    Posts
    571
    Hi,

    is this something to be concered about with the Model 19 speakers?

    How would i know if the cones are sagging? I think these might have been sitting for a long time.

    thanks

    sean

  7. #7
    Senior Member
    Join Date
    Apr 2003
    Location
    Winnipeg Manitoba Canada
    Posts
    2,291
    Quote Originally Posted by spwal View Post
    Hi,

    is this something to be concered about with the Model 19 speakers?

    How would i know if the cones are sagging? I think these might have been sitting for a long time.

    thanks

    sean
    I do not think you have any thing to worry about. My 19,s are 28 years old and there is no cone sag.

  8. #8
    RE: Member when? subwoof's Avatar
    Join Date
    Aug 2003
    Location
    fingerlakes region, NY
    Posts
    1,899

    offset priorities

    One of the major contributors to this kind of offset is the actual waveform being presented to the speaker AND the box tunng relationship. A good tutorial on this is in the crown MA5002 operartion manual. Crown incorporated a switch on this high power amp to specificly correct this common cause of premature cone failure at *high* excursions.

    When the "average" center position of the cone is negative, the cone will eventually develop a "sinking" cone. The same applies for the positive.

    I have seen many of these over the years and the most common problem is when the speaker is used BELOW the actual tuning design of the cabinet ( or is in a homemade cab with incorrect tuning ) which causes the cone to "unload"

    The only cure for this is a recone. A new cone will give you 2007 glues and materials that are superior to the ( possibly ) 1987 one you bought. A dead give away is the color of the lead wires. previous to 1992 they were copper and they had some issues.
    sub

  9. #9
    Senior Member
    Join Date
    Sep 2006
    Location
    San Jose
    Posts
    846
    I'm not taking issue with that, just questioning it. Using speakers not properly loaded can certainly wear them out but, I believe, that this should be neutral position wise. The signal you normally feed them should push the cone away from and pull the cone towards the magnet equally to the best of my knowledge, barring DC offset. And, you don't get away with much DC offset without frying voice coils. Many a nam vet who brought home a Sansui 2000 can attest to that. I'm running on general knowledge and mechanical principle here not really specific expertise so if I'm full of shit straighten me out.

  10. #10
    jim henderson
    Guest
    Here's a pic.
    Attached Images Attached Images  

  11. #11
    Senior Señor boputnam's Avatar
    Join Date
    Apr 2003
    Location
    northern california
    Posts
    6,142
    By itself, that doesn't look "wrong". Since your post I checked all the pics I have of pleated surround woofs, and most/all look like that. My 2242's are buried deepest in the trailer so can't check them. But, here's a picture of the edge from the brochure - clearly looks like yours.

    Why do you suspect there is a problem?
    Attached Images Attached Images  
    bo

    "Indeed, not!!"

  12. #12
    Dang. Amateur speakerdave's Avatar
    Join Date
    May 2003
    Location
    Northern California
    Posts
    3,734
    Quote Originally Posted by Thom View Post
    The signal you normally feed them should push the cone away from and pull the cone towards the magnet equally to the best of my knowledge, barring DC offset.
    Not true. Music is not made of sine waves, sharp transients least of all. Initial half cycles of sounds are generally positive and generally stronger, the extent of that depending on what is making it.

    If subwoof is correct, the sucked in cones result from long hard use with the total system reproductive chain 180 degrees out of absolute phase.

    Speculating here: the back slant of surrounds, which I have also observed, may be created by design to absorb those positive transients without mechanical damage, and the voice coil is centered with that backslant.

    David

  13. #13
    RE: Member when? subwoof's Avatar
    Join Date
    Aug 2003
    Location
    fingerlakes region, NY
    Posts
    1,899

    It's the spider, man

    Look at the spider from the side when the speaker is sitting on a table face up..

    The tops ALL should be even and parallel with the table. A *tiny* sag is sometimes seen with the foam surround models ( esp the 18" 2245 ) but the rolled cloth types should not.

    The voice coil is MUCH deeper than the coil gap so the only real disadvantage of an offset is the limited Xmax and of course, the possibility the speaker will bottom out when driven hard.

    sub

  14. #14
    Junior Member
    Join Date
    Dec 2006
    Location
    usa
    Posts
    7

    Fix by playing in phase?

    "If subwoof is correct, the sucked in cones result from long hard use with the total system reproductive chain 180 degrees out of absolute phase."

    So, play them hard, in phase to correct the offset? And make sure the music you play has lots of transients with correct, natural, absolute phase.

  15. #15
    Dang. Amateur speakerdave's Avatar
    Join Date
    May 2003
    Location
    Northern California
    Posts
    3,734
    I thought that question was already answered in post #8, but I suppose you could try it and let us know.

    David

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Repairing weak spot in 2242hpl cone
    By KenWH in forum Lansing Product Technical Help
    Replies: 11
    Last Post: 06-30-2006, 11:08 AM
  2. 128H-1 Cone required (blown V/C OK)
    By Anthony L100 in forum Lansing Product DIY Forum
    Replies: 3
    Last Post: 03-09-2006, 04:31 PM
  3. E 145 cone changes
    By franz in forum Lansing Product General Information
    Replies: 2
    Last Post: 08-03-2005, 01:13 PM
  4. LE 14C Cone
    By banker80 in forum Lansing Product General Information
    Replies: 0
    Last Post: 05-26-2004, 06:30 AM
  5. 2245 cone questions
    By Phil Jeffery in forum Lansing Product Technical Help
    Replies: 12
    Last Post: 12-09-2003, 08:02 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
  •