Ashly nX1504 Operating Manual page 36

Operating Manual - nX, nXe, and nXp 150W/75W Power Amplifiers
4) Crossover Functions
The crossover tool offers a convenient way to configure amplifier outputs. Depending on whether the desired crossover
is two, three, or four-way, all high-pass (HPF) and low-pass filters (LPF) are automatically placed on output channels. Initial
crossover frequencies are assigned with the default filter type of 24dB/oct Butterworth, both of which can be changed. In the
frequency response display screen, all currently loaded filter frequencies are available for editing by left-click dragging a HPF/
LPF node, or by using the text boxes below the GUI.
Warning: High pass filter determines the lower frequency limit of the signal, while the Low Pass Filter determines the
upper frequency limit. Be careful not to accidentally send low frequency signals to high frequency drivers. Check the loudspeaker
specifications to determine a safe operating frequency range.
Available Filter Types:
Bessel - 2nd, 3rd, 4th and 8th order (12, 18, 24, 48 dB/octave)
Butterworth -2nd, 3rd, 4th and 8th order (12, 18, 24, 48 dB/octave)
Linkwitz-Riley -2nd, 4th and 8th order (12, 24, 48 dB/octave)
The following summarizes the three primary filter types offered:
Butterworth
Butterworth filters individually are always -3dB at the displayed crossover frequency and have a "maximally flat" pass-
band and sharpest transition to the stop-band. When a Butterworth HPF and LPF of the same corner frequency are summed, the
combined response is always +3dB. Note that when 12dB/octave Butterworth HPF and LPF filters are used to create a crossover,
the polarity of one of the outputs may need to be inverted to compensate for the phase shift of the filter.
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Four-Way, Three-Way, and Two-Way Crossover (outputs only)