HHB comm CIRCLE STUDIO MONITORS - Manual (Page 10)

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). In C
mode, low frequency information is filtered from
the left, centre and right input signals and added
to the sub-woofer signal, ensuring optimum low
frequency performance. 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.
• 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 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
(B mode) or summed (C mode) to the sub-woofer
input within the Circle 1
• Balanced XLR and unbalanced RCA phono
sub-woofer input
• 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
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CIRCLE 1
Powered Sub-Woofer
CIRCLE 1
KEY FEATURES
CIRCLEOP.QXD 5/4/00 5:03 pm Page 10