B200 (SP1014) plus Vifa D19 TD

I have coming a pair of Kef B200, and a pair of Vifa D19TD which was suggested as a T27 substitute on this forum. I like it and it's used in my Mission 761 speakers. Similar 19mm poly dome.

What would you suggest as a crossover for a 2-way in a sealed cabinet? Typical X-over frequency is 3.5K

B200 SP1014 + T27 were used in Cantor(1971), Chorale(1970), KEFKIT1(1974), Monitor Audio MA4, Linn Index Mk1, Tangent TM1, 2, 3

Chorale crossover was SP1015 or SP1016

SP1014 – constructors, small magnet, Chorale
SP1022 – Qts .41, large magnet
SP1039 – med. Q, large magnet 104, 104aB, Monitor Audio MA4, 103 Ref. Best
SP1054 – Qts .23
SP1063 – med. Q, small magnet

SP1047 (1974) Used in: KEFKIT 1(1974)
SP1054 1976 Used in: Calinda(1976)
SP1063 1976 Used in: Caprice(1977), Corelli(1976), C40(1979), C65(1979)

Attached Monitor Audio MA5, Tangent TM1 and TM2
 

Attachments

  • Monitor MA5.jpeg
    Monitor MA5.jpeg
    21.2 KB · Views: 82
  • Tangent TM1 .jpeg
    Tangent TM1 .jpeg
    22.9 KB · Views: 84
  • Tangent TM2.jpeg
    Tangent TM2.jpeg
    23.8 KB · Views: 83
frugal-phile™
Joined 2001
Paid Member
Hard to see the B200 reaching up to the D19.

The biggest failing of the Tangents (the best of the B200/T27 i ever heard) was in the upper range of the B200.

i would not `XO it higher than something like 2.5kHz.

And i do have issues with the data KEF provides to model a proper box. By that the box wants to be considerably larger than any that came to market (i have 16 x B200 SP1014, cost almost nothing).

dave
 
Last edited:
I think it should work in a reasonable fashion, but I am not 100% convinced it would give you a T27 and DN 12 crossover response of the kef original design.

It might be sensible to stick 1 ohm at the input and try 3.3uF as the first capacitor instead of the 5.6uF shown in post 6. If not quite correct then try without the 1ohm and if that still leaves a perceived gap increase to 4.7uf or 5.6uf as per the diagram.

As you know and understand measurement would make it somewhat easier to get right.
 
I think you are asking too much of the D19 Vifa. It is not happy playing that low at any volume level. The D20 would be a little better but still not ideal. KEF was very optimistic pushing the T27 that low as well. It has very low excursion and often died by breaking the tinsel leads going to the voice coil.the other advantage of a Vifa D20 is they are rebuildable. D19 are not.
 
  • Like
Reactions: 1 user
frugal-phile™
Joined 2001
Paid Member
I’d use Alpair 5.2/3 (CHN-50 if keeing the budget theme, the 16 B200s cost me $200 CAD) or The Fostex FF85wk (with at least a few easy tweaks).

XO somewhere between 350-450 Hz, enuff overlap to use a first order XO, lots of amps in the “closet", so a PLLXO. Given the clash in box sizes, maybe a sealed isobarik with an after the fact Linkwitz transform to roll off the box appropriately since first pass will be a number pulled from the air for box size.

dave
 
  • Like
Reactions: 1 user
frugal-phile™
Joined 2001
Paid Member
A further comment on the top of the B200. Its lacks in the range just below where KEF crossed them (2.5-3.5k+) was the stark difference in the Tangent TM3 and the RS4 which was essentially the same box with an Audax HD200 swapped in. Same T27. RS4 was one of my favorite speakers of the time. Others were Dayton-Wright XG8, IMF TLS50 (with KEF B200 SP1014), and the Spendor BC-1.

Moving the XO down should move the B200s deficincies out of band.

dave