LEM EQ152, Руководство пользователя

Страница: 19 / 28

5
Power Switch
Press this button to turn the graphic equalizer ON or OFF.
CAUTION: always make certain the sound system’s amplifiers are off.
Filter Level Controls
These sliders control the output level of each band-pass filter:
31 band models 1/3 octave 20Hz to 20kHz
15 band model 2/3 octave 25Hz to 16kHz
All models feature RFI filters and constant Q circuitry with 3% center frequency accuracy.
Center detent position is grounded for guaranteed flat response.
Filter Range Switch & Indicators
This control sets (as a group) the maximum boost/cut capability of the filter sliders as follows:
± 6dB = green LED
±12dB = yellow LED
Bypass Switch & Indicator
This control sets the Bypass mode.
In Bypass mode (red LED on) the signal is routed directly from the input to the output without passing
through any circuit (“hard-wire bypass”).
Use this switch to compare equalized and non-equalized material, or to bypass the EQ section.
Clip Indicator
This red LED illuminates if any section of the equalizer is within 5dB of clipping.
Occasional blinking of this LED is acceptable, but if it remains on more than intermittently you should
turn down either the equalizer’s level controls or reduce the output level of the preceding component
to avoid audible distortion.
Lo-Cut
(31 band models only)
This control determines the roll-off frequency of the High-Pass Filter (HPF) in the instrument.
The roll-off frequency can be adjusted from 10Hz to 250Hz by turning this knob.
Thanks to its high roll-off slope, the HPF can be efficiently used to cut down the “HUM” noise from
preceding instruments or to prevent the low-frequency resonance while the speakers are installed in
an enclosed acoustic environment.
Hi-Cut
(31 band models only)
This control determines the roll-off frequency of the Low-Pass filter (LPF) in the instrument.
The roll-off frequency can be adjusted from 3kHz to 50kHz by turning the knob.
Thanks to its high roll-off slope, this LPF can be effectively used to cut down the high-frequency noise
from preceding instruments, or especially used to roll-off high frequency sound to obtain a more
natural sound in acoustic situations.
Level Control
This knob controls the level of signal coming into the instrument.
Unity gain can be set by turning this knob to its center detent position.
Turn this control down if the Clip LED illuminates steadily (meaning excessive input signal).
Front panel