jt45
Super Member
Here are a few pics of my latest Midrange repair. These are IMO a major
PITA to work on. A few things you might find that come in handy when repairing these.
1. Exacto Knife
2. Very small jewelers screwsriver (flat tip) It comes in very handy cleaning out those channels in the faceplate.
3. Straight pin or needle
4. Magnified Light
5. Soldering Iron with a small tip
6. Meter for testing
7. Good eyes (I kinda failed on this one) or just wing it.
There are 2 methods that I have used to repair these. The first method
is to solder a bridge wire across the break (provided you can find it without
causing another break).
The second method is to remove all the exposed tinsel wire and coating back to the voice coil and use 1 wrap of (Fresh) tinsel wire off of the Voice coil and retrace it back to the solder points of the Connectors.
In these pictures I will be using the second method because I believe it will last longer and doesn't require any tricky bridge wire soldering. Its a tedious job and anyone trying this should practice on a expendable driver before
trying it with a good one.
First up a pic of the victim (tested open)
The first thing I do is remove all the old Tinsel Wire and coating from the Solder points back to the dome. I use the exacto knife and the jewelers screwdriver for this part.
Then remove the 4 faceplace screws (be sure to mark the position of the Faceplate/Dome in relation to the Magnet). Take off the faceplate and flip it over, you should be able to see the voice coil with the tinsel wire wrapped.
At this point I go ahead remove the Glued parts of old tinsel wire on the backside of the dome. (Its not easy to seperate it from the cloth dome)
This is the part where it gets tricky, I usually use a pin or needle to open
a tiny channel right where it runs between the dome and Voice coil (use caution here because if you punch through too hard you can damage the voice coil (bend it). Now I slowly pull 1 wrap off the coil and retrace it back thru the hole I made with the needle to the inside of the dome. I use one wrap from the top and one wrap from the bottom of the Tinsel wire.
Thread the tinsel wire back through the dome, at this point I add a dab of glue inside the dome like the original wire had to secure it to the cloth and let that dry before moving on to the next step.
Then I cut off the tinsel wire at the right length to make the solder point but still provide room for the wire to move. Before soldering you MUST scrape off
the coating on the tinsel wire or you wont get a reading.
Notice how the last 1/4 inch is copper and not red like the coating.
I used a black adhesive that dries tacky to coat the wire and seal the channel, Im still searching for the right type of glue or silicone and a smaller
method of applying it. Maybe a syringe type applicator with a small tip ! I know this would be helpfull in making a neater job.
Here is the final pics of the working driver. I usually get a slightly lower reading on the meter from 7.2 down to 6.9 ohms seems to be the norm
when using those new tinsel wire wraps from the voice coil. I cannot hear a difference in their performance though.
Hope this helps someone !
JT
PITA to work on. A few things you might find that come in handy when repairing these.
1. Exacto Knife
2. Very small jewelers screwsriver (flat tip) It comes in very handy cleaning out those channels in the faceplate.
3. Straight pin or needle
4. Magnified Light
5. Soldering Iron with a small tip
6. Meter for testing
7. Good eyes (I kinda failed on this one) or just wing it.
There are 2 methods that I have used to repair these. The first method
is to solder a bridge wire across the break (provided you can find it without
causing another break).
The second method is to remove all the exposed tinsel wire and coating back to the voice coil and use 1 wrap of (Fresh) tinsel wire off of the Voice coil and retrace it back to the solder points of the Connectors.
In these pictures I will be using the second method because I believe it will last longer and doesn't require any tricky bridge wire soldering. Its a tedious job and anyone trying this should practice on a expendable driver before
trying it with a good one.
First up a pic of the victim (tested open)
The first thing I do is remove all the old Tinsel Wire and coating from the Solder points back to the dome. I use the exacto knife and the jewelers screwdriver for this part.
Then remove the 4 faceplace screws (be sure to mark the position of the Faceplate/Dome in relation to the Magnet). Take off the faceplate and flip it over, you should be able to see the voice coil with the tinsel wire wrapped.
At this point I go ahead remove the Glued parts of old tinsel wire on the backside of the dome. (Its not easy to seperate it from the cloth dome)
This is the part where it gets tricky, I usually use a pin or needle to open
a tiny channel right where it runs between the dome and Voice coil (use caution here because if you punch through too hard you can damage the voice coil (bend it). Now I slowly pull 1 wrap off the coil and retrace it back thru the hole I made with the needle to the inside of the dome. I use one wrap from the top and one wrap from the bottom of the Tinsel wire.
Thread the tinsel wire back through the dome, at this point I add a dab of glue inside the dome like the original wire had to secure it to the cloth and let that dry before moving on to the next step.
Then I cut off the tinsel wire at the right length to make the solder point but still provide room for the wire to move. Before soldering you MUST scrape off
the coating on the tinsel wire or you wont get a reading.
Notice how the last 1/4 inch is copper and not red like the coating.
I used a black adhesive that dries tacky to coat the wire and seal the channel, Im still searching for the right type of glue or silicone and a smaller
method of applying it. Maybe a syringe type applicator with a small tip ! I know this would be helpfull in making a neater job.
Here is the final pics of the working driver. I usually get a slightly lower reading on the meter from 7.2 down to 6.9 ohms seems to be the norm
when using those new tinsel wire wraps from the voice coil. I cannot hear a difference in their performance though.
Hope this helps someone !
JT