Sub1500 problem

[Eaulive]

Yes you gain something running bridged. One xlr cable and power cable each to be used elsewhere.

Right! Can't argue with that

[toddalin]

He ripped the coils off of the cones! That means they were trying to exceed xmax... as you must know these things are thunderously loud at high power levels. It can be hard to tell if that god awful racket is the cone tearing or your house protesting as the drywall is bending and flexing, the floor creaking, windows and doors rattling etc.

Widget

Or perhaps everything was within the max excursion limitations until the spider pulled away, then all he11 broke loose.

[maxwedge]

Or perhaps everything was within the max excursion limitations until the spider pulled away, then all he11 broke loose.

This separation of the cone and spider is not new.
http://www.audioheritage.org/vbullet...hread.php?8281

[toddalin]

This separation of the cone and spider is not new.
http://www.audioheritage.org/vbullet...hread.php?8281

I understand that the separation issue is not new.

I'm just saying that perhaps your voice coil didn't jump out out the gap until the spider separation occured and that the occurance may have happened within the normal xmax limits. When the spider lets go, there is less tension holding the coil in the gap so it can jump out at less than the speced xmax input.

I've always had the cones slap the magnets with an audible "thunk" before a cone gets far enough out of the gap on AlNiCo JBLs and the W15GTi takes it all in stride without a complaint.

[maxwedge]

I'm just saying that perhaps your voice coil didn't jump out out the gap until the spider separation occured and that the occurance may have happened within the normal xmax limits. When the spider lets go, there is less tension holding the coil in the gap so it can jump out at less than the speced xmax input.

I agree with you and I believe that damage that happened with my 2 sub1500's is a combination of user abuse, intentional or not, and defects in the gluing of the spider.

To recap: in 2005 these went from Idle to max power instantly (can't remember the program type, most likely a sine wave signal) with 1500 watts. Grabbed the sliders on the mixing board as fast as I could and pulled them down. After that I had lots of voice coil rub at low volumes in one of the subs (the one in the pics here). I pulled this speaker out and found that the spider was loose from the basket a bit more that 3/4 the dia.

I glued that spider down and inspected the other sub. The 2nd spider only lifted about 1/4 the dia max.

Reinstalled them and tested. The 1st sub1500 had some minor vc rub (I know, not acceptable!) at higher volumes and the 2nd one had no noise. I figured I didn't get the spider correct on the 1st and decided to live with it until it got worse.

Fast forward to 2010-11 and I got this new Marantz Pro-pre that has a much better subwoofer decoding that my old Yamaha. I was viewing Tron Legacy in Blu-Ray and the Lightcycle scene has some massive sub action. That 1st sub1500 came apart again in that scene.

I pulled it out and that's what you see in those pics of mine. My prior repair hadn't failed.
My other one is failing in the same manner but it hasn't ripped out like the 1st so I got some new super glue and I'm going to try to repair it but ultimately I will recone them as long as I can get the kits.

[maxwedge]

I gave it a shot this morning on my other Sub-1500. The 1st one has an open-circuit.
Didn't feel like waiting on an order for some Loctite 422 so I went down to a local auto body supply store and picked up a similar product by 3M. I'm going away this week end so I'm not going to be able to test it much. 3M says 12-24 hours for max strength.

I used some Bamboo skewers to hold open the gap, sprayed the primer in, let I sit a little and then used a syringe to apply the Cyanoacrylate adhesive pulling the skewers out as I went around.

The area around the leads separated from the cone and the rest from the spider.
the spider is not torn at all.



In the pic below look in the center of the glue bead and you see a crack in the original glue.
There are many of these cracks in the glue beads on both speakers.

The syringe came from one of those sinus kits for spraying a solution up the nose!

[grumpy]

Here's to hoping it holds better than the original
...sure looked like a pure adhesive failure (too brittle for the application?)

[maxwedge]

Here's to hoping it holds better than the original
...sure looked like a pure adhesive failure (too brittle for the application?)

Thanks grumpy. Yes it looks very brittle and there's no way I can remove the original adhesive.

I applied the adhesive around 10am and it still hasn't cured and according to this article I quote here, I need to go do some heavy breathing on my speaker!

Cyanoacrylate glue is the technical term for glues with brand names like Crazy Glue, Super Glue or Insta-Bond. It is a catch-all term for quick bonding super glues that are used in fixing or combining plastics to other materials like wood or metal.
Cyanoacrylate glue is an acrylic resin, which is vastly different from the traditional adhesives like water based glues. An acrylic resin would usually be composed of two different and separate liquids -- one that is poured into the mold, while the other is used sparingly for the purpose of making it a hardener. In cyanoacrylate glues, the hardener that is used is water.
The main ingredient in cyanoacrylate is, of course, cyanoacrylate. This type of glue, if placed on a dry surface or on certain plastics will not form a bond with the surface. But if the slightest amount of water is introduced – and this includes moisture from the air – the molecules of the glue will undergo a chemical reaction and form a tight chain between the two surfaces that will be bonded. This chemical reaction will happen seconds after the water and cyanoacrylate come into contact. Traditional glues will depend on evaporation to form a bond. But a cyanoacrylate glue will actually generate heat to help in the curing process.
There are some users of cyanoacrylate glue that get frustrated because they can’t achieve a bond that they need. But this happens if there is a lack of moisture or if the materials are non porous. A thin layer of water introduced to the bond, or even breathing on the material may introduce enough moisture to produce a stronger bond.

[maxwedge]

The SUB1500 I just tried to repair still has issues.
At low volumes there are no problems at all but in extreme LFE sections of movies it sounds like the voice coil (former?) is bottoming out. I've pulled it out and rechecked my glue job and it is holding. I used one section of the movie Tron to set the sub level and I had to back down the level on my Marantz to the max, -12db, and back down the sensitivity on the amp quite a bit to the point where the speaker stops acting up.

So I'm in limp mode...

Anyway, can someone in the repair profession tell me if the kits are are available?
The number is C4RSUB1500

Thanks
Scott

[4313B]

Yes, they are available. You might want to contact Edgewound and see if he'll recone it for you.

[maxwedge]

Thank you for that info and I would love to use Edgewound but he's a long ways from me so
I was planing on using Daniel at AUDIVEX in Berkeley. He tried to find some info on the kit but couldn't find anything and then I called up JBL Consumer and that was some joke! The guy at JBL had no clue and sounded like he didn't even want to bother to figure out how to get the kit!

[rdgrimes]

The phone techs at JBL Pro are much more smarter and easier to deal with.

[Mr. Widget]

Thank you for that info and I would love to use Edgewound but he's a long ways from me so
I was planing on using Daniel at AUDIVEX in Berkeley. He tried to find some info on the kit but couldn't find anything and then I called up JBL Consumer and that was some joke! The guy at JBL had no clue and sounded like he didn't even want to bother to figure out how to get the kit!

I would second 4313B's suggestion. Sometime back Zilch asked Daniel to help out with a blown Sub1500... he couldn't get the kit. Edge called his contacts at JBL and was successful I believe.


Widget

[maxwedge]

The phone techs at JBL Pro are much more smarter and easier to deal with.

Yeah but the Sub1500 is a consumer department product (spec dept) as I understand so that is why I called them.

[maxwedge]

I would second 4313B's suggestion. Sometime back Zilch asked Daniel to help out with a blown Sub1500... he couldn't get the kit. Edge called his contacts at JBL and was successful I believe.


Widget

Alright, looks like I'll need to plan a trip to Disneyland to keep the family happy.