KEF 104aB B200 SP1039

[Benjib]

I just acquired a set of KEF 104aB that I am reconditioning. New caps from falcon acoustics are in the mail. Got some fine sandpaper and boiled linseed oil for the tired cabinets. My only remaining challenge are the SP1039 drivers. The surrounds have become a little flat. I know this is common with these units and I’ve seen lots that are far worse than mine. These have lost maybe 35% of their roundness. Still seem to sound great - but I’m a bit of a perfectionist. These drivers seem impossible to find on the used market. I’ve replaced deteriorated foam surrounds on other speakers but not rubber on bextrene like these. Is it doable? I can’t even find the right rubber surrounds online to even consider. Maybe I should call some reputable speaker shops in my city (Toronto)? What’s my best course of action? Definitely keeping my eyes on listings on the usual sites. Thoughts???

 

[crdm6]

I would Email Falcon and ask them if the flatter surrounds are a problem and if so what is their suggestion. Malcom Jones is there, they should know. I would guess that if you ask, Wilmslow would just suggest replacing them.

I did ask Falcon about a modern equivalent for the "big magnet" B200 for a new build and they said if that "Bextrene" sound is what I want, I should buy used ones on Ebay. Yeah, good luck with that. If any come up on Ebay 99.9% of them are in England, they aren't cheap and shipping is very expensive.
This of course is not an answer to the question of if our current B200s have a problem but it is interesting.

Shoot them an Email and let us know what they say.

 

[Benjib]

I would Email Falcon and ask them if the flatter surrounds are a problem and if so what is their suggestion. Malcom Jones is there, they should know. I would guess that if you ask, Wilmslow would just suggest replacing them.

I did ask Falcon about a modern equivalent for the "big magnet" B200 for a new build and they said if that "Bextrene" sound is what I want, I should buy used ones on Ebay. Yeah, good luck with that. If any come up on Ebay 99.9% of them are in England, they aren't cheap and shipping is very expensive.
This of course is not an answer to the question of if our current B200s have a problem but it is interesting.

Shoot them an Email and let us know what they say.

Falcon hasn’t replied to any of my emails. I inquired a few times about the caps I was ordering but all went unanswered. They did accept my order then messaged to tell me they couldn’t meet the order for 2 of the 5 types I ordered and that they could substitute with a lesser grade. They then neglected to adjust the cost of my order. It was only a small amount, but still. So as much as I’ve heard great things about their service, my experience hasn’t been good at all. This is unfortunate as they are indeed the most knowledgeable. So I turn to the awesome community here for help.

 

[SaSi]

The short answer to this is that this flattness, if it's not too much, has negligible effect to the sound. At most, it may slightly influence max excursion, only if you push them too hard.

 

[Benjib]

The short answer to this is that this flattness, if it's not too much, has negligible effect to the sound. At most, it may slightly influence max excursion, only if you push them too hard.

Thank you for your thoughts. I don’t think they’ll ever see even 50% of their capacity. I sure would like to have the beefy look of the full roll though. Ever hear of anyone doing a surround replacement? I’ve searched the forums and can’t find much reference to doing this - good or bad. For such a common problem with a well liked driver, why isn’t anyone redoing the surrounds? All I can figure is that it isn’t possible for material reasons?

 

[crdm6]

As I said in your other thread, my Calindas also have kinda flat surrounds and sound great.

I have reached out to a friend in the biz who I'm pretty sure was a KEF dealer back in the day asking if he has any insight into the surround question. I'll report on what he says.

 

[Benjib]

As I said in your other thread, my Calindas also have kinda flat surrounds and sound great.

I have reached out to a friend in the biz who I'm pretty sure was a KEF dealer back in the day asking if he has any insight into the surround question. I'll report on what he says.

Great thanks. I’m really glad I decided to purchase these but I sure would like them to be 100%. I’d spend some money to get them looking as good as they sound. Without gills, the driver esthetics are that much more important. Would love to find a quality used pair of drivers or be able to replace these surrounds. Fingers crossed. And man oh man they continue to impress me! One of the best sounding speaker I’ve owned.

 

[crdm6]

I'll just say it.
KEF B200 the best all around woofer/midrange ever that was available individually.

Haven't heard back yet from the friend.

 

[crdm6]

Friend responded and said he wasn't a KEF dealer. Must have been a used set I remember seeing in the shop. It was 1987 so I give me a pass on the memory failure. Sorry.
Other people are having problems with Falcon. Uh oh.

 

[Benjib]

Friend responded and said he wasn't a KEF dealer. Must have been a used set I remember seeing in the shop. It was 1987 so I give me a pass on the memory failure. Sorry.
Other people are having problems with Falcon. Uh oh.

Thanks for trying. These speakers are so, so good. Everything sounds amazing. I agree, special driver(s) indeed.

I’m not the only one eh? Didn’t realize it was a trend. Hopefully it’s just a temporary situation.

 

[sax6]

Kef B200 SP 1054 are oftently available on the '' selling site '' sadly, for much money.

Edited...

Oh, it's a 1039 inside the 104 ?

 

[Lou G]

I have KEF Calinda speakers that I purchased new in 1979. They are still going strong in my third (office) system. I just looked at the rubber surrounds on the B200 and they look the same as the day I purchased them.

 

[absolve2525]

Well that's quite strange! I just recently ordered and received a pair of their Falcon B110 midranges with great service. I haven't tried their capacitors but was contemplating at some point.

Falcon hasn’t replied to any of my emails. I inquired a few times about the caps I was ordering but all went unanswered. They did accept my order then messaged to tell me they couldn’t meet the order for 2 of the 5 types I ordered and that they could substitute with a lesser grade. They then neglected to adjust the cost of my order. It was only a small amount, but still. So as much as I’ve heard great things about their service, my experience hasn’t been good at all. This is unfortunate as they are indeed the most knowledgeable. So I turn to the awesome community here for help.

 

[crdm6]

The web page has been saying the store is closed because of sickness since at least the 17th. It does say the web store is open so who knows?

I just looked at the rubber surrounds on the B200 and they look the same as the day I purchased them.

Perhaps you could measure them? Since you are the original owner you would know if they had been replaced/repaired at some point.

I was trying to take pictures of my B200s but it is tough to photograph black on black to show the curve.
I did notice (can't believe I didn't see this before) that the surrounds on my SP1054s are bigger than my SP1014s.
If you measure them from the inside edge (glued to the cone) to the outside edge (glued to the chassis), mine measured 1 and 3/8s.
My SP1014s measured 1 and 3/16s.

This might answer the question of do the "big magnet" models have a different surround.

If enough people could measure their B200s and report in, we might have an answer.

 

[Lou G]

As I mentioned before I purchased my Calindas new and the drivers are all original. I just measured the B200 surrounds from the inside edge to the outside edge and they measure 38 mm or about 1 and 1/2 inches.

 

[crdm6]

As I mentioned before I purchased my Calindas new and the drivers are all original. I just measured the B200 surrounds from the inside edge to the outside edge and they measure 38 mm or about 1 and 1/2 inches.

Thanks Lou G!

Just got an Email back from Jerry at Falcon. I asked about the rumor of new B200s and about the "big magnet" surrounds.


"To answer the rumour - possible later this year. Busy on other things right now.
Surrounds. Big magnet versions with rubber surrounds stable. Where PVC surround used, yes, they degrade shape over time due to aging/any plasticiser migration."


So...
1) They are reading and responding to Emails. Yay!
2) The surrounds aren't flattening, they were always flatter.
3) More measurements of surrounds will still be good for piece of mind.
4) If anything bad happens to our B200s, we might be able to replace them.
5) It won't be cheap.

I just was looking at the different B200 spec sheets.
The linear excursion Xd is similar on all of them but the SP1039 and SP1054 have much higher damage limit limits. 12mm vs 20mm. The SP1022 had the large magnet but the 12mm limit.
We need somebody with a KEF Cadenza which uses the SP1022 to measure their surround.

 

[Benjib]

Thanks Lou G!

Just got an Email back from Jerry at Falcon. I asked about the rumor of new B200s and about the "big magnet" surrounds.


"To answer the rumour - possible later this year. Busy on other things right now.
Surrounds. Big magnet versions with rubber surrounds stable. Where PVC surround used, yes, they degrade shape over time due to aging/any plasticiser migration."


So...
1) They are reading and responding to Emails. Yay!
2) The surrounds aren't flattening, they were always flatter.
3) More measurements of surrounds will still be good for piece of mind.
4) If anything bad happens to our B200s, we might be able to replace them.
5) It won't be cheap.

I just was looking at the different B200 spec sheets.
The linear excursion Xd is similar on all of them but the SP1039 and SP1054 have much higher damage limit limits. 12mm vs 20mm. The SP1022 had the large magnet but the 12mm limit.
We need somebody with a KEF Cadenza which uses the SP1022 to measure their surround.

I’m liking this conversation very much. I’m not understanding, though, how the big magnet 1039 with the greater excursion could have the flatter surround as you suggest is #2. The greater excursion should mean greater roll on the surround. Note, too, that no early image of the 1039 shows anything but a very perky, fat (dare I say sexy) surround. I do believe the problem of the deflating surround is unique to the 1039 version of the B200 - this must have been where pvc was used instead of rubber. My last speakers had the B200 sp1014 (Monitor Audio MA5) and it was visibly different, I had them side by side. It is indeed excellent FA is responding and providing info. Good news too they might finally build a replacement B200! Looking at the price of the B110 isn’t encouraging though! Haha

 

[crdm6]

I joined the SpeakerTalk forum on hifiloudspeakers.info which is all KEF all the time. Why didn't I do this before? They of course have answers. The Xmax damage spec depends on the spider used not the surround. It was pointed out to me that in models with a ABR the woofer cone has less excursion than a sealed box. Doh! The surround on the 1039 is PVC which can have issues. The 1054 and 1014 are made of rubber and are good to go.

I am paraphrasing their answers. You can read the whole thing without joining which is kind of complicated.

I still think the surrounds are in fact bigger on the 1039 and 1054 but it probably has nothing to do with people having problems with their 1039s.

SpeakerTalk forum is KEF heaven.

 

[Benjib]

I joined the SpeakerTalk forum on hifiloudspeakers.info which is all KEF all the time. Why didn't I do this before? They of course have answers. The Xmax damage spec depends on the spider used not the surround. It was pointed out to me that in models with a ABR the woofer cone has less excursion than a sealed box. Doh! The surround on the 1039 is PVC which can have issues. The 1054 and 1014 are made of rubber and are good to go.

I am paraphrasing their answers. You can read the whole thing without joining which is kind of complicated.

I still think the surrounds are in fact bigger on the 1039 and 1054 but it probably has nothing to do with people having problems with their 1039s.

SpeakerTalk forum is KEF heaven.

Wow, thanks!! In all my obsessive research I somehow missed that forum, although I did happen across some of the content second hand. I was up way past my bedtime last night reading KEF heaven indeed!

It was surprising to see just how flat some of these 1039 surrounds have become and folks are still listening to them; I feel better about mine - but I’ll still likely pay some big money when I can find a a pair in excellent shape, although I don’t think I’ll pay mega bucks for the new edition if FA does bring such a thing to market.

Gotta pivot my focus onto my crossovers now, the caps from FA should arrive any day. I gotta admit being nervous about updating them. These things sound so so sweet as they are and I’ve never done a recapping job. Hope I don’t F it up!

 

[crdm6]

If the surrounds on the 1039 are degrading with time the chance of you finding an "as new" set is pretty low. Perhaps someone somewhere took some brand new ones and sealed them in a container with inert gas. Yeah right! How much would they want for them? Probably more than Falcon will ask.

The only issue with recapping (assuming you already know how to solder) is on some of the PCBs the tracks are huge and suck up the heat. You will need some real heat to do this not a wimpy 20 watt. If necessary you can put a metal clip on the cap lead as a heat sink.