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ITT-KB KS660 Speakers

 
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ITT-KB KS660 Speakers

Post by crackle » Mon May 02, 2016 11:00 pm

In between coats of varnish and waiting for some more miniature LED's I got hold of these speakers over the weekend.
They are NOS still boxed ITT-KB speakers from 1971-2. They consist of a Fane 12 inch bass driver, a 6 x 4 mid range driver and a 3 inch cone driver.
Although they look new, with no sign of damp damage, (they had been stored in a loft) when the seller tested them it was found that one of the speakers was working, but the other was almost dead, only the mid range driver was working.
As they were fairly local to me I went to look at them anyway, and after a few tests determined the speech coils were all OK. I found the bass driver cone very stiff in fact it would not move until I pushed harder and then it suddenly gave way with a horrible crunching grinding noise. I was not very certain I still wanted the speakers, but anyway we agreed a price (to get them out of his way) and he helped me put them in the boot of the car.

The seized bass driver was a Fane manufacture and looked fairly business like with a nice still pliable outer rubber suspension. There were 4 bolts holding on the magnet assembly to the cast alloy basket, which with a bit of persuasion came undone revealing the cause of the problem.

The cleaning and repair to the first speaker has gone well and it is now working nicely.
The following photos were taken of the second bass driver which although working was also rubbing badly. The seized speaker was very much worse around the speech coil gap.

What is this corrosion. Was it tin plate or zinc plate (galvanised) which has caused the problem. My suspicions are that it was zinc plated as I seem to remember seeing some galvanised items on my boat end up like this.
fane 1.jpg
fane 2.jpg
What did Fane use for the magnet cover?
fane 3.jpg
fane 4.jpg
fane 5.jpg
fane 6.jpg

Mike

 
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Re: ITT-KB KS660 Speakers

Post by marc » Mon May 02, 2016 11:15 pm

Hi Mike,

Fane, a bit of Batley's finest and just down the road from me. :)
Looking closely at the plastic cover doesn't it remind you of a plastic plant pot drip tray ? Even the inside colour is right. :aaq

Marc.

 
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Re: ITT-KB KS660 Speakers

Post by crackle » Tue May 03, 2016 10:22 am

Now I know where the idea for plant pot drip trays came from. :bba
Both bass drivers repaired and are working very well.
Both the mid range drivers had also suffered with age. The plastic outer suspension on both had come unattached from the paper diaphragm, mainly as a result of the glue going tacky, but also I suspect because it may have shrunk very slightly with age.
mid 1.jpg

In order to reattach it I cut slots part way into the lip of the suspension to allow it to reach the diaphragm. I used superglue to stick it to the diaphragm, as this would activate and harden with the tacky glue.
I also did this on the other mid speaker and the diaphragms are now firmly attached and move smoothly over their limited travel.
ITT-KB_mid_driver.jpg
mid 3.jpg

The tweeters both seemed OK.

Put back together and tested they sounded nice. Speech was clear and rich toned, I thought music on Classic FM sounded very good with the orchestra coming through in crisp and rich tones.
ITT-KB_KS660_inside.jpg
The copious acoustic wadding has been removed for this photo.
ITT-KB_KS660_side.jpg


Then I compared one with my Leak 2060 speakers and put the ITT speakers back in their original boxes.
Mike

p.s. It just goes to show you don't want to take it for granted that something is working correctly when it is described as NOS, unopened and still in the original boxes..
I was lucky and had the opportunity to see the speakers before I bought so I knew they were faulty.

 
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Re: ITT-KB KS660 Speakers

Post by PYE625 » Tue May 03, 2016 10:56 am

marc wrote:
Looking closely at the plastic cover doesn't it remind you of a plastic plant pot drip tray ? Even the inside colour is right. :aaq

Marc.


To be honest, on first glance, that's exactly what I thought it was :ccb

 
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Re: ITT-KB KS660 Speakers

Post by Niall » Tue May 03, 2016 11:58 am

Are those sealed or rear ported?

I notice there is no enclosure for the mid or HF drivers, so the bass will shove the cones about which won't sound good, particularly if they are sealed enclosures.

 
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Re: ITT-KB KS660 Speakers

Post by Cathovisor » Tue May 03, 2016 1:27 pm

The mid and HF drivers are enclosed by their chassis; but I doubt they would be subjected to the sort of energy that a decent amplifier would be capable of. My speakers at home have the mid and HF drivers in a separate rotatable enclosure, but then they need to be: the LF drivers are two 8" units per cabinet with a maximum rating of 600W... :bba

 
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Re: ITT-KB KS660 Speakers

Post by marc » Tue May 03, 2016 3:34 pm

Cathovisor wrote: the LF drivers are two 8" units per cabinet with a maximum rating of 600W... :bba

That would still take ages to boil a kettle but at least you'll be nicely deaf by the time your brews ready :aac :bba

Marc.

 
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Re: ITT-KB KS660 Speakers

Post by crackle » Tue May 03, 2016 4:08 pm

It is a sealed "infinite baffle" enclosure. The treble driver, has a sealed metal basket at the back, the midrange driver, which has an open basket, has a plastic hood bolted over the speaker to create a separate enclosure for it.
These speakers are only rated at 20 watts, so would probably be offered as an option to go with one of the ITT Unit Stereos of the time, e.g. http://www.radiomuseum.org/r/ittgb_twen ... 250fm.html

Mike

 
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Re: ITT-KB KS660 Speakers

Post by Cathovisor » Tue May 03, 2016 4:53 pm

marc wrote:
Cathovisor wrote: the LF drivers are two 8" units per cabinet with a maximum rating of 600W... :bba

That would still take ages to boil a kettle but at least you'll be nicely deaf by the time your brews ready :aac :bba

Not if it was a travel kettle - they're nice and small.

http://audiolandpro.com/B-W-MATRIX-802- ... _1371.html


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