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KEF Tweeter equivalency table

 
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oldandintheway
Junior Contributor 10+


Joined: 16 Mar 2018
Posts: 14

PostPosted: Fri May 04, 2018 8:11 pm    Post subject: KEF Tweeter equivalency table Reply with quote

With the Tweeters becoming difficult to find (i'm looking for an NT25 SP1240) is there an equivalency table somewhere which identifies diameter etc? Just wondering id KEF used similar drivers in different cases, hence the differing part numbers.
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SaSi
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Joined: 24 Aug 2008
Posts: 236

PostPosted: Fri May 04, 2018 8:41 pm    Post subject: Reply with quote

Hi, I'm trying to compile a list, rather a cross reference between SP numbers and descriptions as well as systems in which they were used. As far as real specs and equivalences, that's rather tough to break.

The SP1240 is an NT25 4Ohms coaxial tweeter used in the C75 and C95 as well as the Reference 105/3.

It's a rare beast as it is one of the first generation center pole tweeters for Uni-Q drivers and later on they standardized on 19mm, hence the NT19 "blanket name" for them with different SP numbers again.

Another NT25 tweeter that goes under the NT25 scheme of things is the SP1262, used on the C85 and then there is also an SP1353 that was used on plenty of more recent speakers as well as the KEFKIT60, 80 and 90, so it may be more widely available.

Whether they are equivalent in performance and specs (i.e. sensitivity, resonance frequency and voicing, I have no idea.
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oldandintheway
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PostPosted: Fri May 04, 2018 8:43 pm    Post subject: Reply with quote

Oh, that's a good idea especially with the newer ones. Was the '19' a size (19mm)? I think it may be, but not sure. I guess in a pinch a 19mm could be used with a black spacer around it.
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SaSi
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PostPosted: Fri May 04, 2018 9:16 pm    Post subject: Reply with quote

The NT19 name comes from the size, in the same way as B200 means bass unit 200mm and B160 means the same but for 160mm.

Replacing an NT25 with an NT19 may be a bit adventurous or not. You may have trouble matching output levels with the midrange.

But experimenting is fun and as long as it doesn't cost you much, enjoy.
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speakerguru
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Joined: 18 Nov 2005
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Location: Green Hut, Tovil

PostPosted: Sat May 05, 2018 10:12 am    Post subject: Reply with quote

SaSi wrote:
The NT19 name comes from the size, in the same way as B200 means bass unit 200mm and B160 means the same but for 160mm.


Not quite right but sort of... KEF naming changed over the years. Engineering and Marketing departments argued and made it up as they went along...

An NT19 tweeter has a 19 mm (3/4") voice coil diameter, whereas a T27 also had a 19 mm dia vc but the name came from its overall diaphragm diameter of 27 mm.

A B200 woofer has a nominal 200 mm (8") overall diameter, unrelated to its voice coil size, which could be 1", 1.25" or 1.5".
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SaSi
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PostPosted: Tue May 08, 2018 7:50 pm    Post subject: Reply with quote

OK, so it looks like for the coaxial tweeters, naming came from the VC size where for all other drivers, it came from the dome or cone size.
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