AKG CEQ1/1, Руководство пользователя

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CEQ1/1 und CEQ1/1BB
1. Introduction
The CEQ1/1 is a 27 band, constant-Q, automatic equalizers. The CEQ1/1 has a 2 line LCD screen
for user interface, while the EQ2 is a blank faced unit. Both of the units have the capability to inject
pink noise into a sound system, and to measure and adjust the system equalization to a user speci­
fied target curve. In addition, a dynamic pop suppressor minimizes breath pops. The CEQ1/1 has
an RS-232 port for remote set-up or control by a computer or other RS-232 compatible controller.
The CEQ1/1 uses a straightforward analog signal path to provide excellent audio performance. 27
bands of constant-Q equalization allows systems to be accurately equalized. The constant-Q
topology means less interaction between adjacent EQ bands, which in turn means less “tweaking”
of the EQ settings to achieve the desired EQ curve. The CEQ1/1 have a programmable pink noise
generator and a programmable 1/3 octave measurement filter. These provide the capability to
stimulate a room with pink noise, and measure its response. A sophisticated automatic equaliza­
tion algorithm is used to equalize the room, typically to /-2dB of a user selected target
curve. This process takes just over one minute.
A fixed frequency, switchable low cut filter combines with Dynamic Pop Suppression (DPS) circuitry
to give precise control over system low frequency performance. The DPS system is a dynamic
high-pass filter, which reacts only to low frequency transients. Breath pops or bass boost from
speaking too close to a directional microphone are both significantly reduced. Since the filter is
dynamic, it has no effect on the normal frequency response of the system.
Figure 1. shows the block diagram of the CEQ1/1. Balanced inputs are available for both the line
level input to the EQ and the reference microphone. Note that either input may be used as the
source for the AutoEQ
TM
process. The signal path includes the switchable low cut filter, the 27 band
equalizer, the DPS system, and a balanced output driver. The output source may be switched
between the normal signal path and the pink noise generator (used for the AutoEQ
TM
process).
The programmable 1/3 octave bandpass filter and log converter allows post-EQ system response
to be measured as part of the AutoEQ
TM
process.
An RS-232 port is available to allow many of the functions of the CEQ1/1 to be controlled either by
a computer or a dedicated control system (such as the AMX or Crestron systems).
THRU OUT +
THRU OUT –
GND
EQ IN +
EQ IN –
GND
REF MIC IN +
REF MIC IN –
GND
SERIAL
DATA LINK
RS-232 OUT
RS-232 IN
SERIAL
EEPROM
16dB GAIN
+15V PHANTOM
EQ OUT +
EQ OUT –
TO A/D
TO A/D
FROM POP SUPPRESSOR
FROM BANDPASS FILTER
EQ SOURCE
REF MIC SOURCE
FILTER
IN/OUT
NOISE OUT
EQ OUT
27 BAND 1/3 OCTAVE
CONSTANT Q
EQUALIZER
PINK NOISE
GENERATOR
PROGRAMMABLE
BANDBASS
FILTER AND LOG
CONVERTER
DYNAMIC POP
SUPPRESSION
FILTER
68HC705
uC
LOWCUT
FILTER
A/D
CONVERTER
(EQ1 ONLY)
LCD DISPLAY
SAVE
SELECT
DOWN
UP
Figure 1 - CEQ1/1 Block Diagram
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