It is commonly thought that there will always be a phase difference of 180° between the outputs of a (second-order) low-pass filter and a high-pass filter having the same crossover frequency. And so, in a 2-way system, the high-pass section's output is usually connected to the high-frequency driver 'inverted', to correct for this phase problem. For passive systems, the tweeter is wired with opposite polarity to the woofer; for active crossovers the high-pass filter's output is inverted. In 3-way systems the mid-range driver or filter is inverted. However, this is generally only true when the speakers have a wide response overlap and the acoustic centers are physically aligned.
it is commonly thought that there will always be a phase difference of 180° between the outputs of a (second-order) low-pass filter and a high-pass filter having the same crossover frequency and so in a 2-way system the high-pass section's output is usually connected to the high-frequency driver 'inverted' to correct for this phase problem for passive systems the tweeter is wired with opposite polarity to the woofer; for active crossovers the high-pass filter's output is inverted in 3-way systems the mid-range driver or filter is inverted however this is generally only true when the speakers have a wide response overlap and the acoustic centers are physically aligned