2.3 Operation
NOTICE!
Only operate d&b loudspeakers with a correctly configured d&b
amplifier, otherwise there is a risk of damaging the loudspeaker
components and the system performance can not be achieved.
Applicable d&b amplifiers:
D6|D20|D80|10D|30D|40D
Amplifier output mode(s): Dual Channel or Mix TOP/SUB
Application
Setup
Cabinets per
amplifier
channel
44S
44S
4
2.3.1 Controller settings
For acoustic adjustment the functions CUT, HFA and CPL can be
selected.
CUT mode
Set to CUT, the cabinet low frequency level is reduced. The cabinet
is now configured for use with applicable, actively driven d&b
subwoofers.
HFA mode
In HFA mode (High Frequency Attenuation), the HF response of the
system is rolled off. HFA provides a natural, balanced frequency
response when a unit is placed close to listeners in near field or
delay use.
High Frequency Attenuation begins gradually at 1 kHz, dropping
by approximately 3 dB at 10 kHz. This roll off mimics the decline
in frequency response experienced when listening to a system from
a distance in a typically reverberant room or auditorium.
CPL function
The CPL (Coupling) function compensates for the different acoustic
properties depending on whether the loudspeaker is freely
positioned or flush-mounted.
At attenuation values of up to –5, CPL begins gradually around
1 kHz and reaches the maximum attenuation below 200 Hz. At
higher values of up to –9, the filter corner frequency gradually
shifts to higher frequencies while an attenuation of 5 dB is
maintained.
Positive CPL values create an adjustable low frequency boost (0 to
+5 dB) at around 90 Hz and can be set when the system is used in
full range mode without subwoofers.
-5
0
5
10
-10
-15
-20
-25
-30
20
100
1k
10k
20k
Frequency response correction in HFA mode*
*schematic diagram
Frequency response correction of the CPL function*
*schematic diagram
d&b 44S Manual 1.1 en
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