Hope someone can give me some advice on which glue to use when glueing a rubber surround to a steel casket. I bought a pair of these audax 10inchers 89 and they have been laying in my closet since then... Well seems as if they've come unglued! It will probably be diffecult to get the voicecoil centered again as the cone is sagging somewhat. How important is this when using the driver in a subwoofer?
/Niclas
Here's a picture to illustrate my situation:
/Niclas
Here's a picture to illustrate my situation:
Attachments
Centering is quite important. But if the surround has only come loose in that one spot, you might be OK. Try gluing it back down with contact cement, then carefully push it through its excursion range (spacing your fingers equally around the cone for balance). See if it rubs. If not, then try it on some sine waves. If it does rub, you'll need to remove the dust cap and the surround, shim the voice coil, then reglue the surround.
With contact cement, the trick is to apply it to both surfaces, let it dry, and only then bring the surfaces together.
With contact cement, the trick is to apply it to both surfaces, let it dry, and only then bring the surfaces together.
shimming
What this does is to mechanically force the coil to be centered. You take some shim stock, which is like foil of a known thickness (check with Audax on what the gap should be; shim stock is available from a variety of sources and can be plastic, brass, or steel) and insert it between the coil and magnet or pole piece. Usually, you'll use three or four pieces spaced around the coil so that the coil is forced to center. Then the surround is glued in place.
After it's dry, remove the shims and glue on a replacement dust cap. If Audax doesn't give you a gap size, then you can trial and error it by using thin shim stock and stacking it; IOW, if three or four stacks of two pieces each still doesn't immobilize the cone, go to three pieces. And so on. Hope this is clear- this is a tough one to describe without using my hands
To find shim stock, check with companies that supply machine shops.
What this does is to mechanically force the coil to be centered. You take some shim stock, which is like foil of a known thickness (check with Audax on what the gap should be; shim stock is available from a variety of sources and can be plastic, brass, or steel) and insert it between the coil and magnet or pole piece. Usually, you'll use three or four pieces spaced around the coil so that the coil is forced to center. Then the surround is glued in place.
After it's dry, remove the shims and glue on a replacement dust cap. If Audax doesn't give you a gap size, then you can trial and error it by using thin shim stock and stacking it; IOW, if three or four stacks of two pieces each still doesn't immobilize the cone, go to three pieces. And so on. Hope this is clear- this is a tough one to describe without using my hands
To find shim stock, check with companies that supply machine shops.
Shim stock
PAper is the cheapest type of shim stock. Business cards playing cards thick card board normal paper. They will all work out and they are cheap and easily available. You just need a way to measure them. Buy beg borrow a micrometer and go to it. Adventures in reconing are the beginning of great things.
Mark
PAper is the cheapest type of shim stock. Business cards playing cards thick card board normal paper. They will all work out and they are cheap and easily available. You just need a way to measure them. Buy beg borrow a micrometer and go to it. Adventures in reconing are the beginning of great things.
Mark
Thanks for all the advice!
I may try the easy way out and just glue the surround on partially (say 3 evenly spaced positions) and see what happens. If I don't hear any unwanted noise I'll glue the whole thing back on. Since I haven't heard them before I'm not sure it will be worth the bother of sending them in for professionall help.
karma wrote:
PS: Fred, don't change, ever!
I may try the easy way out and just glue the surround on partially (say 3 evenly spaced positions) and see what happens. If I don't hear any unwanted noise I'll glue the whole thing back on. Since I haven't heard them before I'm not sure it will be worth the bother of sending them in for professionall help.
karma wrote:
Face up. Although one was on top of the other causing its spider to be (de)pressed.
PS: Fred, don't change, ever!
Attachments
Have a look at this PDF for some instructions.
http://www.speakerbits.com/net/resources/pdf/gen_refm.pdf
For shimming I find a clear plastic (an acrylic?) that is used for the cover page when binding documents ideal. It's 0.2mm thick, quite stiff but flexible, nice and slippery so it doesn't get stuck and doesn't tear. Tip.....cut the corners of the shim at 45 degrees x 10mm which makes it so much easier to insert.
A water based contact adhesive is ideal for gluing.
http://www.speakerbits.com/net/resources/pdf/gen_refm.pdf
For shimming I find a clear plastic (an acrylic?) that is used for the cover page when binding documents ideal. It's 0.2mm thick, quite stiff but flexible, nice and slippery so it doesn't get stuck and doesn't tear. Tip.....cut the corners of the shim at 45 degrees x 10mm which makes it so much easier to insert.
A water based contact adhesive is ideal for gluing.
you could use loctite there are quite a few types of rubber to metal glues from loctite
to be sure you could use loctite prism gel ,
only if need to shim the voice coil , you can increase the efficiency of the glueing by rolling the rubber inside out gently so that the fixing part faces you
gently , tenderly - emery paper / sand / roughen the surface of the rubber to be glued on to the chasis
this helps in glueing speacially in cured rubber products , like a surround
next to shim or not to shim
if you can remove the dustcap dexterly its best to shim
mark the perimeter of your dust cap with a pencli and remove the dust cap
do not supply any source to your driver and check with a magnifying glass if the voice coil inners is touching any surface - if not press the cone and check
if all seems ok
cut up
(like advised in a previous thread any slippery thin material from cards to acrilyc , one house hold item would be a used photo film)
in straight 6 to 10 mm bits about 1 1/2 to 2 inch in length and cut one side edges in a _ V
insert these bits between the polepiece and the voice coil
inserting sequence should be
the second bit goes opposite the first one not next to it
that is when you have 2 bits in they shoul be facing one another
after you have shimmed the voice coil
you can proceed to glue the surround , allow for setting time
once the glue is set
with a gripper piler gently remove all the bits inserted in the v/c
replace the dustcap with referance to the pencil marking made before removing
though it may sound a bit complex its fairly easy and should take you an haur or so
suranjan
transducer design engineer
to be sure you could use loctite prism gel ,
only if need to shim the voice coil , you can increase the efficiency of the glueing by rolling the rubber inside out gently so that the fixing part faces you
gently , tenderly - emery paper / sand / roughen the surface of the rubber to be glued on to the chasis
this helps in glueing speacially in cured rubber products , like a surround
next to shim or not to shim
if you can remove the dustcap dexterly its best to shim
mark the perimeter of your dust cap with a pencli and remove the dust cap
do not supply any source to your driver and check with a magnifying glass if the voice coil inners is touching any surface - if not press the cone and check
if all seems ok
cut up
(like advised in a previous thread any slippery thin material from cards to acrilyc , one house hold item would be a used photo film)
in straight 6 to 10 mm bits about 1 1/2 to 2 inch in length and cut one side edges in a _ V
insert these bits between the polepiece and the voice coil
inserting sequence should be
the second bit goes opposite the first one not next to it
that is when you have 2 bits in they shoul be facing one another
after you have shimmed the voice coil
you can proceed to glue the surround , allow for setting time
once the glue is set
with a gripper piler gently remove all the bits inserted in the v/c
replace the dustcap with referance to the pencil marking made before removing
though it may sound a bit complex its fairly easy and should take you an haur or so
suranjan
transducer design engineer
hi
this is the type of dust cap you need for below 100 hz
it should be a felpted type soft to tuch and your nails should sink in easily when you press the surface
do not go for a very hard dustcap - though it provides rigidity to the cone and prevents cone break up (refering to distortion from cone break - up - mode) , speacially if you are using a passive cross - over
if you are using an active cross over ( 4 th order or so )
then you can go for a stiff dust cap without a problem
since i am in india i dont think i can advise on where you could get the dustcaps
on my trips to europe , i found italy and greece having shops which repair speakers , even was surprised by seeing quite a few indian replacement cones etc being used !
if you can buy a woofer which is scrap and open one from that
to open apply amyl acetate and leave for some time and then prise it open
suranjan
this is the type of dust cap you need for below 100 hz
it should be a felpted type soft to tuch and your nails should sink in easily when you press the surface
do not go for a very hard dustcap - though it provides rigidity to the cone and prevents cone break up (refering to distortion from cone break - up - mode) , speacially if you are using a passive cross - over
if you are using an active cross over ( 4 th order or so )
then you can go for a stiff dust cap without a problem
since i am in india i dont think i can advise on where you could get the dustcaps
on my trips to europe , i found italy and greece having shops which repair speakers , even was surprised by seeing quite a few indian replacement cones etc being used !
if you can buy a woofer which is scrap and open one from that
to open apply amyl acetate and leave for some time and then prise it open
suranjan
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