AP25 Installation and Operating Guide
Page 88
AP25 Installation & Operating Guide
Document # 9301H79500 Ver. 1.00
4.3.8.4.2.
High Pass and Low Pass Shelf
The High Pass and Low Pass Shelves are for active crossover systems. The High Pass is the
portion of the sound spectrum that is going to find its way to the top-end compression driver.
The Low Pass is the portion of the sound spectrum that is going to find its way to the mid-
woofer.
Since there are 16 output channels available, you have the option to use them any way you like.
Suppose you actually have six channels of incoming sound, then you have 10 other D/A
converted outputs that can be used as crossovers. All you need to do is identify which channels
will be used as crossovers. Setting up your system in this way, lets you do away with passive
crossovers. Although you would need more amplifiers, it does give you much tighter control of
your system.
You can also decide how steep the High Pass or Low Pass cut-off is. The conventional values
are 6, 12, 18, and 24 dB. As the numbers go up, the cut-off is steeper.
Note:
Set up the crossovers before you run the Dirac software. The Dirac software will
fine-tune the characteristics of the crossover point. If a driver has issues with time
alignment, or encounters an aberration of some sort that can be measured, it will do its best
to correct for it. It will also adjust all the amplitudes to their appropriate values to get a
smooth response within that range.
4.3.8.4.3.
Routing/Crossover setup screen
Menu (System) > Formats > Channel Profile > Routing/Crossovers
Figure 67. Crossover Setup Screen
The matrix on the left displays the input channel – to – output channel mapping.
To make assignments, first dial in the output channel, then edit the input channel and other
options.
1.
Dial in the output channel number. Touch the field and use the adjustment knob to change
the setting.
2.
Then edit the input channel. Input channel may be assigned 1-16. Output channels may
share the same input.
3.
Set Low pass filter. Options are Off, Lnk-Rly (Linkwitz-Riley) 6, 12, 18, and 24
dB/octave; Butwth (Butterworth) 6, 12, 18, and 24 dB/octave; and Bessel 6, 12, 18, and 24
