Linn AKTIV Crossover Owner's Manual page 9

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NTRODUCTION
amplifiers and loudspeakers in your hi-fi system to work together in an
ideal way. The active filters give greater accuracy and lower distortion
than conventional passive crossovers. The power amplifier is connected
directly to the drive units so that none of the amplifier's power is lost. The
drive units are more controlled, give lower distortion and higher efficiency.
A good active system gives a sound which cannot be achieved by any other
means. You just have to listen to it.
A crossover is a filter which splits the complete music signal into two or more
frequency bands before it is fed to the drive units in the loudspeakers. This
is done because no single drive unit can operate over the entire musical
range. With a passive crossover, this filtering is done after the power
amplifier, so only one power amplifier is required. With an active crossover,
the filtering is done before the power-amplifier, so it becomes possible to
dedicate a power amplifier to each drive unit. This is ideal for both the
amplifier and the drive unit.
The problem with passive crossovers is that you can only ever get out of them
less than you put in; they work essentially by absorbing signal, so the more
accurate you try to make them, the less efficient they become and the more
amplifier power is consumed. In an active crossover, electronic amplifiers
which have gain are used so there is no such trade-off between accuracy and
efficiency. This allows highly sophisticated response correction for the
loudspeaker to be implemented.
These modules are designed to be fitted inside Linn power amplifiers. This
approach has many advantages. Linn manufacture both the amplifiers and
the speakers involved, so the modules can be optimised for a well understood
environment. Sound quality is improved by reducing the number of cables and
connectors, which also makes the installation a lot neater, and expense is
reduced because there is no need for a separate case and power supply. The
modules are built using the latest surface-mount technology, which keeps
the circuitry very compact, minimises connections and improves immunity to
interference. As with all other Linn Electronics, there are no mechanical
controls in the signal path - all adjustments are done with solid state
switches, which cannot age or add distortion.
The Linn AKTIV Crossover modules enable the filtering,
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