PA-CP
User Guide
15
EQUALISER
The channel equaliser allows independent
adjustment of four frequency bands. This lets you accurately
pinpoint the frequencies you want to adjust to deal with
problems such as feedback or instrument resonance, or to
creatively tailor the sound.
HF
The high frequency band has a shelving response that
cuts or boosts the higher (treble) frequencies by up to 15dB. It
has most effect from 12kHz and higher.
HM
The high mid band has a bell shaped peak/dip response
that cuts or boosts the higher mid frequencies by up to 15dB.
The centre frequency can be swept from 350Hz to 7kHz letting
you tune in to the frequency you want to adjust. Q = 1.8.
LM
The low mid band has a similar bell shaped response
that cuts or boosts the lower mid frequencies centred on
250Hz. This control is useful in dealing with boomy sounds, or
adding low end warmth. Q = 1.8.
LF
The low frequency band has a shelving response that cuts
or boosts the lower (bass) frequencies by up to 15dB. It has
most effect from 60Hz and lower.
The EQUALISER
featured in the
PA Series
is a semi-
parametric type similar to those found in top end live sound
consoles. The four band design provides frequency control far
more powerful than that found in most competitive consoles.
The +/- controls allow precise level adjustment of each band
up to 15dB (4.5 times). The LF and HF bands have a shelving
response which gradually increases or decreases the level at
each end of the frequency spectrum until a maximum shelf
level of 15dB is reached. The mid bands have a bell shape
around their centre frequencies. The width of the bell is
referred to as its ‘Q’ factor. This is calculated from the centre
frequency divided by frequency range between the points
either side where the level drops 3dB. The larger the value, the
tighter the bell.
☺
Using the equaliser
It is best to keep the adjustments
made using the equaliser as small as possible. Use the
microphones best suited for the application and ensure they
are positioned carefully for optimum pickup. Starting with
good sources makes the job of mixing much easier. To learn
about the equaliser play a good quality pre-recorded music
source such as CD through a mono channel. Start with the
controls set flat (mid position). Boost and cut each band in
turn listening how it affects the sound. With HM boost and cut
listen to the effect of turning the frequency control. The more
familiar you become with how different frequencies sound the
quicker you will be able to find and tune out resonant or ringing
frequencies, or enhance the tone creatively.
During sound check first set the channel gain to match the
source. Do this using the PFL function. Select the 100Hz filter
where appropriate. Start with the EQ flat then adjust its
controls to get the sound you want. Try not to apply too much
boost. Cut rather than boost where possible. Make gradual
adjustments to avoid feedback or unexpected surprises. If the
channel PEAK indicator flashes then turn back the gain control.
The EQ can be used to creatively enhance or correctively
improve the tonal quality of each sound in the mix. For
example, you could use HM to brighten up a guitar so it stands
out in the mix, LM to cut back the boominess of a kick drum
while using HM to enhance the snap of its beater, HF to add
some ‘air’ to a flute or to cut back a hissy keyboard, LF to add
some depth to sound effects, and so on. Tuning and cutting
HM can be very effective in notching out a ringing mic
frequency to help increase its gain before feedback.
10k
1kHz
100
30k
10
LF EQ
10k
1kHz
100
30k
10
350Hz
7kHz
HM EQ
10k
1kHz
100
30k
10
250Hz
LM EQ
-15
-20
-10
-5
0dB
+5
+10
+15
+20
-15
-20
-10
-5
0dB
+5
+10
+15
+20
-15
-20
-10
-5
0dB
+5
+10
+15
+20
BASS
TREBLE
10k
1kHz
100
30k
-35
-40
10
-30
-25
-20
-15
-10
-5
0dB
+5
+10
100Hz
HIGH PASS FILTER
10k
1kHz
100
30k
-15
-20
10
-10
-5
0dB
+5
+10
+15
+20
HF EQ
