SpeakerTalk

hans 67 · Posted: Tue Dec 30, 2003 10:54 am Post subject: RR 103.2 crossover?

Hello all,

has anybody the schematic of the RR 103.2 crossover?

Is it equal to the CS3 crossover (except the extra protection circuitry in the RR 103.2)? I have the schematic of the CS3. I think the drivers are equal (is writen in the CS3 brochure).

Greetings, Hans

hans 67 · Posted: Tue Dec 30, 2003 6:05 pm Post subject:

Hello all,

and how about the crossover in the 303? How does that compare to the ones in the CS3 and the 103.2?

Greetings, Hans

SteveB · Junior Contributor 10+ Joined: 31 Dec 2003 Posts: 11

hans 67 · Posted: Sat Jan 03, 2004 8:21 pm Post subject:

Thank you Steve,

I have received your e-mail. Nice work.

More people are probably interested. Is it possible to put it on this site (if it is there already, then I could not find it)?

Greetings, Hans

hans 67 · Posted: Sat Jan 03, 2004 10:19 pm Post subject:

Hello all,

I have seen in the schematic from Steve that the CS3 and the RR 103.2 crossover circuits are different.

Is it possible to use the CS3 crossover in the RR 103.2?

Why? All the original crossovers use a lot of electrolytes. And Falcon sells replacement crossovers for the CS3 with polyester capacitors (except the large 300 uF ones).

Greetings, Hans

hans 67 · Posted: Sat Jan 03, 2004 10:25 pm Post subject:

Hello all,

it is interesting to see that the RR 103.2 crossover uses a notch filter for the B200 and the CS3 not.

Is this notch filter needed?

Greetings, Hans

SteveB · Junior Contributor 10+ Joined: 31 Dec 2003 Posts: 11

Hans,
I've sent the crossover circuit to Terry for possible inclusion on the site, along with several others.

Interesting to note that the crossover topology for the bass unit in the R103.2 is exactly the same as that in the R101 (which uses the B110B). Obviously the components have different values but the same circuit layout is used. Perhaps the Reference crossovers are more complex because KEF were striving to make these speakers the very best, with as smooth a frequency response as possible, regardless of component count.

I don't know if the crossovers can be interchanged between R103.2 and CS3, or if the notch filter is needed. Perhaps try it and see if you can hear a difference?

Regarding polyester capacitors, these are deemed to be superior to electrolytics (lower distortion) and they have a much longer life time.

hans 67 · Posted: Sun Jan 04, 2004 10:23 pm Post subject:

Hello Steve,

yes, it is the lifetime I am worrying about. Electrolytics lose their capacitance. And that can be a problem with the notch filter (after 20 years), which must have a good defined frequency. Without the notch filter the CS3 has already a pretty flat frequency response. And the housing is not that different. Thus it must be possible to replace it with that of the CS3 (but it will not be a RR 103.2 anymore).

Can I reach the crossover when I remove the B200?
Where is it located?

Greetings, Hans

SteveB · Junior Contributor 10+ Joined: 31 Dec 2003 Posts: 11

Hans,
it is easy to access the crossover. Remove the B200 and disconnect the wires (these are push fit connectors on mine). The crossover is mounted in the base of the cabinet. Lift up the acoustic foam and disconnect the connector on the right hand side (this disconnects the B200, T33 and LED on the front). Disconnect the two input wires (black and white) at the back also (again, easy push on connectors).

The crossover is held in place by 4 nuts - one at each corner. Use a nut socket (9/32 inch or 7mm) to undo these. You can then lift out the crossover.

Remember to put connections back correctly when re-assembling.

Jake · Posted: Sun Mar 21, 2004 7:43 pm Post subject:

hans 67 · Posted: Wed Mar 24, 2004 8:45 pm Post subject:

Hello Jake,

no idea? I had no time.

Greetings, Hans