@harpo75: Excellent! Now consider using a pair of the Rythmik Audio/GR Research OB/Dipole Subs in place of the woofers in the ET LFT-8b! The OB Sub can play up to 300Hz (the ET's dynamic woofers are used up to 170Hz), and will turn the LFT-8b into a completely dipole loudspeaker.
It's easy: just leave the stock woofers unconnected at the binding post terminals, and use the controls on the Rythmik A370 plate amp as your low-pass crossover filter..The OB sub contains either two or three (your choice) 12" woofers, and is a remarkable woofer system. You can use your F12's as well, for a DIY "swarm" low frequency system.