EMI Elliptical Drivers

[Martyn Miles]

I have acquired a pair of unusual PWB speakers which, I understand from PWB, were fitted with Kef B139 drivers.
They were bought new in the '70s from an audio dealer in Richmond by the person I've bought them
from.
He has never removed the grilles until I asked for pictures.
EMI bass/mid. drivers have been fitted in place of the '139s.
The EMI elliptical driver was well thought of, so perhaps the dealer in Richmond modified them before the sale took place.
I am picking them up soon, so it will be interesting to give them a listen...

[struth]

might have a set of 139's if your not happy with the emi's. Most of their stuff was good though... good luck

[walpurgis]

Show us a piccie.

I would not be surprised if PWB tried various drive units, so the EMIs may be original.

[Martyn Miles]

Show us a piccie.

I would not be surprised if PWB tried various drive units, so the EMIs may be original.

I have been in touch with May Belt of PWB and sent her a picture of their NS2 speakers that I'm collecting today.
PWB's archives show the NS2 had a T27 and a B139.
The NS4 had four (!) T27s and a B139.

The ones I bought look as though they have a T52 tweeter, but I will find out for sure later today.
It's all rather intriguing...

[Martyn Miles]

I have them up and running and they're remarkably good.
The EMI driver ( which is coated ) is quite transparent and the T27 is well, a T27.
A good tweeter...

The bass end is a little 'wooly' as the cabinet is quite resonant.
Considering I was listening to Harbeth P3-ESRs earlier, these PWB's are excellent.

I am still intrigued that PWB told me that a Kef B139 was fitted to this model.
Did the Retailer modify them?
The seller confirmed that he never ever took of the grilles.

Martyn.

[Martyn Miles]

I have looked closely at the drivers and there is a gap around the EMI units which is filled by the ( now crumbling ) putty.
The EMI driver was removed and a cut-out for the B139 is there on the baffle.

Whoever fitted the EMI units did a good job.
Screw inserts and a wooden block between the back of the driver and the cabinet rear panel.
Shades of my Radford Bookshelves there...

Struth of this Parish says he may have two B139s, so I may try those.
If all's well the EMI units might be of interest to speaker builders/repairers.

Martyn.

[spendorman]

B139 cossing over to a T27 might be a problem, T27 does not really go low enough. B139 to T15 is even pushing it a bit.

Any chance of pictures, especially of the bass/ mid units? The part number might be 92390 followed by some letters.

[struth]

Just checked and i must have moved them on as i cant find that pair or the tweeters...sorry martyn.. Only got a passive rad a set of 3 point 200,s now, plus a plethora of full range drivers i really need to move on. Oh and a set of horn tweeters and ribbon ones. No wonder i cant get moving out there.


http://www.ebay.co.uk/itm/KEF-B139-S...kAAOSw6btXSI2d

A few on bay.. These are the cheapest

[Martyn Miles]

B139 cossing over to a T27 might be a problem, T27 does not really go low enough. B139 to T15 is even pushing it a bit.

Any chance of pictures, especially of the bass/ mid units? The part number might be 92390 followed by some letters.

Please send me your email address and I'll you send pics. of the EMI drivers.

They have numbers printed on the chassis.
I'll check them and post here, and/or email you later.
I think I'll go for the '139s Struth showed me on eBay and sell the EMI units.
There seems a market for them.

By the way, Radford crossed the B139 over to an HF1300 successfully.

Martyn.

[walpurgis]

By the way, Radford crossed the B139 over to an HF1300 successfully.

Martyn.

Not very successfully I'm afraid. The B139 simply does not do midrange. Above about 800Hz it starts entering a nasty honk zone.