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The Circle 1 active sub-woofer is the perfect loudspeaker to
complement the Circle 5 and Circle 3 in surround sound
applications. Faithfully reproducing all the low frequency
effects found in films and music, the HHB Circle 1 greatly
improves the bandwidth of loudspeaker systems. With its
built-in active crossover, any combination of up to five
full-range loudspeakers, depending on the application, may
be connected to the Circle 1, allowing its on-board filters to
remove extreme low frequency content from the other
signals, preventing their overload whilst attempting to
reproduce these high energy frequencies. With this
arrangement, no additional filtering is needed. Dedicated
sub-woofer signals may be sent directly from a mixing
console or multitrack recorder to the Circle 1 (5.1 mode), or
the internal circuitry can extract the low frequency
information from the left, centre and right input signals (B
mode). The Circle 1’s paper pulp 12" LF driver is mounted at
the top of the cabinet, displacing air out of the acoustically
optimised front port.
Key Features - Circle 1
• Designed for use as an integral part of any surround sound
monitoring system
• Increases the bandwidth of a loudspeaker system down
to 33Hz
• Exceptionally low colouration and distortion
• 300mm (12") paper pulp bass/mid driver
• Low moving mass for fine transient response
characteristics
• Air-cooled magnet system
• Very large voice coil and long throw suspension
• Flexible configuration possibilities, with either direct input
of sub-woofer signal (5.1 mode) or low frequency
information extracted from the left, centre and right signal
paths, and fed internally to the sub-woofer input within the
Circle 1 (B mode)
• Built-in 5-channel Sallen and Key active filters remove the
need for external filtering
• Low noise, low distortion power supply with long life
smoothing capacitors
• Variable phase control allows blending with existing
speaker / room combinations
• Variable bass boost control achieves optimum bass
balance across a range of differing listening levels (lower
listening levels require bass boost according to
psychoacoustic theory)
• Input sensitivity control allows matching of sound balance
across the whole surround monitor system
• Built-in temperature overload sensor
• Rigid, ported cabinet, finished in durable black paint
• Distinctive purple grille
Circle 1
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