Neumann.Berlin KH 420, Руководство по эксплуатации

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KH 420 |
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Example
Video delay compensation on loudspeaker A: 2 x 40 ms/frame
Desired time-of-flight compensation for loudspeaker A: 0.4 ms
Time-of-flight compensation: 80.4 ms
This delay value can be made with these switch settings: 3 x 25.6 ms, 2 x 1.6 ms, 4 x 0.1 ms.
The latency of the analog-to-digital and digital-to-analog converters should be
taken into account when using the DELAY rotary switches
M
for time-of-flight com-
pensation. For the digital-to-analog conversion (input signal via digital connector),
the latency is dependent on the sample rate (values can be seen in the Specifica-
tions table on page 24). The analog-to-digital-to-analog conversion (input sig-
nal via analog connector) is fixed at 0.54 ms.
For time-of-flight compensation delay, calculate the desired delay value then sub-
tract the appropriate latency depending on the input signal and sample rate, and
then set the needed additional delay using the delay switches on the back panel.
Example:
Distance compensation for 1 m: 1 m / 344 m/s = 2.91 ms: 2.91 ms
Digital input signal, sample rate: 48 kHz, latency:
0.85 ms
2.06 ms
Delay settings:
0 x 25.6 ms, 1 x 1.6 ms, 5 x 0.1 ms
(equals 2.1 ms, which is the nearest value)
For video delay compensation, converter latency can be ignored as it is insignifi-
cant compared to long video signal delays.
To help with choosing a delay setting there is a set of lookup tables at the end of
this operating manual. Also Neumann has made a delay calculator which is availa-
ble at www.neumann.com.
DIM 1 DIM 1 DIM 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M I I I I I I I I I I I I I I I I I I D D D D D D D D D D D D D D D D D D D D D D D D D D D
Activating ground lift
If there is humming or buzzing noise coming from the loudspeaker, first search for the cause
of the noise:
X
Disconnect all input and output signal cables from the loudspeaker.
If the noise goes away, it is probably coming from the audio source or source cabling.
It might be possible to eliminate the noise by disconnecting the ground from the input signals
(activating ground lift).
To activate ground lift:
X
Reconnect the signal cables and set the GROUND switch
G
to “LIFT”.
This internally disconnects pin 1 of the ANALOG INPUT socket (XLR)
H
from the loudspeaker’s
chassis ground (see diagram “Pin assignment of the XLR socket” on page 14).
For safety reasons, the electronics chassis ground is always connected to the mains
power earth pin.
EN