KEF 104B crossover schematic needed !

The 104aB was one of the first reference models part designed, but more importantly matched by computer. The drivers were measured and matched, the capacitors measured and inductors wound to suit. All parts matched by computer to give a result central to the design frequency response. Any change in capacitor or inductor type, will change Q or series resistance taken into account by the design and lead to a different result to the original. The SP1039 was the best B200 Kef ever made, a special high power long throw version with short coil in long magnet gap for low distortion. In the original reviews it was very highly rated, second only in subjective response to the Spendor BC1 (I have/had both).
 
Bit of a thread revival here as Deano replied to a post from 2016...

Have used my 104ab's daily for about six years now, great speakers. Little known secret is they make a fantastic near field setup in small rooms.

Was perfectly happy with them until recently when i stumbled upon a pair of 104/2's a price i couldn't refuse. That's my next project to restore those and move into the 1980s :)
 

Attachments

  • 104ab.JPG
    104ab.JPG
    851.1 KB · Views: 317
Thanks for the reply, I don’t know why I considered rebuilding without the PR’s.. Maybe to get smaller boxes ?? Never got round to really rebuild a set.

Anyway, I still use the 104 aB’s in the studio, now with a Yamaha s501, sounds great!

Hope everyone is still allright health-wise.
Hang in there!
Greetings Hendrik from the Netherlands
 
I just reworked a pair of 104ABs. The glue was bad anthe driver support wasn't even touching the driver. I took small 1/4 round and reinforced everthing and replaced the caps. The resistors were dead nut 3-10Ohm so I left them. I also made some other bracing between the driver and passive as it was the weakest point there. I Abed them with my harbeth super 5s and I'll be damned if they didn't give them a run for the money. The 5s are still better as they should be, but not when you think i have $500 in the 104 and 6K in the Beths.

I was floored to hear how good they are with the original drivers and some small upgrade work.

JT
 
I started ramping up the volume to test and both T27s are crackling a bit, without overdriving them. It mightbe x-over, but I need to do some more testing. If the x-over is ruled out, I will, for sure get in touch with Falcon and get new drivers as I really love the sound of these and I don't have that much in them.

More tomorrow... I understand why people love, or not the BBC sound, I am one who loves it. :)


EDIT: Nevermind, I don't know why, but it's AMAZON! I had some stuff like this before and went to ROOn and it is perfect. $()#$+@$
 
Last edited: