Behringer ULTRA-CURVE PRO DSP8024, Руководство пользователя

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Fig. 3.7: Several ULTRA-CURVE PROs in an “advanced” Delay application
The same applies to ULTRA-CURVE PRO No. 4, the Delay time in this case allowing for the time difference
between loudspeaker groups 2 and 3. This method of digitally “chaining” the ULTRA-CURVE PRO through
AES/EBU can only work when using the same type of loudspeakers, or at least when a minimum of equaliza-
tion will be carried out by the ULTRA-CURVE PRO placed after the first one in the chain. The reason for this is
that despite the maintenance of signal quality afforded by digital signal processing and transfer, by linking
several digital filters in series with each other, the quantization noise from each device will be summed, which
can result in it becoming an audible noise problem.
This noise will not arise when a series of DELAYs are linked together as no processing takes place, instead
the signal is merely stored briefly in each unit. If equalizer settings are required which differ substantially from
each other, it is recommended to link the units in parallel to each other, either via analog, or using an AES/EBU
signal distributor.
4. TECHNICAL BACKGROUND
4.1 Audio dynamics
By employing current modern analog technology it is possible to manufacture audio equipment with a dynamic
range of up to 130 dB. In contrast to analog techniques, the dynamic range of digital equipment is approxi-
mately 25 dB less. With conventional record and tape recorder technology, as well as broadcasting, this value
is further reduced. Generally, dynamic restrictions are due to noisy storage in transmission media and also the
maximum headroom of these systems.
4.1.1 Noise as a physical phenomenon
All electrical components produce a certain level of inherent noise. Current flowing through a conductor leads
to uncontrolled random electron movements. For statistical reasons, this produces frequencies within the
whole audio spectrum. If these currents are highly amplified, the result will be perceived as noise. Since all
frequencies are equally affected, we term this white noise. It is fairly obvious that electronics cannot function
without components. Even if special low-noise components are used, a certain degree of basic noise cannot
be avoided.
This effect is similar when replaying a tape. The non-directional magnetic particles passing the replay head can
also cause uncontrolled currents and voltages. The resulting sound of the various frequencies is heard as
noise. Even the best possible tape biasing can “only“ provide signal-to-noise ratios of about 70 dB, which is not
acceptable today since the demands of listeners have increased. Due to the laws of physics, improving the
design of the magnetic carrier is impossible using conventional means.
4. TECHNICAL BACKGROUND
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