Can the PHOENIX be build with passive crossovers?
A40 – Practically speaking, the PHOENIX cannot not be driven from a single stereo power amplifier even if you had succeeded in designing a passive crossover filter that applies the same voltages to each driver as shown by the frequency response curves A, B and C of xo_eq2.jpg and the associated non-minimum phase response for C. The problem resides in the large amount of equalization that is required for dipole operation. For example, between 30 Hz and 400 Hz the amplifier power that is available to the woofer and midrange differs by 20 dB or by a factor of 100. Thus if you used a 100W amplifier to meet the low frequency needs, then only 1 W would be available around 400 Hz. That clearly is not sufficient. A wasteful 99 W is dissipated as heat in the resistors of the crossover. The obvious solution is to use a dedicated power amplifier for the woofer with an active crossover/equalizer between woofer and midrange. This leaves a passive crossover between midrange and tweeter. Now the driv
