On my classic Klipsch corner Khorns, I am not sure about the time delay issue with bi-amplification, I remember something somewhere about it pertaining more to cones that constant directivity horns…
Like the Cornwall, the 15” woofer in the Khorn bass bin is run full range. The crossover limits the signal to the mid and high range horns. I am not really bi-amping, more like passive dual-amping. I am running flea-powered Bottlehead 2A3 Paramour monoblocks SETs on the top crossover (mid and upper horns) and a 70s vintage, 48-pound Pioneer M-22 dual monoblock (think mini-Threshold) solid-state amplifier on the bass bin. The Paramours are rated for 3.5, but put out 6 watts. The Pioneer is rated for 22 extremely low THD Class A watts, but puts out 60 watts. I think it is important that the power output of the amps be similar, otherwise you get some nasty balancing issues, which are best resolved by an active crossover.
Against advice, I disconnected the top crossover network from the bottom cable connection plate on the bass bin and connected the two amplifiers to the two sets of outputs on my pre-amplifier.
I love it. The monster Pioneer has the best control of the bass of any amplifier I have heard on my big ole horns. It sounds similar to the $6k Pass X250 I heard on my walnut-oiled Cornwall 1s, with B2 crossovers - but only at low to moderate low volumes. The sweet tubes have immediacy, delicacy, soundstage and imaging. A wonderful combination so far, though I will admit I do not crank it very loud. I understand that since I am running dual amplifiers, WITHOUT an active electronic crossover ahead of the drivers, each amp receives a full range signal and therefore clips at the same point it did previously. So I am not getting the effect of 4 times more power as I would with true bi-amping, where you divide the signal ahead of the amplifiers.