11
crossoVer controls
Crossovers are groups of electronic filters
designed to control the frequency ranges
that each speaker in a system will be tasked
with reproducing. Proper crossover setup is
critical to sound quality and reliability.
The MHD600/4-24V has two individual
filters, one for the “Front” channels and the
other for the “Rear” channels. Each can be
configured as a high-pass filter (attenuates low
frequencies) or as a low-pass filter (attenuates
high frequencies). Additionally, the user can
select from a shallow (12dB/octave) filter slope
or a more aggressive (24dB/octave) slope.
Each Channel Control section contains
identical crossover filter controls.
1) “Filter Mode” Control: this switch allows you
to configure the filter for that Channel Pair
into one of two filter types.
“Off”: Defeats the filter completely, allowing
the full range of frequencies present at the
inputs to feed that pair of channels. This
is useful for systems utilizing outboard
crossovers or requiring full-range reproduction
from that pair of channels.
“HP” (High-Pass): Configures the
CH 1&2 filter to attenuate frequencies
below the selected filter frequency.
Useful for connection of component
speakers in a bi-amplified system.
“LP” (Low-Pass): Attenuates frequencies
above the selected filter frequency.
Useful for connection of subwoofer(s)
in a bi-amplified system.
2) “Filter Slope” Control: This switch allows you
to select from two filter slopes.
“12dB”: Configures the filter to attenuate
frequencies above or below the selected
filter frequency at a rate of 12 dB per octave
(Butterworth alignment).
“24dB”: Configures the filter to attenuate
frequencies above or below the selected
filter frequency at a rate of 24 dB per octave
(Linkwitz-Riley alignment).
Depending on the speaker system and the
vessel, different filter slopes may be required to
produce a smooth transition between the sound
of different speakers in the system.
In high-pass mode, the sharper “24dB” setting
will do a better job of protecting small speakers
with limited power handling. In low-pass
mode, the “24dB” setting can also help by more
aggressively removing lower midrange output
from a subwoofer system.
The shallower “12dB” octave setting
allows for more output overlap between
the speakers being crossed over. In many
cases, this will result in a smoother “blend”
or transition between speaker systems.
Experiment to find the slope or combination
of slopes which best matches the acoustic
requirements of your system.
3) “Filter Freq. (Hz)” Control:
This control selects the frequency at which the
filter begins to attenuate the signal and refers
specifically to the frequency at which output
has been attenuated by -3dB.
The filter frequency markings surrounding this
rotary control are for reference purposes and are
generally accurate to within 1/3 octave or better. If
you would like to select the filter cutoff frequency
with a higher level of precision, consult the charts
in Appendix B (page 18) of this manual.
Summary of Contents for MHD600/4-24V
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