Allen&Heath ML4000 USER GUIDE - Manual (Page 23)

ML4000 User Guide 23
EQUALISER. The channel equaliser provides
adjustment of 4 independent frequency bands.
Each has cut/boost and frequency sweep controls.
HF and LF are shelving. HM and LM are peak/dip
with switched Q control.
HF The high frequency band has a shelving
response that cuts or boosts the higher (treble)
frequencies by up to 15dB. The shelf turning point
frequency can be adjusted from 2kHz to 20kHz.
HM The higher 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 adjusted from 500Hz to 15kHz.
The width of the bell is set using the Q switch to
either wide = 1 (switch up) or narrow = 2 (switch
pressed). The higher setting has a more selective
response better suited to enhancing a narrow range
of frequencies or notching out a problem frequency.
LM The lower mid band is similar to the high mid
but provides adjustment from 35Hz to 1kHz.
LF The low frequency band has a shelving
response that cuts or boosts the lower (bass)
frequencies by up to 15dB. The shelf turning point
frequency can be adjusted from 20Hz to 200Hz.
A8 EQ IN. Switches the equaliser in or out.
Using the Equaliser
The channel equaliser can be used to creatively
enhance or correctively improve the tonal quality of
the sound. For example, to brighten up a guitar so
that it stands out in the mix, to cut back the
boominess of the kick drum while enhancing the
snap of the beater, or to notch out a ringing
frequency associated with the position of a mic on
stage to help increase its gain before feedback.
Before using the equaliser make sure you choose
the best microphones for the job and place them to
capture each sound accurately. Start with the EQ
set flat and apply only as much boost or cut as is
needed. Use low Q settings to affect a wide range
of frequencies, and higher settings for more
selective control, for example when notching out
resonances or feedback. The HM and LM bands
have an extended frequency range to overlap the
HF and LF shelves. This allows tighter and more
precise two point control of bass and treble where
needed.
Use the in/out switch to compare the original and
equalised sound. The equaliser has a flat response
and therefore no effect when all the cut/boost
controls are set to their centre detented position.
10k 1kHz 100 30k
-15
-20
10
-10
-5
0dB
+5
+10
+15
+20
2kHz 20kHz
HF EQ
10k 1kHz 100 30k 10
20Hz 400Hz
LF EQ
10k 1kHz 100 30k 10
500Hz 15kHz
HM EQ
10k 1kHz 100 30k 10
35Hz 1kHz
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