Could the woofer be adapted to work with existing panel speakers – e.g. Quad ESL63?
A10 – A PHOENIX like open baffle, dipole woofer would be the ideal complement to a variety of planar, open baffle, dipole speakers ( e.g. photos at Audio Page ). The woofer channel of the crossover/eq circuit could remain unchanged for the 100 Hz, 12 dB/oct, L-R low-pass filter section of the crossover between woofer and existing speaker. The gain setting resistor ladder values (8.25k & 5.62k) would have to be modified to account for differences in sensitivity between woofer and existing speaker. Assuming that the existing speaker has low frequency extension to at least 50 Hz, but is limited in SPL capability, then the high-pass filter section of the crossover, to drive the existing speaker, could be simply formed by a second order HP with two real axis poles at 100 Hz. The filter response could be realized with two cascaded 1st order Butterworth filters or the 12 dB/oct circuit topology of xo12-24.gif, which is also used on the crossover/eq printed circuit board. Thus, you could modif
