ABSTRACT
The response of the third-order Linkwitz-Riley crossover alignment is shown in Figure 4.30. The summed amplitude response has a dip of exactly −3 dB at the crossover frequency, and each filter output is at −6 dB. In this case, reversing the phase of one output does not convert it into a hump, but gives exactly the same response with the same dip, because of the differing phase relationships. As we have seen, a hump in the response can be flattened by using a frequency offset that lowers the cutoff frequency of the lowpass filter, and raises the cutoff frequency of the highpass filter. Clearly a dip cannot be dealt with like that, as pulling apart the crossover frequencies, as we have done before, is just going to make the dip deeper.
