SpeakerTalk

Mike P · Introductory Contributor Joined: 18 Jun 2015 Posts: 2

This is my first post on this forum so first of all, a quick hello to everyone Smile

A good friend of mine has recently inherited some large vintage KEF speakers. I understand they are the original version of the Carlton from 1967-1969.

The speakers haven't been run in at least a decade and I've advised my friend not to test them until we've checked that the driver surrounds are not rotten. I've also advised him that the crossover capacitors will need replacing.

The trouble is that I can't see an obvious way of removing the grills to check the condition of the drivers. Can they be removed?

Any information on these old giants will be gratefully received!

audiolabtower · VIP Contributor 500+ Joined: 06 Jan 2009 Posts: 686

Those are very rare speakers, especially if still working. No idea how the grill comes off, sorry. The Spendor BC3 had a similar arrangement where you could not see how to possibly get the grill off, there the badge came out, and there was a nut underneath to remove the bottom wood panel, the rest of the grill was then easy... no idea if this Kef is the same, I've never seen one.

It possibly has a B1814 bass driver (type 6179) which could be a very big flat rectangular drive unit (14in x 18in) with polystyrene diaphragm laminated with aluminium foil. The mid unit was a M65 (type 6432), a 2.5in aluminium then plastic dome, with a long (one yard) concertina plastic cylinder at the rear filled with damping material to load it. Finally a very early T27 tweeter (type 6340).

That carlton did not last long because the M65 had production and reliability problems and very soon Kef made the famous B139 elliptical bass unit and original B110 midrange speaker with bextrene cone and these were much better drivers so then many generations of speakers were made with these drive units and their updates through the 70s and 80s.

Mike P · Introductory Contributor Joined: 18 Jun 2015 Posts: 2

Thank you for the reply.

Do you think it would be safe to give them a test without first examining the driver surrounds? I've no idea if the surrounds on the B1814, M65 and T27 are prone to perishing or not.

audiolabtower · VIP Contributor 500+ Joined: 06 Jan 2009 Posts: 686

As far as I know they are plastic or cloth impregnated surrounds, not foam as on some of the 90s drivers, needed for low moving mass in the coupled cavity designs. It was only after a decade or so that the foam disintegration became known. If the drivers are gone there is no hope of repairing them to original specification. The bass unit would have nothing "off the shelf" to repair it with, it would have to be be a hand made job! As I said these must be very rare, especially in that good looking condition. I would hook them up and give them a try gradually increasing volume carefully.

speakerguru · Posted: Sat Jun 27, 2015 10:13 pm Post subject:

Very rare indeed and way before my time at KEF. I'm sorry I can't be of much help other than to confirm no foam surrounds to worry about with those drive units.

Before you play them for real, you do need to dis-assemble them to see if any glue joints are coming apart after all this time.

T.O. Chef · Posted: Tue Jul 21, 2015 9:37 am Post subject:

I'm a bit late to the party on this, but if there's still interest perhaps I can assist.
The cabinet design, right down to the cloth used and the wood trim on the bottom section of the baffle is identical to smaller pair of 2 way speakers had had from the smae Kef era.... K2 Celeste I believe
Those used an B-139 (original version) and a T-15 dome tweeter.
The baffle does not come off from the front!! Careful, don't try to force it.
Access to the innards is by removal of the rear panel. Be careful there too as the stufing inside is pink fiberglass, and a mask / gloves are recommended! The stuff sent a cloud of fibers in my face when disturbed!

The drivers and filter can be easily removed from the rear.
There should be B1814 bass driver, an M65 midrange (whatever that is), and a A6430 T-27!

That bass driver must be a real antique and irreplacable. I hope you will post pictures of the various parts. Many here would love to see them.
_________________
Music is food for the soul.

darkmatter · Posted: Wed Oct 28, 2015 1:12 pm Post subject:

I have been lucky enough to pick up a pair of Carltons recently in very good condition.

Thay are soon to be set up in my main system joining Spendor BCIII and SA3 monitors.

Just found a pair of KEF LS5/1AE monitors which I will ost in a separate thread

Much fun to be had soon Very Happy

Simon