I've got a pair of KEF 103/4 on a garage sale with bass drivers shot.
Surrounds are all rotten and have to be replaced, for sure. I have tested
all 4 drivers, and only one voice coil is OK, others are open, pressumably shot.
I would like to get any data on these drivers. KEF model B160 Sp1302, 8 Ohm.
Those are fitted two per cabinet and connected with a steel rod.
I guess I should plan for worse case scenario, just in case and would need
complete recone with new coil and spider as well as surrounds.
What about foam dustcap? it's not traditional style, it's more like donate shape
made of the same foam material as surround.
What are my options? I would like to do this myself, but parts might be a problem.
where can I get those? I have never fix drivers before, just build some speakers and crossovers.
Refoaming looks easy but complete recone is unknown to me.
Any recommendation from you guys?
What are the opinions about importance of the donate-dustcap where the rod is passing through?
Thanks in advance.
Igor
Surrounds are all rotten and have to be replaced, for sure. I have tested
all 4 drivers, and only one voice coil is OK, others are open, pressumably shot.
I would like to get any data on these drivers. KEF model B160 Sp1302, 8 Ohm.
Those are fitted two per cabinet and connected with a steel rod.
I guess I should plan for worse case scenario, just in case and would need
complete recone with new coil and spider as well as surrounds.
What about foam dustcap? it's not traditional style, it's more like donate shape
made of the same foam material as surround.
What are my options? I would like to do this myself, but parts might be a problem.
where can I get those? I have never fix drivers before, just build some speakers and crossovers.
Refoaming looks easy but complete recone is unknown to me.
Any recommendation from you guys?
What are the opinions about importance of the donate-dustcap where the rod is passing through?
Thanks in advance.
Igor
Hi Igor, I would suggest that you contact KEF for replacement woofers. If the coils as well as the foam surrounds are gone then they are your only hope for replacements.
The centre "doughnut" dustcap is actually a rolling seal because of the need to connect the two drivers with the force cancelling rod. You will not find aftermarket replacements for these.
Good luck
Andrew
The centre "doughnut" dustcap is actually a rolling seal because of the need to connect the two drivers with the force cancelling rod. You will not find aftermarket replacements for these.
Good luck
Andrew
Andrew,
Well, KEF doesn't have a replacements for some time now.
I guess complete recone is in order.
Voice Coils on all 4 drivers look OK and Cone is moveng, albeit with some scratching noise.
Does that mean VC former is shot and not the coil?
Also, the only working driver sounds bad, but with no surrounds and rolling seal (as you said) doesn't mean much, I guess.
What is that "rolling seal"? Is it necessary for the "sound"?
Does anyone know for sure?
Thanks
Igor
Well, KEF doesn't have a replacements for some time now.
I guess complete recone is in order.
Voice Coils on all 4 drivers look OK and Cone is moveng, albeit with some scratching noise.
Does that mean VC former is shot and not the coil?
Also, the only working driver sounds bad, but with no surrounds and rolling seal (as you said) doesn't mean much, I guess.
What is that "rolling seal"? Is it necessary for the "sound"?
Does anyone know for sure?
Thanks
Igor
Igor, if the voice coils are in-tact, ie measuring somewhere around 4-6 ohms resistance, then they should be OK. The scratching sound is caused by the coil rubbing against the top plate because of the rotted sourround no longer keeping the coil centered in the gap.
even if you find a repair kit for the surrounds you are still left with the problem of the rolling seal. I do not think you will find a replacement for this.
The only other solution is to forget about the force cancelling rod and just use a regualr dustcap. The force cancelling rod is used to reduce box vibration and clean up the sound. Without it the speaker will still work, though there will be more box colouration to the sound. Make sure if you do this that you adequately fasten the drivers into the box.
The driver parameters are critical to the performance. Not only do they determine the box tuning, but also the impedance seen by the xover. The xover is very complex, and the driver impedance is heavily conjugated in order for the xover to work correctly. If you change the driver for a substitute you will find that the xover response and impedance may go haywire!
All the best
Andrew
even if you find a repair kit for the surrounds you are still left with the problem of the rolling seal. I do not think you will find a replacement for this.
The only other solution is to forget about the force cancelling rod and just use a regualr dustcap. The force cancelling rod is used to reduce box vibration and clean up the sound. Without it the speaker will still work, though there will be more box colouration to the sound. Make sure if you do this that you adequately fasten the drivers into the box.
The driver parameters are critical to the performance. Not only do they determine the box tuning, but also the impedance seen by the xover. The xover is very complex, and the driver impedance is heavily conjugated in order for the xover to work correctly. If you change the driver for a substitute you will find that the xover response and impedance may go haywire!
All the best
Andrew
Allenr,
Very easy. Take out the 8 screws holding the terminal plate at the back of the cabinet. The plate comes away with a little persuasion. Make a note of the wire colours and their connection terminals.
Remove the souns wadding, the top speaker is now accessible, remove the centre screw in the magnet, which holds the force cancelling rod in position.
Turn the cabinet over, remove the spikes and all the Posidrive wood screws, and take out the bottom wood piece. The bottom speaker is upside down, and the connections are soldered. You can either feed the wire connections through from the top, or just cut them close to the speaker and resolder them later when refitting. Again, remove the force cancelling rod screw.
I repaired myself, the inner, smaller seals were rotted too. I got the surrounds in UK, about 30 pounds, 60 dollars. Its not too difficult, if you are patient and precise in repositioning the speaker cone in the centre. It must'nt scrape in the magnet centre!
I can let you know the foam supplier I used, if you need.
Rich
Very easy. Take out the 8 screws holding the terminal plate at the back of the cabinet. The plate comes away with a little persuasion. Make a note of the wire colours and their connection terminals.
Remove the souns wadding, the top speaker is now accessible, remove the centre screw in the magnet, which holds the force cancelling rod in position.
Turn the cabinet over, remove the spikes and all the Posidrive wood screws, and take out the bottom wood piece. The bottom speaker is upside down, and the connections are soldered. You can either feed the wire connections through from the top, or just cut them close to the speaker and resolder them later when refitting. Again, remove the force cancelling rod screw.
I repaired myself, the inner, smaller seals were rotted too. I got the surrounds in UK, about 30 pounds, 60 dollars. Its not too difficult, if you are patient and precise in repositioning the speaker cone in the centre. It must'nt scrape in the magnet centre!
I can let you know the foam supplier I used, if you need.
Rich
Thanks a lot pal!
I tried to unscrew the back panel before but did not dare to remove it since I lack the "pursuasion"
Anyway, I think I might need to send the whole cabinets to a local repairer since I have no experience in soldering...
How are these speakers sound after you restored them? Worth the trouble at all?
I tried to unscrew the back panel before but did not dare to remove it since I lack the "pursuasion"
Anyway, I think I might need to send the whole cabinets to a local repairer since I have no experience in soldering...
How are these speakers sound after you restored them? Worth the trouble at all?
You just have to prise the plate gently with a flat screw driver to break the seal. Its not difficult. Then wiggle the plate out, it has the cross over network circuit board fitted to it.
The speakers are lacking in base imo. The mids and highs are excellent.
Perhaps with a separate sub woofer, they would be very good.
I got all the foams, outer and inners from:
speaker-repairs.co.uk
The speakers are lacking in base imo. The mids and highs are excellent.
Perhaps with a separate sub woofer, they would be very good.
I got all the foams, outer and inners from:
speaker-repairs.co.uk
Kef 103/4 woofers
Hi,
I have the same problem but my woofers. I have looked for a repair kit (they are some for 8'' woofers though) in USA and could'nt find one. I contacted Kef and they want me to buy new speakers...
My solution... a good subwoofer. I connect the amplifier outputs to the sub and the sub speaker level terminals to the LF input of my Kef 103/4 speakers. Of course, for the HF section I use another line directly from the amplifier to avoid sub crossover for high frequencies.
The sound is as good as it was if not better. And I have the full control over low frequencies.
JiPi
Hi,
I have the same problem but my woofers. I have looked for a repair kit (they are some for 8'' woofers though) in USA and could'nt find one. I contacted Kef and they want me to buy new speakers...
My solution... a good subwoofer. I connect the amplifier outputs to the sub and the sub speaker level terminals to the LF input of my Kef 103/4 speakers. Of course, for the HF section I use another line directly from the amplifier to avoid sub crossover for high frequencies.
The sound is as good as it was if not better. And I have the full control over low frequencies.
JiPi
Kef 103/4 woofers recconed
HI RichG4PCE,
You're lucky! Were did you find your repair kit for 6'' woofers? Do you think I could get it here in Canada? How much did you pay for? I have only one cone in really bad shape. The others are either in perfect condition or only the doughnout has to be replaced.
Thank you!
JiPi
HI RichG4PCE,
You're lucky! Were did you find your repair kit for 6'' woofers? Do you think I could get it here in Canada? How much did you pay for? I have only one cone in really bad shape. The others are either in perfect condition or only the doughnout has to be replaced.
Thank you!
JiPi
I have a bit of a worst-case scenario with my B160 bass drivers - all 4 of them. I won a pair of KEF 103.4's at auction and the tweeter and mid are fine however I knew the surrounds of the bass drivers were likely to be shot. I also knew if the last owner had driven them with perished surrounds the bass drivers could be shot.
Worst case scenario in all 4 of the drivers extracted so far - totally open circuit in the drivers and the cone is rubbing stiffly in the VC gap. Two of them had a literal meltdown they were driven so hard - the plastic in the middle of 2 of them completely melted.
I managed to knock the price down for this as the owner had them in a cafe and hadnt tested them for years and I really need another project (lols).
As I got them so cheap - Im happy to tolerate a "close enough" approach. I already have a pair of 104.2's that are close to 90% good, so if these come close to 100% thats fine.
It doesnt seem like I can get a recone kit for these drivers. Sending them to and from KEF (from NZ) isnt an option due to weight.
Anyone know of a potential DIY fairly generic recone kit that could fit these drivers? It seems a shame to replace the drivers entirely as my reluctant 2nd option will be this.
cheers
Worst case scenario in all 4 of the drivers extracted so far - totally open circuit in the drivers and the cone is rubbing stiffly in the VC gap. Two of them had a literal meltdown they were driven so hard - the plastic in the middle of 2 of them completely melted.
I managed to knock the price down for this as the owner had them in a cafe and hadnt tested them for years and I really need another project (lols).
As I got them so cheap - Im happy to tolerate a "close enough" approach. I already have a pair of 104.2's that are close to 90% good, so if these come close to 100% thats fine.
It doesnt seem like I can get a recone kit for these drivers. Sending them to and from KEF (from NZ) isnt an option due to weight.
Anyone know of a potential DIY fairly generic recone kit that could fit these drivers? It seems a shame to replace the drivers entirely as my reluctant 2nd option will be this.
cheers
Are you sure the tweeters are still good? I've done one pair of these and had to replace the tweeters with replacements no longer available from KEF. I would expect the ferrofluid to be cooked if the woofers are as roasted as you describe. Even if you delete the steel rod you still have force cancellation from the bass drivers facing each other, as far as that bit goes.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.