Yesterday I bought a set of KEF 103.2 speakers. Oldies but decent speakers.
When I got home I connected them and everything sounded quite nice. Then I put on a vinyl record by "Nightmares on wax", a quite bass heavy record.
This was all on moderate volume.
After a minute or so the bass became noisy, as like the subbass was made with a noise component.
So I read about the crossfilters needing a recap, so before I ordered a recap set, I did some tests.
Long story short, when I finally connected the speaker out directly to the woofer, i heard the same kind of distortion......so there must be something wrong with the woofers. They don't sound blown to me, but they don't sound right either.
Did I just buy a pair of duds or is there an easy fix for the woofers, so I can order the recap set, instead of throwing this lovely set in the garbage,
When I got home I connected them and everything sounded quite nice. Then I put on a vinyl record by "Nightmares on wax", a quite bass heavy record.
This was all on moderate volume.
After a minute or so the bass became noisy, as like the subbass was made with a noise component.
So I read about the crossfilters needing a recap, so before I ordered a recap set, I did some tests.
Long story short, when I finally connected the speaker out directly to the woofer, i heard the same kind of distortion......so there must be something wrong with the woofers. They don't sound blown to me, but they don't sound right either.
Did I just buy a pair of duds or is there an easy fix for the woofers, so I can order the recap set, instead of throwing this lovely set in the garbage,
After more reading, I think it is so called woofer sag. When I press the woofer softly, the buzzing stops, only to return seconds after I lift my finger.
I read rotating the woofers might help, but after doing that, the problem is still there.
I read rotating the woofers might help, but after doing that, the problem is still there.
It is good to read you first did some fault finding before rushing off for a "recap set". That would have been stupid.
I would have guessed woofer sag as well. Since you turned the drivers upside down can preclude that.
Unlikely, check the connection wires to the coil. I don't know the correct name, but those are the flexible wires from the terminals, usually through the membrane to the coil.
If that is fine, it sounds like a particle in the air gap. I have no idea how to get that out. And then it is a difference whether it is on the inside of the outside of the coil.
I would have guessed woofer sag as well. Since you turned the drivers upside down can preclude that.
Unlikely, check the connection wires to the coil. I don't know the correct name, but those are the flexible wires from the terminals, usually through the membrane to the coil.
If that is fine, it sounds like a particle in the air gap. I have no idea how to get that out. And then it is a difference whether it is on the inside of the outside of the coil.
This loudspeaker hails from the early 1980s. Old glue can become brittle with age and shed particles that end up getting stuck in the voice coil gap.
The flexible wires are called tinsel leads by the way. I've seen instances where these come into contact with each other and cause a stuttering distortion. The solution is to bend them apart again.
The three point mounting woofer is likely a B200G SP1075. Please remove a woofer to see if there is a label that confirms this.
I read that the triangle shaped woofer needed to be "routinely" rotated in order to prevent sagging of the spider resulting in the voice coil rubbing.
Consequently, it may be too late to rescue your woofers - and replacement used B200 SP1075 drivers may well show identical symptoms.
Your only hope may be in sourcing a compatible modern equivalent. However, that may prove problematical as those KEF units are pretty unique.
Consequently, it may be too late to rescue your woofers - and replacement used B200 SP1075 drivers may well show identical symptoms.
Your only hope may be in sourcing a compatible modern equivalent. However, that may prove problematical as those KEF units are pretty unique.
Did you try both other orientations, especially the one nearest opposite the area where pressure makes it worse (or nearest where pressure makes it better)? Sometimes it takes time to correct the sag, or more effort. I've had success doing what SubSonics suggests using a hairdryer with focus on the spider, if this is the problem area. Some dryers also have a cooling function which is handy. Use heat carefully so as not to make things worse.
If it isn't suspension sag there might be a failed glue joint somewhere, such as surround to cone or spider to cone. Worth checking these first.
From the symptoms this can be fixed, once the fault is identified.
Thanks for all the help.
So, yesterday I got really active on these KEF's.
I took out the crossover, to check on leaky caps. I only found 2 corroded resistor. The rest looked fine.
So I decided to take out the relay, made a short there, shorted R1 to take the whole protection out.
Put it back in......problem was still there. So I decided to play some music on low volume and massage the woofer on the opposite site off the noisy rattle. Inactive the coil does seem to touch the magnet. After this massage I've been listening to speakers all day, playing records and cd's.
Every once in a while it is back, only on certain low tones. But I'm hopefull it will disappear totally.
I do love the sound of these speakers, but it feels like they were designed with particular music in mind. The don't sound that nice on high volumes with rock for instance. So I'm not sure if they are keepers and worth recapping.
So, yesterday I got really active on these KEF's.
I took out the crossover, to check on leaky caps. I only found 2 corroded resistor. The rest looked fine.
So I decided to take out the relay, made a short there, shorted R1 to take the whole protection out.
Put it back in......problem was still there. So I decided to play some music on low volume and massage the woofer on the opposite site off the noisy rattle. Inactive the coil does seem to touch the magnet. After this massage I've been listening to speakers all day, playing records and cd's.
Every once in a while it is back, only on certain low tones. But I'm hopefull it will disappear totally.
I do love the sound of these speakers, but it feels like they were designed with particular music in mind. The don't sound that nice on high volumes with rock for instance. So I'm not sure if they are keepers and worth recapping.
Update. The problem returned. So I took out the woofer, sprayed the spider with some water. Then I placed a folded towel on the opposite corner of the rub(you can feel/hear where the rubbing is), between the magnet and the membrane, so that the membrame was lifted almost to max.
Then I placed the woover upside down in the cabinet hole and let it sit for 12 hours.
This morning I reassembled the speaker and I'v been listening to music, while working from home, for 10 hours.
I listened jazz, classic, chansons, hiphop, punk, soul and metal. I really love these speaker, incredible. Glistering highs, beautiful mids and enough bass.
Thanks. New project will be replacing the RCA cables on my Technics 1700
Then I placed the woover upside down in the cabinet hole and let it sit for 12 hours.
This morning I reassembled the speaker and I'v been listening to music, while working from home, for 10 hours.
I listened jazz, classic, chansons, hiphop, punk, soul and metal. I really love these speaker, incredible. Glistering highs, beautiful mids and enough bass.
Thanks. New project will be replacing the RCA cables on my Technics 1700
So problem solved? Nice to know your creative solution.
In about five pairs of KEF speakers with the B200G I had one woofer whose coil touched the magnet (I assumed) and made a distorting sound. It still sits on the shelf. Maybe I should try your treatment.
But I had another interesting problem with a B200G: The coating on the back of the cone had run into the groove of the surround and built up some crusts. these touched the surrounds at certain frequencies and made a buzzing sound. at some point I carefully filed these crusts away and solved the problem, but it took me a long tie to find it.
Great speakers, I agree. After a decent recap I find them outright fantastic.
In about five pairs of KEF speakers with the B200G I had one woofer whose coil touched the magnet (I assumed) and made a distorting sound. It still sits on the shelf. Maybe I should try your treatment.
But I had another interesting problem with a B200G: The coating on the back of the cone had run into the groove of the surround and built up some crusts. these touched the surrounds at certain frequencies and made a buzzing sound. at some point I carefully filed these crusts away and solved the problem, but it took me a long tie to find it.
Great speakers, I agree. After a decent recap I find them outright fantastic.
JeanPS71, your 'fix' is good but the buzz will return eventually.
There's another 'fix' which I usually do but your method is probably as good as mine.
I would check out the price of replacement units from KEF itself.
There's another 'fix' which I usually do but your method is probably as good as mine.
I would check out the price of replacement units from KEF itself.
Probably a better chance of winning the lottery. These woofers were OOP by the mid 80's.
jeff
I've owned quite a few KEF speakers from this era and they all ended up buzzing as described. I "think" the enamel / glue on the voice coil breaks down. I also think they sound great.
Last edited:
I have a mint pair of these and haven't had that problem yet, but I will rotate those woofers asap.
Wow this a saddening concept. Are there any modern speakers that sound like these? I'v heard a lot of new KEF models and they just don;t do it for me.
I suspect not as these speakers are no doubt flawed by modern standards, but great to listen to. Been meaning to listen to the new KEF META's but haven't got to the shop yet. I currently use AE1's which are excellent but sound nothing like the KEF's.
I have had only one bad B200G in about ten or twelve, so I can't confirm @triplej 's finding. My first pair from 1984 still does daily duty at my daughter's place. She is a musician. I am using another pair in my study.
I am equally not sure if the speakers are "flawed by modern standards". They are very, very linear, and also an easy load on amps.
Original 103.2's need a recap though to sound as they are intended to, even if there are no obvious electrical faults. A known problem is that an electrolytic cap in the protection circuit on the crossover starts to leak and destroys the PCB trace related to the woofer. Easy to repair, though.
I am equally not sure if the speakers are "flawed by modern standards". They are very, very linear, and also an easy load on amps.
Original 103.2's need a recap though to sound as they are intended to, even if there are no obvious electrical faults. A known problem is that an electrolytic cap in the protection circuit on the crossover starts to leak and destroys the PCB trace related to the woofer. Easy to repair, though.