d&b audiotechnik A1 Mainframe F-Series, Руководство пользователя

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Signal
waveform
CF P
out
[W]
P
in
[W]
P
loss
[W]
Square wave 1 2150 2900 750
Sine wave 1,4 1400 2130 730
Pink noise, com-
pressed music
3,5 200 500 300
Music with me-
dium dynamic
range
5 100 300 200
Speech, music
with wide dyna-
mic range
8 40 200 160
CF : Crest factor
P
out
: Maximum average outputpo-
wer (sum of both channels)
P
in
: Power input
P
loss
: Power loss
A1 Power balance
Average power consumption and loss of A1 as a factor of
output power with pink noise signal
(load impedance 4 / 8 ohms, both channels driven, sum of
output power of both channels)
Average power consumption and loss of A1 as a factor of
output power with sine wave signal
(load impedance 4 / 8 ohms, both channels driven, sum of
output power of both channels)
2000
1000
100
50
1 10 100 1000 2000
power [W]
average output power [W]
loss
consumption
2000
1000
100
50
1 10 100 1000 2000
power [W]
average output power [W]
loss
consumption
2-8 A1 User Manual
2.5. Power consumption and power loss
The power required from the mains supply and the waste heat
produced by the amplifiers power loss are variable figures
depending on the load impedance and the signal levels and
characteristics (e.g. speech, music).
In practice, the theoretical peak power consumption of a system
will only be sustained for a short period of time. Basing mains
current and air conditioning plant requirements on the peak power
consumption of the sound system would result in a generously
over-specified installation. The key factor in power consumption
calculations is the crest factor of the music signal or speech signal -
the ratio of peak to sustainable RMS voltage of the signal.
The table on the right gives power figures for various types of
signal waveforms. The figures were measured on a A1 mainframe
driving a 4 and 8 ohms load (LO and HI channel) to the clipping
point of both mainframe power amplifiers.
Power input and thermal power loss as a function of average
output power for sine wave and pink noise signal waveforms can
also be derived from the two graphs shown below (Note that pink
noise signal reaches the clipping point of the amplifiers at approx.
200 W average output power).