Crossover with low-pass filters of linear phase response and a monotonically decreasing passband amplitude response (it starts rolling off at DC and continues throughout the passband). Linear phase response (phase shift vs. frequency) results in constant time-delay (all frequencies within the passband are delayed equally). Consequently there is no overshoot or ringing resulting from a sudden transition between signal levels. The drawback is a slower frequency roll-off rate.
A filter type with a Q = 0.58 that produces a nearly flat amplitude response and group delay with a Ãƒ?5 to-7 _ dB crossover point.
A crossover design that places emphasis on phase and transient response over reducing ripple.