4th Order Linkwitz Riley Crossover Filter
Having worked with Vifa's PL18 woofer and PL27 tweeter for
many years, I can safely say that 1,500Hz with a 4th Order
Linkwitz Riley Filter is the best crossover point as far as
sonic quality is concerned.
24dB/octave network is ideally suited for this speaker. With
the tweeter right at the edge of it's specified bandwidth,
such a steep rate of rolloff is a necessity. At the same time,
the woofer nasties beyond 2kHz would be sufficiently suppressed
Linkwitz Riley Response has some very appealing features for
crossovers. Acoustically, the two drivers sum at unity at
the crossover point. The amplitude response throughout the
passband is flat, no ripples whatsoever. At the crossover
point, it has a zero phase difference between drivers.
more information about this crossover, Linkwitz
Riley Crossovers by Rane
Corporation is worth reading. And for the man himself,
Lab. You can see some of his amazing speakers there.
an excellent software freely available on the internet, component
values calculated by Passive
Crossover Designer are displayed at Figure 22.
take a closer look at this 24dB/octave filter.