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Old 15th September 2011, 03:51 PM   #11
Boden is offline Boden  Netherlands
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Welcome to the wonderful world of KEF in de late seventies/early eighties. QC either absent or on sick leave.

I owned a number of B 139 's with Fs around 36 and 40 Hz (!) and rubbing VC's at any level over 2-3 Volts driving voltage. Cones were not flatly glued in place..

They worked reasonably well in my Chris Rogers' Practical Hifi ' PRO 9 TL, but in terms of build quality, power handling plus specs they were definitely not something to write home about.

Hope you have more luck with your samples.

Regards,

Eelco
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Old 15th September 2011, 03:55 PM   #12
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Quote:
Originally Posted by Boden View Post
Welcome to the wonderful world of KEF in de late seventies/early eighties. QC either absent or on sick leave.

I owned a number of B 139 's with Fs around 36 and 40 Hz (!) and rubbing VC's at any level over 2-3 Volts driving voltage. Cones were not flatly glued in place..

They worked reasonably well in my Chris Rogers' Practical Hifi ' PRO 9 TL, but in terms of build quality, power handling plus specs they were definitely not something to write home about.

Hope you have more luck with your samples.

Regards,

Eelco
Lol-British "build quality" in the 70s was bloody awful on cars-so shouldn't have expected much better on drive units! My old boss used to run a body shop and found welding rods tacked into B-pillars with nuts welded on so they'd rattle round bends in numerous Rovers-no wonder we no longer make much of anything!

Mine do seem ok, though haven't really tested them much other than visual and pushing the cone in and out-no rubbing I can find-but trying to recall the Fs of my drivers I'm sure they were well out from each other!
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Old 16th September 2011, 08:16 AM   #13
metako is offline metako  Australia
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Dave, you wouldn't have any ZMA and FRD files for the SP1044 as well as the SP1003/B110 and SP1032/T27 would you? I'm trying to learn Speaker Workshop and am having trouble creating my own ZMA and FRD files from the frequency and impedance graphs I've been able to find (including ones you've posted). I haven't the fascilities to measure my speakers and there seems to be a paucity of raw files and graphs on the net for these classic drivers, which surprises me.

Last edited by metako; 16th September 2011 at 08:45 AM.
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Old 16th September 2011, 08:43 AM   #14
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No sorry.

dave
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Old 16th September 2011, 08:48 AM   #15
metako is offline metako  Australia
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OK no problem.
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Old 16th September 2011, 09:44 AM   #16
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Sorry, forgot to take pics (old school friend came round last night-too much curry and beer) but did remember to email myself the T/S I pulled off the two drivers:

As you can see there are some quite large variences! Speakers had been stored in the same place, same test conditions, I made 5 measurements on each driver and will average them-but they were all close to those above.

How do you insert an excel page? I keep trying, looks ok when I do it but as soon as I save the post it jumbles it all up
Attached Images
File Type: jpg b139.JPG (62.0 KB, 296 views)

Last edited by TheBaronGroog; 16th September 2011 at 09:54 AM. Reason: excel spreadsheet not pasting properly
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Old 16th September 2011, 09:56 AM   #17
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Oh, one other thing-I worked out the diameter of the driver(needed for the added mass method) by measuring length and width and averaging them-any better way to do it?
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Old 16th September 2011, 10:22 AM   #18
Salas is offline Salas  Greece
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Ellipse Surface Area - Engineers Edge After finding the elliptical driver's surface (354cm2 ?), you can assign a diameter for same circular surface in the program.
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Old 16th September 2011, 10:35 AM   #19
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Technically not an elipse (i did try searching this) it's more like two overlapping circles joined together like the pic below
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File Type: jpg b139-2.JPG (9.1 KB, 279 views)
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Old 16th September 2011, 10:41 AM   #20
Salas is offline Salas  Greece
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It should near it, but lets accept KEF's 55sqin or 354cm2, that would include half way to surround, and it would be 212.35mm D if circular. There is also the later paper with FR charts that states 349cm2, still very near. Do the pure ellipse A=piAB on the B139 including half surround in either direction to see if it yields near what KEF gives, just for fun.
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