Kef Concord loudspeakers.

[Dave the bass]

A lovely fellow-skater mate's son has got a pair of these...


and from the back...


Neither of them know much about them other than what an obligatory Webbernet search throws up, B139 Bass/mid units, made in 1967-ish etc etc etc.

Anyone here had any experience of them? Any cop?

DTB

[Scottmoose]

Probably of most interest to a collector, or perhaps to salvage the drive units (providing they're in good shape) for the same reason.

[pre65]

Probably of most interest to a collector, or perhaps to salvage the drive units (providing they're in good shape) for the same reason.

And you might find a good use for the cabinets on a cold winters evening.

The B139 bass units should sell reasonably well on e-bay, depends on the SP number.

[Mike H]

Oh those are them strange oval flat-faced things int-they?


 

[chris661]

Yeah, but they're usually used in a 3-way. There's been one or two people use them on diyAudio implemented that way.

For a kick off, replacing any electrolytic caps in the crossover would improve the sound dramatically. After that, new cabinets with lots of bracing (perhaps go for a ported or TL design...).

[andrew Ivimey]

Alas, these speakers, I knew them.

Of course the three way design which was most often used as B139, B110 and T27 was a classic repeated many times by different speaker designers; the most enduring was probably the Kef Concerto.

But what sounded fab and groovy or sedate and authoritative depending on your musical bent, in the 1970s just isn't what is considered such today.

Soft and spongy, coloured if a little attractive, even the dear old Concertos.

But 11 out of 10 to Kef for constantly trying, changing, innovating and generally pushing the envelope in trying for sonic excellence. Most of them used to do it in those days and I don't believe it was just a marketing ploy.

Still, this particular beast had the B139 which has great potential but surely not up to 1.2kHz or wherever this crossover, er crossed over - can't remember! and that tweeter had a lot more work to do than the dear old T27; but still it worked, though as I said, above, soft and spongy; unless well cranked up and then nothing matters!

So, if I chanced upon a pair I would check'em out; not chuck'em out! and probably just use the box and the B139 with a cunning implementation of some exotic and rare tweeter sitting on top of the box; bring the crossover down to say 800Hz and use a Manger, Heil or even something else fabulously rare for the mid to tops.

(I'm still looking to do this , you see;-) )

[steve s]

i have a nice pair of kef concerto's, the speakers don't sound very good at all really..
but as scott has pointed out the drivers are quite sought after

similair to the bbc design speakers LS whatevers

mine have the b139/d300/t127

i would guess the cross over caps are the issue.. they are from 1972..

steve

[ed]

ahhhhhh memories

I still have a pair of carlton lll in a loft somewhere:

T33 (sp1074)
B200G (sp1075)
BD138B (sp1082)

IIRC utilise the famous KEF 'C' config to take the tuning down from somewhere like 47hz to something like 33hz......

memory tells me they are as omib describes...

offers?

[pre65]

My Kef Kit3 (DIY Concertos) that I built in the 60s (my first DIY effort) eventually got sold on e-bay, although the buyer only wanted the drive units. The chipboard cabinets still clutter up my conservatory !! I must learn how to dispose of old crap, but this winter, one cold night, they may go for the greater good of me keeping warm.

[Dave the bass]

I'll pass on all yer comments to my skater-chum (and hence his Son).

Ta for info Gents.

X

DTB

[Mike H]

According to my ancient Wilmslow Audio catalogue (occasionally comes in handy, like now )

B139B LF type SP1044

Dimensions: 30 x 21 cm
Weight: 3.85 kg
Nominal impedance: 8 Ohms
Power rating: 100W programme
Freq. range: 20 - 1000 Hz
Voice coil dia.: 55 mm
Recommended Xover freq.: 400 Hz
Fundamental resonance: 25 Hz
Sensitivity: 96 dB @ 1m

Best suggested combination would indeed seem to be 3-way with a B200G midrange and a T33A tweeter

If the drivers sill have any working life left might be worth a rebuild


 

[planet10]

The Concord had B139 XOed to T15 at 1kHz, The B139 has a nasty resonance right near there and even using it as high as 400 Hz is pushing it. To get the tweeter to go that low its extension is not all that good.

Factory data sheet here. http://www.t-linespeakers.org/drivers/b139.html

A pair of B139 make a nice woofer



http://www.t-linespeakers.org/projects/vProjects.html

dave

[chris661]

Could this be a candidate for a FAST system?

[steve s]

B139B LF type SP1044

Sensitivity: 96 dB @ 1m

I bet thats not at 2.83 volts... its not possible...

my speakers are nearer 90 dbs poss high 80's

surely they would sound much cleaner if they where 96 db drivers and would not go so low...?

[ed]

http://cgi.ebay.co.uk/KEF-B139-SP1044-D ... 0607608771

and this

http://www.hifiloudspeakers.info/Anatom ... itsp1.html