Wayne Parham Messages: 18786 Registered: January 2001
Illuminati (33rd Degree)
I use an active crossover with 90Hz 12dB/octave low-pass slope. Sometimes, it is good to go a little higher, sometimes a little lower. Don't high-pass the mains, let them blend. The further away the subs are, the lower the low-pass frequency for the subs should be. Sometimes it even helps to reverse polarity.