Electro-Voice Speaker System - Manual (Page 24)

24
Input Channel Hi-Pass Filter
Use the < Select > buttons to make the top line of the Edit screen
active and the Value Up and Down buttons to navigate to the
Input Hi-Pass screen.
The first DSP block in the DC-One’s signal flow is the stereo Hi-Pass Filter. In
any sound reinforcement system, the Hi-Pass filter is crucial for maximizing
the efficiency and performance of the PA system. Both analog and digital
audio sources can include significant sub-sonic (infra-sonic) program material
and artifacts. Audio frequencies below the threshold of human hearing can
still be present at the amplifier inputs, and the amplifiers and loudspeakers
will do all they can to reproduce to reproduce them; at a great cost of power
and efficiency.
Hi-Pass filters can set a frequency, below which, signals will be attenuated or
reduced. The cut-off frequency selected for the hi-pass filter – below which
the frequencies will be attenuated - will vary depending on the program
material and connected loudspeaker system. For example, full range music
can produce frequencies down to the theoretical limit of human hearing (20
Hz), some acoustic music can be limited to frequencies above 60 Hz, and
voice-only reproduction is limited to much higher frequencies. Hi-pass filter
applications and settings will be determined by the needs of the given DC-One
preset selected for the program material and sound reinforcement system.
The DC-One Hi-pass filter offers several response curves, or slopes, to suit
the needs of the given application. Select the curve that best meets the needs
of your particular situation:
Freq - The cut-off frequency
for the Hi-Pass filter. The
frequency range is from 20
Hz to 200 Hz and is
adjustable in 1 Hz
increments. Select the
frequency setting that is
appropriate for the
attenuation slope selected
and type of program material.
Bypass – No sub-sonic or low-frequency filtering is applied. Use this to
bypass the Hi-Pass filter.
Slp - Slope or degree of attenuation.
6dB/Oct – A very gentle attenuation of frequencies below the
selected cut-off frequency; good for acoustic music that is
generally within known frequencies, but may drop below; without
much energy.
12dB/Oct – Steeper attenuation of frequencies below the
selected cut-off frequency; useful when un-expected low-
frequency material may be encountered. When 12dB/Oct is
selected, Q band is available - from 1.4 to 2.0.
HPF
For detailed
EQ plot im-
ages please
see page 45