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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Subwoofer Forum => Topic started by: Mat Allen on October 04, 2012, 04:50:04 PM

Title: Fixing a tear...
Post by: Mat Allen on October 04, 2012, 04:50:04 PM
So, I’ve had this speaker for a while now and recently got the inspiration to try and fix the tears in it. What would be the best way to go about this? The first cut is about 1/4” while the other is 1/2”. Do I need to take special precautions because they’re on the folds?

Thanks!
Title: Re: Fixing a tear...
Post by: Paul G. OBrien on October 05, 2012, 10:56:03 AM
Do I need to take special precautions because they’re on the folds?  Thanks!

Yes that's the suspension so whatever you apply has to remain flexible when dry. For those I suggest rubber cement like that used to patch a hole in a bicycle tire, just apply some cement to the back of the cut and smooth it to follow the contours of the suspension. I suggest the back because this type glue has a shiny finish that will stand out on the front surface.
Title: Re: Fixing a tear...
Post by: Mat Allen on October 05, 2012, 03:58:19 PM
Would I be able to use another type of glue for the front(in addition to the back) for extra durability or is it not necessarily needed?
Title: Re: Fixing a tear...
Post by: Paul G. OBrien on October 05, 2012, 05:27:40 PM
Those dings look to be pretty small overall so I don't see adding some at the front being necessary but then it won't hurt much either, you may get some squeezing through to the front anyway which you'll have to smooth out so you may end up coating both sides regardless. Strength takes a back seat to looks here but you also don't want to create a situation where the suspension binds and pulls the VC off center either, so whatever you do try to use the minimum amount of glue possible to plug the holes and minimize further fabric tearing.
Title: Re: Fixing a tear...
Post by: Mat Allen on October 05, 2012, 09:52:21 PM
Sorry, I’m not too familiar with the anatomy of subs or speakers in general. VC? Thanks for the help by the way.
Title: Re: Fixing a tear...
Post by: Ian Murphy on October 05, 2012, 10:13:46 PM
I believe he means voice coil, its the coil of wire that creates a magnetic field to drive the cone: http://en.wikipedia.org/wiki/Voice_coil.  If the voice coil isn't centered properly the speaker is essentially screwed and will rub against the surrounding magnet structure.
Title: Re: Fixing a tear...
Post by: Mat Allen on October 05, 2012, 10:21:14 PM
Ok, thanks. What are the best sites or books to learn about what’s what?
Title: Re: Fixing a tear...
Post by: Stu McDoniel on October 11, 2012, 08:47:59 PM
So, I’ve had this speaker for a while now and recently got the inspiration to try and fix the tears in it. What would be the best way to go about this? The first cut is about 1/4” while the other is 1/2”. Do I need to take special precautions because they’re on the folds?

Thanks!
Adding glue or doping or rubber cement affects the compliance.  I looked at that pic and thought to myself...leave it alone.  That dosnt look like anything you need to be concerned with in my opinion.  You want equal forces on the entire circumference of that cone/suspension.  Adding goop to the suspension in one spot will change that.
Title: Re: Fixing a tear...
Post by: joelee on November 12, 2012, 04:58:51 AM
So, I’ve had this speaker for a while now and recently got the inspiration to try and fix the tears in it. What would be the best way to go about this? The first cut is about 1/4” while the other is 1/2”. Do I need to take special precautions because they’re on the folds?

Thanks!

i saw the tears on the spider, i suggest let them be. if you glue them, it will affect the flexibility and elasticity, in consequence, you will speed the damage.
Title: Re: Fixing a tear...
Post by: Ivan Beaver on November 12, 2012, 07:24:29 AM
Adding glue or doping or rubber cement affects the compliance.  I looked at that pic and thought to myself...leave it alone.  That dosnt look like anything you need to be concerned with in my opinion.  You want equal forces on the entire circumference of that cone/suspension.  Adding goop to the suspension in one spot will change that.
Personally I would smear a little bit of silicon rubber on both sides of the tear.  Don't goop it on, but cover well.

You have to choose between 2 evils.  Yes the added weight will affect the suspension a little bit. 

HOWEVER the tear is acting as an air leak.  And that may be more of an issue than a small change the the suspension.

Also if it is not fixed-there is a good chance it will get worse and be harder to fix later.

Of course the proper repair is to have it reconed-or possibly have a new surround installed.

But if it were my speaker-in the current condition-I would use silicon rubber and be done with it.
Title: Re: Fixing a tear...
Post by: Ivan Beaver on November 12, 2012, 07:25:59 AM
i saw the tears on the spider, i suggest let them be. if you glue them, it will affect the flexibility and elasticity, in consequence, you will speed the damage.
I didn't see any photos of the spider-so there may be more damage than what we are aware of.

If the spider is also damaged-then a recone is in order.
Title: Re: Fixing a tear...
Post by: Travis_Valois on November 12, 2012, 07:05:15 PM
A section of material from a pair of women's pantyhose, and contact cement.
Title: Re: Fixing a tear...
Post by: joelee on November 15, 2012, 04:05:48 AM
I didn't see any photos of the spider-so there may be more damage than what we are aware of.

If the spider is also damaged-then a recone is in order.

I made a mistake to describe it, but i don't know how you call the side "material" alike spider of the paper cone.
Yes, if spider damaged, it's easy to replace a new.
Title: Re: Fixing a tear...
Post by: Ivan Beaver on November 15, 2012, 07:51:08 AM
I made a mistake to describe it, but i don't know how you call the side "material" alike spider of the paper cone.
Yes, if spider damaged, it's easy to replace a new.
The spider is MUCH harder to replace than the surround (which is the tear in question).  If you are going to try to "replace" a spider-you are much better off doing a full recone.

However replacing the surround is not a big deal-I used to do that all the time (when I was a reconer) for various rips and tears-and it was cheaper than a full recone.

Of course you have to have the skill and knowledge of how to do it properly-or the speaker will end up worse than when it started.