Introduction - Lehmannaudio Black Cube Linear Pro Bedienungsanleitung

Black Cube Linear Pro
Dear customer,
Congratulations for buying the Lehmannaudio
Black Cube Linear Pro. You will be rewarded
with the best possible sound from your head-
phones. The Black Cube Linear Pro is carefully
manufactured in small quantities. It is supposed
to be connected to professional audio gear.
You can use nearly all dynamic headphones on
the market. Carefully selected components and
a highly sophisticated circuit design guarantee
a very high level of audio reproduction.
Why headphones?
Whenusing headphones you can reach a very
high level of sound reproduction at a fraction
of the price you would have to spend for a
regular monitoring setup with high quality
loudspeakers. Detail resolution and dynamics
of even the best loudspeakers can be achieved
with headphones. Furthermore, there are no
problems to control the sound in a noisy or non
ideal ambience.
Comparison of headphones to loudspeakers?
There is a number of parallels between regular
(dynamic) headphones and loudspeakers. Tech-
nically they are complex loads for the amplifiers
driving them and should therefore be used
with stable outputs. There are headphones with
higher impedance that need a higher signal
voltage and low impedance types which need
more current. For optimal sonic results take
care to match headphones and amplifier. Just
connecting any headphone to a given head-
phone output without considering the head-
phone's electrical characteristics won't work.
Impedances of dynamic headphones can vary
from 0 Ohms to 600 Ohms. Transferred to
loudspeakers this would result in impedances
from  Ohms to 80 Ohms. The same signal am-
plitude results in a power consumption
difference of factor 0!
Lehmannaudio
Vorwort
Loudspeakers and headphones are made in
a dazzling variety. Besides their impedance
headphones and loudspeakers can have a
very different effectivity. Which means that
the electrical signal is converted more or less
effective to acoustic energy. When compar-
ing loudspeakers the dimension used is the
sound pressure level (SPL) reached at a given
power of 1W (at 1m distance). There is a similar
parameter for the effectivity of headphones
except for the fact that the standard power is
1mW (=1/1000W) The figure is given as dB/mW
which means the resulting sound pressure level
at 1mW.
If the power is doubled then the resulting
sound pressure level is dB higher. When this
is calculated the other way round it means that
only half of the power is needed when using a
headphone with dB more effectivity to reach
the same sound pressure level. The dB formula
is valid for headphones and loudspeakers.
From the given effectivity the power needed
for a certain sound pressure level can be
derived. The power for the same sound pres-
sure level can differ up to a factor of 500 for
different headphones on the market. In the end
what counts when selecting a headphone or
a headphone amplifier is the desired volume
than can be reached without distortion. At least
equally important is to avoid damage for the
headphone and – most important – to avoid
damage for your hearing. The maximum power
rating is a figure that can be found in the data
sheet of the headphone. From this power rating
the maximum voltage can be derived. If the
voltage will be higher then the voice coils of
the headphones will be destroyed. Today most
headphones allow hearing levels well above a
secure level for the listener. This means that a
standard pair of cans might survive extremely
high levels without any degradation of long
term performance but the hearing of the lis-
tener might be seriously damaged.
The chart on page  shows the recommended
volume and listening time.
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