I have a pair of much loved KEF 104ab speakers which have been in regular use for many years. Sadly, one of the B200 drivers has been damaged recently due to a fault in my amplifier (which has now been fixed).
These speakers use B200 drivers type SP1039, and I am having difficulty in obtaining replacement units. However, I can get a pair of B200 SP1054 units. The question is: can the SP1054 units be used in place of the SP1039 units in this speaker?
I have downloaded the spec sheets for both drivers and notice that there are subtle differences in their electrical and mechanical characteristics. In particular, the inductance of the SP1054 is greater than that of the SP1039. The impedance characterisitics of the drivers are therefore likely to be different, meaning that the SP1054 may not be well matched to the 104ab crossover circuit leading to a degradation of performance.
Does anyone have any views or experiences in this matter?
These speakers use B200 drivers type SP1039, and I am having difficulty in obtaining replacement units. However, I can get a pair of B200 SP1054 units. The question is: can the SP1054 units be used in place of the SP1039 units in this speaker?
I have downloaded the spec sheets for both drivers and notice that there are subtle differences in their electrical and mechanical characteristics. In particular, the inductance of the SP1054 is greater than that of the SP1039. The impedance characterisitics of the drivers are therefore likely to be different, meaning that the SP1054 may not be well matched to the 104ab crossover circuit leading to a degradation of performance.
Does anyone have any views or experiences in this matter?
B 200 Kef
Do you not have anyone in the UK who can repir the drivers and return them to original spec's?/
Iwould have thought that would be the best cheapest solution.
i like the B200 driver although I am not sure which one I have sitting in my garage at the moment ( unsuitable for your purposes sorry, but it has been reconed Kevlar as a Mid-base )
I wish you luck,
Regards ted
Do you not have anyone in the UK who can repir the drivers and return them to original spec's?/
Iwould have thought that would be the best cheapest solution.
i like the B200 driver although I am not sure which one I have sitting in my garage at the moment ( unsuitable for your purposes sorry, but it has been reconed Kevlar as a Mid-base )
I wish you luck,
Regards ted
Hi pshead. There is a v.good site in the UK that will be most useful. Without getting my old files out, as I understand it from memory, the two drivers are quite different. The B200 from the 104 or 104ab had a big magnet and a v.short voice coil compared with the one used in the infinite baffle systems. I'll try and find the site. Back in a minute.
Right, back again. Put "hifiloudspeakers.info" into google and you'll get the site with a couple of useful threads with all sorts of helpful people. Its entirely about KEF speakers and drive units. Hope its helpful.
Right, back again. Put "hifiloudspeakers.info" into google and you'll get the site with a couple of useful threads with all sorts of helpful people. Its entirely about KEF speakers and drive units. Hope its helpful.
Hi
If you want to have the speaker repaired wilmslow audio will do that for you.
If you want to keep the same speaker I think that might be the only way as I think you may wait a while for that particular model of B200 to appear for sale. The usual ones you find for sale are the earlier models with the smaller magnet.
Having said all that I have tried replacing the later B200 with one of the earlier ones and it does work and is hard to detect a difference by listening. However I have found that the best replacement for the later B200 is the Wharfedale 5" unit that is currently being sold in lots of 4 or more on e bay for only a few pounds ( I have found this a good speaker ). It gives a slightly changed mid balance but offers more detail than the B200. You may need to add a resistor - 1 to 3 ohm 10 watt - in line with the tweeter to reduce the treble slightly.
Don
If you want to have the speaker repaired wilmslow audio will do that for you.
If you want to keep the same speaker I think that might be the only way as I think you may wait a while for that particular model of B200 to appear for sale. The usual ones you find for sale are the earlier models with the smaller magnet.
Having said all that I have tried replacing the later B200 with one of the earlier ones and it does work and is hard to detect a difference by listening. However I have found that the best replacement for the later B200 is the Wharfedale 5" unit that is currently being sold in lots of 4 or more on e bay for only a few pounds ( I have found this a good speaker ). It gives a slightly changed mid balance but offers more detail than the B200. You may need to add a resistor - 1 to 3 ohm 10 watt - in line with the tweeter to reduce the treble slightly.
Don
Hi All,
Thanks for the comments and suggestions. I am considering the idea of having the unit re-coned, but suspect that it may be expensive. Also, it would probably be necessary to have both units re-coned to ensure matching, even though one of the pair is undamaged.
I guess I will just have to look out for a pair of SP1039 drivers!
The SP1054 unit did look attractive as it is more sensitive than the SP1039 and also has a higher power rating.
Regards,
pshead
Thanks for the comments and suggestions. I am considering the idea of having the unit re-coned, but suspect that it may be expensive. Also, it would probably be necessary to have both units re-coned to ensure matching, even though one of the pair is undamaged.
I guess I will just have to look out for a pair of SP1039 drivers!
The SP1054 unit did look attractive as it is more sensitive than the SP1039 and also has a higher power rating.
Regards,
pshead
It's all starting to come back.......there were at least three B200's There was a small mag' version for the 20 litre infinite baffles(Chorales) Then two versions with larger magnets. One was in the Cadenza and the other was for the 104/104ab. As I understand it although both the 104 and Cadenza were ABR types the two units are not the same. But I think a B200 out of a 104 would be compatible with the 104ab as the latter differed only in the cross over. The "ab" refering to the Acoustic Butterworth nature of the tweeter's output after the cross over mod.
AMV8 I wonder if your reference to five inch Warfedales are really replacements for the B110 and not B200 which is a bit over 8" in diameter?
AMV8 I wonder if your reference to five inch Warfedales are really replacements for the B110 and not B200 which is a bit over 8" in diameter?
Jonathan Bright said:
5 as of the late 70s and more since -- i've seen at least 1 version with the triangular bezel that i don't have listed here
http://www.t-linespeakers.org/drivers/b200.html
dave
yea dave knows his b200's
One of the versions with triangular mounting was the b200g
-sp1075.
It was offered in a diy-kit called cs-3 , which was a close equivalent of the 103.2 if my memory is correct.
I still have the datasheet, parameters are quite different from earlier versions using 4-point mounting.
dcr was 4.7r, Q was 0,37 despite it's fairly small magnet.
Effective cone-area was increased to 246 cm2
Another triangle-mounted version was used in the 303.3, this version had an inverted surround.
best regards,
Klaas
-sp1075.
It was offered in a diy-kit called cs-3 , which was a close equivalent of the 103.2 if my memory is correct.
I still have the datasheet, parameters are quite different from earlier versions using 4-point mounting.
dcr was 4.7r, Q was 0,37 despite it's fairly small magnet.
Effective cone-area was increased to 246 cm2
Another triangle-mounted version was used in the 303.3, this version had an inverted surround.
best regards,
Klaas
further KEF B200 question....
I know its quite a time since the last post on this thread, and some of you contributors may have already had the Last Post played over your graves by now, BUT if any of you are still alive and kicking, and can remember what the various B200 models were, and are prepared to help you, PLEASE read on!!!
In the early 80s I bought a pair of CELEF (now ProAc) RT1s, serial numbers 0011 and 0012 from Audio Centre in Sheffield, UK. They were the absolute top KEF model...with a Decca Ribbon horn tweeter in the middle, using the same compartment as an ATC 234 bass unit, and on top was a Kef B200 in an open backed compartment about a foot cube, but, as I say, open backed. They were SUPERB, but as I progressed, I tweaked the crossovers for the better, and then even got them going active.
However....
At one point late in their life these were dismantled. I still have the ATCs and the Deccas and the Crossover...
Does anyone know which B200s were in these, OR which B200s would be best OR which B200s ARE the best, OR what would be a better midrange?
Many, many thanks, guys!
I know its quite a time since the last post on this thread, and some of you contributors may have already had the Last Post played over your graves by now, BUT if any of you are still alive and kicking, and can remember what the various B200 models were, and are prepared to help you, PLEASE read on!!!
In the early 80s I bought a pair of CELEF (now ProAc) RT1s, serial numbers 0011 and 0012 from Audio Centre in Sheffield, UK. They were the absolute top KEF model...with a Decca Ribbon horn tweeter in the middle, using the same compartment as an ATC 234 bass unit, and on top was a Kef B200 in an open backed compartment about a foot cube, but, as I say, open backed. They were SUPERB, but as I progressed, I tweaked the crossovers for the better, and then even got them going active.
However....
At one point late in their life these were dismantled. I still have the ATCs and the Deccas and the Crossover...
Does anyone know which B200s were in these, OR which B200s would be best OR which B200s ARE the best, OR what would be a better midrange?
Many, many thanks, guys!
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