A few months ago a customer brought me these speakers to work on:
But the catch is, the two woofers that need repair are inside the cabinet! How do you get to them?
Before you start make sure you have the right tools, you'll need quite a few for this project.
You need a 5/12" hollow-shafted socket driver, a #2 philips screwdriver, a pair of needle nose pliers, a normal pair of pliers, a of wire cutters, a wire stripper, a flat tool to pry, a hex driver or allen wrench, a soldering iron, solder, desolder wick.
Optional: plastic case to hold pieces
First, you must invert the speaker:
Remove the screws you find here, carefully pry the cover off, I used a flathead screwdriver.
You'll find fluff, remove this to reveal your first victim.
Voila!
Use your socket driver here to remove the four nuts:
You will also need to remove that center bolt. I didn't have a socket driver large enough for it so I carefully used needle nose pliers, this is a very long bolt so it takes some time.
It is not necessary but highly recommended to have some sort of container for all of the parts you remove.
For some reason KEF wanted to make these extra hard, so the wires are soldered in place, I might replace these with quick connect terminals, but maybe not.
Clip the wires, making sure to leave some of the insulation for when you reconnect the wires. You could also desolder the wires, and write down which wires go where.
This is what it should look like:
Here is your first driver:
But the catch is, the two woofers that need repair are inside the cabinet! How do you get to them?
Before you start make sure you have the right tools, you'll need quite a few for this project.
You need a 5/12" hollow-shafted socket driver, a #2 philips screwdriver, a pair of needle nose pliers, a normal pair of pliers, a of wire cutters, a wire stripper, a flat tool to pry, a hex driver or allen wrench, a soldering iron, solder, desolder wick.
Optional: plastic case to hold pieces
First, you must invert the speaker:
Remove the screws you find here, carefully pry the cover off, I used a flathead screwdriver.
You'll find fluff, remove this to reveal your first victim.
Voila!
Use your socket driver here to remove the four nuts:
You will also need to remove that center bolt. I didn't have a socket driver large enough for it so I carefully used needle nose pliers, this is a very long bolt so it takes some time.
It is not necessary but highly recommended to have some sort of container for all of the parts you remove.
For some reason KEF wanted to make these extra hard, so the wires are soldered in place, I might replace these with quick connect terminals, but maybe not.
Clip the wires, making sure to leave some of the insulation for when you reconnect the wires. You could also desolder the wires, and write down which wires go where.
This is what it should look like:
Here is your first driver:
Now stand the speaker upright and take a look at the crossover plate.
This is held in with a few hex head screws. You'll need an allen wrench for these, or a hex-driver.
You'll be presented by a bunch of wires, and a hole with fluff in it, remove the fluff to reveal the second driver. Remove the quick connect wires, marking their placement on the board, and clip or desolder the two wires that are not quick connects (WHY???)
And here you are:
Use your socket driver to remove the nuts. My driver was too tall and ran into the screw in the front left corner (looking in) so I had to remove one of the nuts with pliers.
Next you will need to remove the center bolt on the magnet. This will not work unless you reach through the port and grab the aluminum piece connecting the two drivers. I used pliers here.
There will be two wires paralleled off of the top driver's terminals that will need to be desoldered or snipped, I cut them.
Here is your bottom woofer!
I already had one of the other woofers refoamed
This is held in with a few hex head screws. You'll need an allen wrench for these, or a hex-driver.
You'll be presented by a bunch of wires, and a hole with fluff in it, remove the fluff to reveal the second driver. Remove the quick connect wires, marking their placement on the board, and clip or desolder the two wires that are not quick connects (WHY???)
And here you are:
Use your socket driver to remove the nuts. My driver was too tall and ran into the screw in the front left corner (looking in) so I had to remove one of the nuts with pliers.
Next you will need to remove the center bolt on the magnet. This will not work unless you reach through the port and grab the aluminum piece connecting the two drivers. I used pliers here.
There will be two wires paralleled off of the top driver's terminals that will need to be desoldered or snipped, I cut them.
Here is your bottom woofer!
I already had one of the other woofers refoamed
The rotten surrounds were original and it shouldn't be tricky to get replacements, only if you are cheap is it tricky (I am cheap) but you can find them and the donuts easily.
In this case two of the woofers had to be reconed entirely because the PO had played them too long with no surround and the coils had been destroyed.
In this case two of the woofers had to be reconed entirely because the PO had played them too long with no surround and the coils had been destroyed.
You back out the nuts and washers on the three threaded rods extending from the aluminum pot enclosing the uni-q driver. Then push on the ends of the threaded rods, which are attached to the frame of the mid range in an unusual way. The driver will resist being dislodged because there is foam damping and other friction resisting you. Do not pry from the front. When it's out you'll say "really???" and then move on to the tweeter, which is bolted from the back. It will also resist being dislodged, this time because of magnetic attraction to the pole piece. I went to the hardware store and got a threaded shaft the same diameter and pitch as the machine screw retaining the tweeter. This helps with alignment especially when reassembling. It's daunting on the first one, as usual.
Note that the wires on the new tweeter are heavier gauge and must be glued to the magnet structure of the tweeter or they will rub the voice coil former of the mid driver. I used Gorilla CA glue, which is the first "super" glue I've had success on metal with. I also used it to repair one of the captured nuts in the aluminum rod between the bass drivers which spun when I tightened it. Don't over torque anything on these speakers.
Note that the wires on the new tweeter are heavier gauge and must be glued to the magnet structure of the tweeter or they will rub the voice coil former of the mid driver. I used Gorilla CA glue, which is the first "super" glue I've had success on metal with. I also used it to repair one of the captured nuts in the aluminum rod between the bass drivers which spun when I tightened it. Don't over torque anything on these speakers.
Hello Sirbyrd, You seems to have good experience on KEF and help solve my problem.
I came across KEF Drive units: 4 x B200 bass unit (SP1188), 2 x B110 midrange unit (SP1190), 2x T33 tweeter (SP1191) and I picked them up. Now when trying to search was unable trace the speaker system I should built around. They are Woffers & midrage at 8ohms while tweeters are 4 ohms, there is no crossover so it worsen the search further. I know I have to put donut like cap on woofer which can be done. When searching for model number of driver unit it appear to be Kef 104/2 without one pair of midrange. Can you or anyone guide me on what should I do with these drivers and make them in to nice sounding speaker system. I'm reasonably OK at electronics and can build speaker if someone can help me, I am Indian based at Mumbai and have access to good quality electronics spares.
Thank you for reading.
Sachin
I came across KEF Drive units: 4 x B200 bass unit (SP1188), 2 x B110 midrange unit (SP1190), 2x T33 tweeter (SP1191) and I picked them up. Now when trying to search was unable trace the speaker system I should built around. They are Woffers & midrage at 8ohms while tweeters are 4 ohms, there is no crossover so it worsen the search further. I know I have to put donut like cap on woofer which can be done. When searching for model number of driver unit it appear to be Kef 104/2 without one pair of midrange. Can you or anyone guide me on what should I do with these drivers and make them in to nice sounding speaker system. I'm reasonably OK at electronics and can build speaker if someone can help me, I am Indian based at Mumbai and have access to good quality electronics spares.
Thank you for reading.
Sachin
I don't have enough experience with KEF other than situational with this model, so I must pass the buck to someone else.
Thanks for your advise, I will try for OEM crossover and balance mid range but if I don't then can I built them like 105.4 or 105 in one box??? I think I may get Philips crossover for 8 ohms...but please advise if this arrangement would serve purpose?
Thanks again,
Sachin
Hi SirByrd
You say "In this case two of the woofers had to be reconed entirely because the PO had played them too long with no surround and the coils had been destroyed.".
I take it than when you say "reconed entirely" youe man new voicecoil. ?
May I ask where you got that from (I have one brokken B160-woofer).
BR
Thomas
You say "In this case two of the woofers had to be reconed entirely because the PO had played them too long with no surround and the coils had been destroyed.".
I take it than when you say "reconed entirely" youe man new voicecoil. ?
May I ask where you got that from (I have one brokken B160-woofer).
BR
Thomas
I don't remember exactly where I had it done, but most any competent reconer should be able to do this model. Usually it's just the lower driver in each one that would be damaged from playing without the surround, since gravity will generally hang the upper cone in the center position.
Luckily in this case you won't see the bass driver so it's less of a visual issue to recone just the one that is damaged.
I don't recommend a full recone unless the voice coil is truly damaged, even if the voice coil gap is full of old foam from the donuts you can clean it out with iso alcohol.
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