The impedance would easily go below 1 ohms at a wide range of frequencies without attenuating resistors because of the equalization network I have going on. My amp is rated for down to 4, but less than an ohm...not sure what that would do to my amp.
Did end up fixing that problem; the maximum variation in spl (in theory, at least) should be 1.03dB, +0.57dB from the average and -0.46dB. The mean variance is +-0.20dB (that is, the mean variance plus the mean is 0.20dB above the mean).
Impedance is down from 8ohms nominal to between 8.5 and 3.3 ohms, so lets say 4 ohms nominal? I guess the efficiency of my design sucks but I was expecting that with all of the equalization I used.
Still looking for a good all-pass filter to fix the phase (does anyone know of any better explanations of lattice phase-equalizers than Wikipedia's?).
Thanks