Results 1 to 14 of 14

Thread: "New" L56's have a problem.

  1. #1
    Senior Member rdgrimes's Avatar
    Join Date
    Aug 2008
    Location
    New Mexico, USA
    Posts
    2,166

    "New" L56's have a problem.

    Hey, just received a pair of L56's, http://cgi.ebay.com/ws/eBayISAPI.dll...m=330264330851

    These are nearly flawless cabs and grills. Look like they are a year old. The 188H woofers still have the original surrounds, which look OK but feel kind of brittle and "thin". If you're not aware, these have the 034 tweets, XO at 2.2K, which is too low for the 034. (The L46 has a 3K XO, the L15 has a 2.5K XO.)

    Anyway, there some significant distortion in the mids when I crank up the power. Right about where vocals or a piano would be. Driving them with a Carver M 500t (250 WPC). At lower volume, they sound fine, though you can hear the 034s struggling at times. I can pretty much narrow it down to one of the 188Hs, and once it starts it keeps doing it for a bit. There's no rubbing or scraping in the driver when I push on the dust cover. It really does sound like a physical issue and I can actually see the cone vibrating. The offending driver does feel a little softer to push on than the other one.

    So I'm wondering if this could be the surround, or if the XO might be at fault. It's clearly not a good sound. The drivers all sound great otherwise.

    In general, these are pretty nice sounding for a 2-way, though you can hear the mid-range hole. I'm looking forward to getting a pair of L46s, I expect them to be the best of the 2-ways.

  2. #2
    Senior Member SEAWOLF97's Avatar
    Join Date
    Jan 2006
    Location
    PDX, ®egon
    Posts
    9,074
    My L-56's are nearly perfect, but still not up to the sound of the L-26's...it is a good looking model, but I dont think they were great , even when new and perfect....the black plastic/foam surrounds must be ready to go by now (since they were produced 81-83), and wasnt impressed with the hf. maybe you are overpowering them ?? Dont recall a high handling capacity.

    that seems a record price..I see them needing foam on CL sometimes for $50-60

    http://www.audioheritage.org/vbullet...&postcount=104

    The L-40a also seemed superior.
    “If you think that’s the dumbest thing you’ve ever heard,
    just wait a couple minutes!”

  3. #3
    Senior Member rdgrimes's Avatar
    Join Date
    Aug 2008
    Location
    New Mexico, USA
    Posts
    2,166
    Not over-powered, and only one driver is doing it. The Carver is at less than 100w when it happens. (<10W average on the meters). I've heard surrounds cause popping and crackling on bass, but this is the first I've seen one sound like this. The cone looks like it's flapping in the breeze. Guess I'll add these to the "re-foam pile". About time to have a foaming party over here.

    Nothing wrong with the HF on these, it's just that the 188H is overpowering the 034. they just need some EQ to bring up the 034s.

    the coating on these surrounds is weird, it was sprayed on after they were attached to the cone. Almost looks like automotive undercoating.

  4. #4
    Senior Member SEAWOLF97's Avatar
    Join Date
    Jan 2006
    Location
    PDX, ®egon
    Posts
    9,074
    Quote Originally Posted by rdgrimes View Post
    the coating on these surrounds is weird, it was sprayed on after they were attached to the cone. Almost looks like automotive undercoating.
    finally something we agree on ...see my post from the refoam job

    http://www.audioheritage.org/vbullet...&postcount=105

    its not sprayed on ...they shred, not crumble like foam
    “If you think that’s the dumbest thing you’ve ever heard,
    just wait a couple minutes!”

  5. #5
    Senior Member rdgrimes's Avatar
    Join Date
    Aug 2008
    Location
    New Mexico, USA
    Posts
    2,166
    Quote Originally Posted by SEAWOLF97 View Post
    finally something we agree on ...see my post from the refoam job

    http://www.audioheritage.org/vbullet...&postcount=105

    its not sprayed on ...they shred, not crumble like foam
    The coating on these is clearly sprayed on, I can see the over-spray on the white cones for about 1/16" inward from the outer edge of the cone.

  6. #6
    Senior Member SMKSoundPro's Avatar
    Join Date
    Apr 2005
    Location
    Anchorage, Alaska
    Posts
    1,031
    I have l56's in the living room. I removed the butyl rubber and refoamed using a 125 foam ring. Worked like a champ.

    You mention a "188h" woofer, should be a 118h. No cone kits available to my knowledge.

    Also check for a loose spider glue joint. They Xmax (excurt?) quite a bit when the surround stops holding the cone in. Might have a spider lifting.

    They are fine for what they are. Nothing like my L110's in my workshop office, though. Same size, but completely different.

    Scotty.
    One step above: "Two Tin Cans and a String!"
    Longtime Alaskan Low-Fi Guy - E=MC² ±3db

  7. #7
    Senior Member rdgrimes's Avatar
    Join Date
    Aug 2008
    Location
    New Mexico, USA
    Posts
    2,166
    Quote Originally Posted by SMKSoundPro View Post
    I have l56's in the living room. I removed the butyl rubber and refoamed using a 125 foam ring. Worked like a champ.

    You mention a "188h" woofer, should be a 118h. No cone kits available to my knowledge.

    Also check for a loose spider glue joint. They Xmax (excurt?) quite a bit when the surround stops holding the cone in. Might have a spider lifting.

    They are fine for what they are. Nothing like my L110's in my workshop office, though. Same size, but completely different.

    Scotty.
    Meant 118, types 188.

    OK, I'll bite, WTF is a "spider joint"? Where do I find it?

  8. #8
    Senior Member SMKSoundPro's Avatar
    Join Date
    Apr 2005
    Location
    Anchorage, Alaska
    Posts
    1,031
    Note: screwdriver is pointing to the spider to frame glue joint. After time, this joint can fail causing a flapping or fluttering sound. A little spot of recone glue can fix it.

    Scotty.
    Attached Images Attached Images   
    One step above: "Two Tin Cans and a String!"
    Longtime Alaskan Low-Fi Guy - E=MC² ±3db

  9. #9
    Senior Member
    Join Date
    Apr 2003
    Location
    Winnipeg Manitoba Canada
    Posts
    2,301
    Did you tell the seller of your surprise?

  10. #10
    Senior Member rdgrimes's Avatar
    Join Date
    Aug 2008
    Location
    New Mexico, USA
    Posts
    2,166
    Quote Originally Posted by SMKSoundPro View Post
    Note: screwdriver is pointing to the spider to frame glue joint. After time, this joint can fail causing a flapping or fluttering sound. A little spot of recone glue can fix it.

    Scotty.
    Ordered the re-foam kit and will check this out. THANKS!

  11. #11
    Senior Member rdgrimes's Avatar
    Join Date
    Aug 2008
    Location
    New Mexico, USA
    Posts
    2,166
    Quote Originally Posted by SMKSoundPro View Post
    Note: screwdriver is pointing to the spider to frame glue joint. After time, this joint can fail causing a flapping or fluttering sound. A little spot of recone glue can fix it.

    Scotty.
    It all looks good. Measured 5.8u on the coil, which is right on spec. Boy, these are some lightweight drivers compared to what I'm used to. No model number on it, just a stencil of "2082" on the frame, and "72" in a circle. Is this a 118H?

    The surrounds are really floppy, I don't see any foam in them at all, just the rubbery film itself.

  12. #12
    Senior Member SMKSoundPro's Avatar
    Join Date
    Apr 2005
    Location
    Anchorage, Alaska
    Posts
    1,031
    I'll take a better picture of the basket and post when I get to work.

    Yes, it is a very light weight driver when compared to other JBL woofs.

    Yes, the cone is very floppy with the butyl rubber surrounds. I know of no replacement surrounds, so I used foam rings for a JBL 125 woofer. Seems to work fine.

    Please remember that these cabs are not what I would call super-duper hifi. They are what they are. I bought the pair I have from a pawn shop in 1990 and gave them to my new girlfriend, now wife, for her little GE combo stereo unit that pumped a whole 5 watts per channel! They were good enough for her jazzercize tapes. She has an emotional attachment to them. They are fine for our small living room TV, where most everything comes out the center channel.

    Re-foamed, they will work just fine. They are MANY other JBL bookshelf size speakers I would consider far superior to these L56's. (L-96, L110...)

    Also, If you plan on using them and loving them, find some 034 tweeters wherever you can, and save for spares. You'll need them. (034 diaphragms NLA)

    Scotty.
    One step above: "Two Tin Cans and a String!"
    Longtime Alaskan Low-Fi Guy - E=MC² ±3db

  13. #13
    Senior Member SMKSoundPro's Avatar
    Join Date
    Apr 2005
    Location
    Anchorage, Alaska
    Posts
    1,031
    When re-foaming, I very carefully slid a sharp razor knife under the dust cap without cutting into the cone.

    1. Shim the voice coil perfectly round using business cards, or some other plastic credit card gift cards.
    2. Then make sure the spider is sitting parallel to the horizon.
    3. Make sure the vc is centered.
    4. Glue on foam.
    5. Let sit and dry.
    6. Remove shims.
    7. Press gently on cone to assure no VC rubbing.
    8. Sweep with tone generator, or other test tone to assure proper operation.
    9. Re-glue on dust cap.
    10. Enjoy.

    Scotty.
    One step above: "Two Tin Cans and a String!"
    Longtime Alaskan Low-Fi Guy - E=MC² ±3db

  14. #14
    Senior Señor boputnam's Avatar
    Join Date
    Apr 2003
    Location
    northern california
    Posts
    7,007
    Quote Originally Posted by rdgrimes View Post
    Is this a 118H?

    The surrounds are really floppy, I don't see any foam in them at all, just the rubbery film itself.
    Can you post some pictures of the basket, and the cone face and surround edge? That would help.

    Follow Scotty's instructions. The shims are tricky. If you get a kit that includes a 30Hz tone CD, try using that before you remove the dust cap. This 30Hz CD can work excellent for centering the voicecoil and it avoids having to reglue the dust cap which can prove less than cosmetically pleasing for the inexperienced...

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. BGW 250 D Problem
    By allen mueller in forum Miscellaneous Gear
    Replies: 5
    Last Post: 01-19-2006, 05:30 PM
  2. problem posting attachments
    By Flodstroem in forum Forum Feedback
    Replies: 2
    Last Post: 03-19-2005, 04:06 PM
  3. B-460 subwoofer noise problem
    By johnhb in forum Lansing Product Technical Help
    Replies: 5
    Last Post: 01-28-2005, 11:20 AM
  4. 4344MKII and 275ND problem
    By spirou38 in forum Lansing Product Technical Help
    Replies: 24
    Last Post: 11-20-2004, 04:12 PM
  5. Problem with L300
    By boudu in forum Lansing Product General Information
    Replies: 39
    Last Post: 10-20-2003, 11:27 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
  •