Yes, I have changed the polarity when removing the passive crossover network of the woofers. I was looking for KRELL KBX crossovers but those are no more made or available as you have mentioned already. But the crossover is not the problem here.
I have tried with good analog crossovers. I have experimented with different crossover frequencies, crossover slope, volume levels, even adding a subsonic filters as the KRELL KBX crossover provides. Still I hear the continuous background sound from woofers after the drum beat was hit on some CDs. It is definitely not the room reverberration. The woofers are really vibrating for extended period (though at a lower intensity than the sound of first drum hit) after the drum beat.
I don't know if this is acceptable to many audiophiles, but it is not acceptable to my ears. I feel very annoyed if woofers continue to make sound and do not exactly follow the drum beats. The most surprising thing is that with some CDs the heavy and deep drum beats are extactly reproduced with clean, heavy and deep bass. I have observed that about 95% (or more) of the CDs make the abnormal continuous sound from the woofers and only 5% (or less) do not. Moreover, in a particular CD some tracks do make that bad sound and some other tracks do not. By the way, I listen to pop, rock, jazz, metal, classical, and anything except rap. I am extremely puzzled that if something is wrong with the system setup, or the woofers, or the crossover setting, or associated electronics or the room, then why some tracks on some CDs can make very clean deep and heavy bass sound ?
Is it possible that 95% of CD makers did not record the bass correctly ? That is very hard to believe.
Thanks for your help