HHB CIRCLE STUDIO MONITORS, Circle 1, Circle 3, Circle 5 Operating Instructions Manual

OPERATING
INSTRUCTIONS

CIRCLE STUDIO MONITORS

2

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

CIRCLE 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Key features (passive and active) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Key features (active only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Active Circle 5 rear panel (fig. 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Passive Circle 5 rear panel (fig. 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

CIRCLE 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Key features (passive and active) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Key features (active only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Active Circle 3 rear panel (fig. 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Passive Circle 3 rear panel (fig. 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

CIRCLE 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Key features (active) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Active Circle 1 sub-woofer rear panel (fig. 5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

LOUDSPEAKER CONNECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Circle 5 and Circle 3 active . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Circle 5 and Circle 3 passive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Circle 1 active sub-woofer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

5.1 mode - method 1 (fig. 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

5.1 mode - method 2 (fig. 7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

B mode (fig. 8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

C mode (fig. 9) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

LOUDSPEAKER POSITIONING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Stereo loudspeaker placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Suggested stereo loudspeaker placement (fig. 10) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Surround loudspeaker placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Suggested surround speaker placement (fig. 11) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

TECHNICAL DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3

CONTENTS

Circle Studio Monitors

HHB Circle studio monitors are designed and built
with HHB’s customary attention to detail. More
than 20 years’ experience and a number of unique
innovations have combined to produce studio
monitors capable of performing in the most
demanding professional environments. The Circle 5
and Circle 3, available in both active and passive
versions, together with the Circle 1 sub-woofer, are
perfect for use in a variety of stereo and surround
sound professional monitoring applications.
Extremely responsive, they deliver every
performance with power and clarity.

The HHB Circles are a true family in every sense ­both in character and appearance. Great
consistency in their design and manufacture has
resulted in a distinctive Circle sound, uniformly
matched across the entire range, enabling Circle 3s
and 5s to be freely combined in any surround setup
without detrimental effect to the reproduced sound.
Striking purple cones or grilles and a durable black
paint finish on all models further strengthen the
family resemblance.

With their high quality audio components and low
distortion filters, the HHB Circle studio monitors
are full of features. The cone on the Circle 5 is
formed from an injection moulded polymer, with
varying thickness across its diameter, for a grain­free texture and minimal cone distortion. And with
controls for master volume on the active Circle 3
and 5, along with mode switching, input sensitivity,
LF boost and phase controls on the Circle 1, all
Circle monitors are fully adaptable for every studio
or project installation.

Whether you possess a stereo pair of loudspeakers
or an entire surround sound system, the HHB Circle
studio monitors are simple to set up and simple to
use. With their many flexible options, they offer a
tailor-made solution for any monitoring application.
These operating instructions for the Circle monitors
explain the fundamentals of loudspeaker connection
and positioning, providing clear and simple
information for monitor installation - whatever your
requirements.

4

INTRODUCTION

Circle Studio Monitors

Should a HHB Circle monitor require service, it
must be taken or sent to an HHB authorised
dealer. Please retain the original packing for
possible future use, and ensure the unit is suitably
protected during transit. The manufacturer cannot
accept responsibility for damage caused during
transportation. In order to register ownership it is
essential that you complete and return the user
registration card supplied with this product. All

components used in HHB Circle studio monitors are
guaranteed against faulty materials or
workmanship for a period of one year from the date
of purchase. This warranty will become void if the
product has been misused, modified or tampered
with in any way. HHB shall not be liable for any
consequential or incidental damages due to the
failure of this product. In the unlikely event of a
product failure please contact your local dealer.

Please record the following details:

Serial number: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Date purchased: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Dealer: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The active HHB Circle loudspeakers are simple to
install, but like all electrical equipment, care must
be taken to ensure reliable, safe operation. The
following points should always be observed:

• This equipment must be earthed. In a situation
using multiple speakers the mains power should
be derived from a central set of outlets that
have a solid ground connection. Should a
problem exist with hum loops, the ground
connections on the XLR input connectors should
be disconnected, not the mains earth
connection. The mains earth connection must
NEVER be removed from these speakers.

• Ensure the speakers are the correct voltage for
the available mains supply.

• All mains wiring should be installed and checked
by a qualified electrician.

• To prevent fire or electric shock hazard do not
operate this equipment outside, or expose to
rain or moisture. Do not operate when
disassembled or if the cabinet is damaged,
exposing the internal electronics.

• When replacing the fuse in the active Circle 5,
Circle 3 and Circle 1, use only the correct rating
of fuse - a 2A slow blow type for the Circle 5A
and Circle 1A, or a 630mA slow blow type for
the Circle 3A. The fuses used must conform to
local safety regulations.

• As the performance of a new loudspeaker will
improve after the first few hours of use due to
the bedding in of the cone materials and
suspensions, it is recommended that new
speakers should be driven at a moderate level
for a few hours before critical listening is
attempted.

BEWARE - HHB Circle studio monitors are capable
of producing high sound pressure levels. Be
careful not to monitor at high volumes for long
periods as this could cause hearing damage.

5

PRECAUTIONS

Circle Studio Monitors

SERVICE

Circle Studio Monitors

Active & Passive

• Detailed, accurate and dynamic sound, both on
and off axis

• Tight, controlled low-end performance

• Accurate bass / treble driver time alignment

• 200mm (8") bass/mid driver with a unique,
injection moulded cone for increased dynamics
and minimal bass colouration

• Individually tested ferro-fluid cooled soft dome
tweeter

• Solid state, Polyswitch

®

tweeter overload

protection

• Shielding antimagnets allow use close to video
and computer monitors

• Rigid, seamless ported cabinet, finished in
durable black paint

Active Only

• 120W LF / 70W HF integral amplifier pack

• Switchable inputs; either balanced XLR or
unbalanced RCA phono

• Push-Pull amplifier design for tight, controlled
low-end performance

• Power amplifier contains anti-thump on / off
circuitry

• Extra-large toroidal transformer for added
headroom and low hum field

• Individually calibrated, low Q Sallen and Key
active filters eliminate mid-band peaks, resulting
in a sound that doesn’t tire the listener, even
after long periods

• Long life smoothing capacitors

• Massive heat sink for effective heat dissipation

6

CIRCLE 5

Midfield Monitors

As part of a complete monitoring system, HHB
Circle 5 studio monitors will deliver the clean,
highly accurate sound required. Their reliable sound
output and wide flat frequency response makes
them suitable for the highest quality audio
monitoring applications. The Circle 5s feature a
solid state Polyswitch

®

to protect the tweeter from
excessive input. Unlike other protection circuits
which limit power to the tweeter, affecting the
overall balance of the sound in a way which may not
be immediately obvious to the listener, the
Polyswitch

®

in the Circle 5 cuts all power to the
tweeter and illuminates a red warning LED. After a
couple of minutes to cool off, the switch
automatically resets, having saved the tweeter
from overload and subsequent damage.

CIRCLE 5

KEY FEATURES

7

Active Circle 5
Rear Panel

1

Figure

Passive Circle 5
Rear Panel

2

Figure

– +

MIN

MAX

0

2

10

4

6

8

Active & Passive

• High quality sound reproduction in a compact

package

• Ideal for smaller mixing applications

• Acoustically dead chassis

• Accurate bass / treble driver time alignment

• 110mm (4.5") non-resonant suspension coupling

bass/mid driver with a paper pulp cone optimised
for smooth, accurate sound reproduction with
minimum distortion

• Individually tested ferro-fluid cooled soft dome

tweeter

• Magnetically screened for use close to video /

computer monitors

• Rigid, seamless cabinet, finished in durable black

paint

Active Only

• 60W LF / 60W HF integral amplifier pack

• Switchable inputs; either balanced XLR or
unbalanced RCA phono

• Power amplifier contains anti-thump on/off
circuitry

• Anti-resonant amplifier mounting

• Low noise audio integrated circuits

• Advanced surface mount computer assembled
PCB construction

• Toroidal transformer for added headroom and low
hum field

• Individually calibrated Sallen and Key active filters

• Controlled crossover characteristics to eliminate
listening fatigue during long recording or mixing
sessions

8

CIRCLE 3

Compact Nearfield Monitors

The compact size of the HHB Circle 3 studio
monitor is ideal when space is at a premium.
Equally at home in project or commercial studios,
the Circle 3 features a 4.5" paper pulp cone,
optimised for use in the smaller cabinet. An anti
magnet screen allows the Circle 3 to be placed
next to computer or video monitors. The Circle 3
monitors can be used as part of a surround sound
system since, passive or active, they produce a
sound which is both clear and dynamic – the HHB
house sound.

CIRCLE 3

KEY FEATURES

– +

9

Active Circle 3
Rear Panel

3

Figure

Passive Circle 3
Rear Panel

4

Figure

MIN

MAX

0

2

10

4

6

8

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

10

CIRCLE 1

Powered Sub-Woofer

CIRCLE 1

KEY FEATURES

11

Active Circle 1 Sub-Woofer
Rear Panel

5

Figure

Circle 5 & Circle 3 - Passive

Choosing an amplifier to match your speakers and
application is important. The passive HHB Circle 5
requires connection to a power amplifier with a
suggested output between 50 and 200 Watts
RMS, and the Circle 3 should be powered by an
amplifier with an output of 30 to 100 Watts.
Connection is made via a pair of binding posts on
the rear of the loudspeaker. Take care to ensure
that the positive (red +) terminal on the
loudspeaker is connected to the positive
(red +) terminal on the amplifier, and that the
negative (black –) terminal on the speaker is
connected to the negative (black –) terminal on the
amplifier. Connecting one of the loudspeakers out
of phase will result in dramatic loss of low
frequency signals and an incoherent spatial image.
Always use good quality medium or heavy-duty
speaker cable, not thin ‘bell’ wire. The main
function of a speaker cable is to transfer the
maximum amount of current with the minimum
amount of distortion. It is therefore preferable to
have a cable with a wide cross-sectional area, since
this will reduce the electrical resistance. If the
cable is too thin, the resistance rises and heating
may occur. Where possible, try to use the same
length of cable for each speaker.

Circle 5 & Circle 3 – Active

Audio connection to the active HHB Circle 5 and
Circle 3 is via balanced XLR or unbalanced RCA
phono. A switch selects the desired audio input.
The active Circle 5 and 3 should be connected to a
suitable mains power supply via an IEC connector.
Power should be switched off when connecting or
disconnecting any signal to or from the
loudspeakers, or when changing the position of the
selector switch, since the loudspeakers and
internal amplifiers may be damaged. When audio
cable runs are long – about ten metres or more
(approximately thirty feet) – or there is
electromagnetic interference in the vicinity of the
cable (from a motor, for instance), it is advisable to
use balanced XLR cables so as to avoid any induced
noise. The master volume control on the active
Circle 5 and 3 acts as a sensitivity control. When
at its highest, the input is at maximum sensitivity
and the amplifiers will be fully driven by an input of
1V. The best way to set this correctly is to ensure
that the monitor output of the mixing desk or other
equipment that is driving the speakers, is set to
produce a peak output of 1V. The master volume
control also allows for balancing between
loudspeakers; ideal for use in a surround sound
environment.

Circle 1 Active Sub-Woofer

The HHB Circle 1 is an active sub-woofer,
containing built-in amplification and active
crossover circuitry, designed especially for use with
Circle 5 and Circle 3 loudspeakers in a surround
sound setup. Its flexible input and output
capabilities allow quick and simple connection to
the other loudspeakers. The HHB Circle 1
sub-woofer has three distinct modes of operation,
set by a switch on the rear panel – these modes
are ‘5.1’, ‘B’ and ‘C’. The system is designed for
decoded or discreet 5.1 reproduction but also
caters for earlier formats of surround sound or
bass enhancement in a conventional stereo system.
Using the HHB Circle 1 in ‘5.1 mode’ there are two
connection methods in a surround sound system.
With method 1, the separate sub input allows
direct connection from a dedicated line level low
frequency effects (or sub) channel on a surround
sound decoder, mixing desk, or a multitrack
recorder, Using this method, only one physical
connection is made to the sub-woofer – the other
five loudspeakers are sent their own discrete
signals directly from the mixing desk, etc.

In the second connection, method 2, all the monitor
signal outputs (normally left, centre, right, left
surround and right surround) are connected to the
inputs on the HHB Circle 1, and the outputs are
fed to the loudspeakers. This method filters the low
frequencies (below 120Hz) from the loudspeaker
feeds. The sub-woofer is always driven from the
SUB input – it receives no low frequency
information from the other five inputs. This
connection method is widely used, since by
removing the extreme low frequencies, the five

12

LOUDSPEAKER CONNECTION

Circle Studio Monitors

5.1 mode - method 1

6

Figure

full-range loudspeakers can be utilized more
efficiently. This method of signal connection makes
the most of the Circle 1’s high quality filters.

Using the HHB Circle 1 in ‘B mode’, the bass
frequencies are extracted from the left, centre and
right inputs and not from the SUB input. The left
and right monitor signals (or left, centre and right)
are connected to the XLR inputs and the bass
(below 120 Hz) is filtered from these signals,
equally mixed together and fed to the sub-woofer.
The rest of the frequency spectrum from these
inputs is output from the left and right (or left,
centre and right) XLRs as normal for connection to
Circle 3 or Circle 5 speakers. This mode allows
optimum flexibility with both stereo and LCR source
formats.

With the HHB Circle 1 in ‘C mode’, the bass
frequencies are filtered from the left, centre and
right inputs and summed together with the signal
from the SUB input (either XLR or RCA phono).
This method of connection ensures that any
dedicated sub bass mix is always reproduced by
the Circle 1.

The three controls on the HHB Circle 1 allow
simple configuration for each particular surround
setup. An input sensitivity level adjusts the volume
of the sub woofer, without affecting any of the
other signals that may be passing through the
filter stages of the unit. The bass boost control
provides approximately 10dB of boost in a half
octave centred at 33Hz. The function of this is to
compensate for the frequency response of the
human ear when listening at low levels. The boost
control should be normally be set near minimum
when listening at mid to high levels, but the boost
level may be increased as the listening level is
reduced. Please note that the HHB Circle 1 is not
designed to be used at full boost and very high
level. Some user adjustment is required to obtain
the optimum balance between the preferred sound
and power handling / power capacity of the
system. The phase control is provided to enable
smooth integration of the Circle 1 with other
loudspeakers in the surround system; this control
alters the phase of the sub-woofer signal through
180°, enabling the sub-woofer to blend with the
other loudspeakers in the system, whatever your
monitoring requirements. The phase control should
be adjusted to obtain the best, smoothest balance
between the deep, mid and upper bass along with
the mid and high frequencies in the Circle surround
system, with the entire system installed and in the
correct positions.

13

B mode

8

Figure

5.1 mode - method 2

7

Figure

C mode

9

Figure

Whether you have a stereo or surround sound
system, correct positioning of loudspeakers in the
room is essential, as this will greatly affect the
accuracy of the reproduced sound. Speakers
radiate sound from all directions and therefore
placing them against walls or on the floor is not
advisable. HHB Circle 5 and Circle 3 monitors are
optimised for use under free-field conditions - so for
the best results, consider the following points
when setting up your loudspeaker system.

• The Circle 5 and Circle 3 loudspeakers should be
placed upright on stands, away from boundaries
to reduce reflections. Do not place them on their
sides, as the response at the crossover
frequency will be less accurate.

• Both speakers should be the same distance from
the listening position.

• The Circle 5 and Circle 3 loudspeakers should be
slightly angled in towards each other, so as to
point towards the listening position, and placed
at a height where the listener’s ears are level
with the tweeters.

• Ideally, the two loudspeakers and the listener
should sit at the corners of a triangle, where all
sides are of equal length:

• The listener should not sit too close to the
speakers, (i.e., within this imaginary triangle),
since the important centre image (sweet spot)
can be greatly affected when listening in this
position.

• The loudspeakers should be placed away from
corners and walls - more than one metre away
(approximately three feet) is ideal - since there
may be unwanted interference patterns caused
by the reflections of the signal from the walls,
which will colour the low and mid frequencies,
giving the impression of extreme bass warmth
and unnatural midrange.

• At these low frequencies, the sound from the
loudspeakers radiates in all directions, and
reflects off any hard surfaces to combine with
the direct sound. At higher frequencies, sound
from the loudspeakers is more directional,
causing less of a problem with interference.

• Avoid placing the Circle 5 or Circle 3 studio
monitors on top of a mixing console, since this
will adversely affect the frequency response.
Some of the sound output will reflect off the
surface of the console, interfering with the direct
sound from the loudspeakers. Instead, position
the speakers on stands slightly behind and above
the console.

L

R

Loudspeakers

Listener

Suggested stereo
loudspeaker placement

14

LOUDSPEAKER POSITIONING

Circle Studio Monitors

STEREO

LOUDSPEAKER PLACEMENT

10

Figure

• The loudspeaker arrangement for surround sound
monitoring may comprise three front channels
and two surround channels, each placed upright
on stands an equal distance from the listening
position.

• A sub-woofer is often used to improve the
system’s low frequency response. A typical setup
may consist of five HHB Circle 5 loudspeakers
with a Circle 1 sub-woofer.

• Ensure that all five loudspeakers are positioned
at the same height - ideally, this will be so that
the tweeters are level with the listener’s ears.

• Due to the consistent sound quality of the HHB
Circles, it is possible to mix Circle 5s and Circle
3s in the same surround setup. The front three
speakers, left, centre and right, may be Circle
5s, with a pair of Circle 3s used for left surround
and right surround.

• Widely used in films and pop music, extreme low
frequency effects, as produced by the HHB Circle
1, are often felt rather than actually heard.

• Since the Circle 1 sub-woofer will only produce
low frequencies, often with a wavelength of up to
ten metres, it is often hard to localise, enabling
the speaker to be placed on the floor or slightly
to one side of the listening position without
altering the overall spatial image.

• Distance from the listening position to each of
the loudspeakers should always be the same. If
the listener is at the centre point of an imaginary
circle, the speakers should all lie on the circle’s
circumference.

• There are no hard and fast rules as to the exact
placing of the left and right surround
loudspeakers - this circular diagram is merely
intended as a guide. In fact, many recording and
mixing studios have their surround loudspeakers
mounted on moveable trolleys, enabling each
client to place them in their preferred position.

15

SURROUND

LOUDSPEAKER PLACEMENT

Suggested surround
loudspeaker placement

C

L R

SUB

RSLS

11

Figure

30°

130° - 150°

Circle 3 Passive

Transducer System . . . . . . . . . . . . . . . . . . . . . . . . . . 2 way monitor loudspeaker.

Drive Units . . . . . . . . . . . . . . . . . . . . . . . . LF: Custom 110mm (4.5") NRSC cone,

25mm (1") voice coil, high linearity low-loss suspension

rigid self-sealing polymer chassis and shielding antimagnet.

HF: 25mm (1") ferro-fluid cooled soft dome, high efficiency Neodymium magnet,

highly focused magnetic field 25mm (1") aluminium voice coil.

Frequency Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70Hz - 20kHz +/-3dB.

Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83dB 1W/1m.

Suggested Amplifier Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 - 100W.

Impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Ohms nominal.

Power Handling (Programme) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60W.

Crossover . . . . . . . . . . . . . . . . . . . . . . Pro-grade components on fibreglass PCB,

critically damped, 3.5kHz crossover.

Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Binding posts.

Dimensions (HxWxD) . . . . . . . . 270mm x 175mm x 197mm / 10.6" x 6.9" x 7.8".

Weight . . . . . . . 3.7kg (8.1lbs) each (net), 8.4kg (18.5lbs) packed in pairs (gross).

Finish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Durable black paint finish.

Circle 3 Active

As passive, but with the addition of an internal power amplifier.

Sensitivity For Full Output with Input sensitivity control at max: . . . . . . . . 1V RMS.

Power (Programme) . . . . . . . . . . . . . . . . . . . . . . . . . . 60W Bass, 30W Tweeter.

Active Crossover . . . . . . . . . . . . . . . . . . . . . . . . . . . . Crossover point at 3.5kHz.

Sallen & Key active filters for LF and HF.

Advanced design using ultra high precision components.

Low noise audio semiconductors and 1% precision

resistors throughout audio circuitry.

Power Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Anti thump on/off circuitry.

Regulated low noise and distortion power supply.

Connectors . . . . . . . . . . . . . . . . . . . Slide Switchable XLR (female) or RCA phono.

Main Input Voltage . . . . . . . . . . . . . . . . . . . . . European model: 220-240V, 50Hz.

U.S. / Canadian model: 110-120V, 60Hz.

Dimensions (HxWxD) . . . . . . . . 270mm x 175mm x 220mm / 10.6" x 6.9" x 8.7".

Weight . . . . . 5.0kg (11.0lbs) each (net), 11.0kg (24.2lbs) packed in pairs (gross).

Both active and passive Circle 3s are packaged in pairs. Single units can also be ordered.

Circle 5 Passive

Transducer System . . . . . . . . . . . . . . . . . . . . Ported 2 way monitor loudspeaker.

Drive Units . . . . . . . . . . . . . . . . . . . . . . . . LF: Custom 200mm (8") polymer cone,

high compliance long throw rubber surround.

25mm (1") high temperature aluminium voice coil and antimagnet.

HF: Custom 28mm (1.1") ferro-fluid cooled soft dome

with rear damping chamber. 28mm (1.1") high temperature

aluminium voice coil and antimagnet.

Frequency Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48Hz - 20kHz, +/- 3dB.

Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87dB 1W/1m.

Suggested Amplifier Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 - 200W.

Impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Ohms nominal.

Power Handling (Programme) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120W.

Crossover . . . . . . . . . . . . . . . . . . . . . . Pro-grade components on fibreglass PCB,

critically damped, 2.6kHz crossover.

Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Binding posts.

Dimensions (HxWxD) . . . . . . 420mm x 255mm x 300mm / 16.5" x 10.0" x 11.8".

Weight . . . . 10.0kg (22.0lbs) each (net), 20.4kg (44.9lbs) packed in pairs (gross).

Finish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Durable black paint finish.

Circle 5 Active

As passive, but with the addition of an internal power amplifier.

Sensitivity For Full Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1V RMS.

Power (Programme) . . . . . . . . . . . . . . . . . . . . . . . . . 140W Bass, 70W Tweeter.

Active Crossover . . . . . Crossover point at 2.6kHz. Sallen & Key active filters for LF

and HF. Advanced design using ultra high precision components.

Low noise audio ICs and 1% precision resistors used throughout.

Power Amplifier . . . . . . . . . . . LF unit driven by twin power ICs in Push-Pull mode.

HF unit driven by a single IC. Anti thump on/off circuitry.

Regulated low noise, low distortion power supply with long life

capacitors, guaranteeing full power over a long service life.

Polyswitch

®

tweeter overload protection with LED indicator.

Every module calibrated against reference for perfect stereo imaging.

Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Switchable XLR / RCA phono.

Main Input Voltage . . . . . . . . . . . . . . . . . . . . . European model: 220-240V, 50Hz.

U.S. / Canadian model: 110-120V, 60Hz.

Dimensions (HxWxD) . . . . . . 420mm x 255mm x 300mm / 16.5" x 10.0" x 11.8".

Weight . . . . 12.6kg (27.7lbs) each (net), 25.6kg (56.3lbs) packed in pairs (gross).

Both active and passive Circle 5s are packaged in pairs. Single units can also be ordered.

Circle 1 Powered Sub-Woofer

Transducer System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Active bandpass twin chamber reflex sub-woofer.

Drive Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LF: 300mm (12") double-magnet, contour-optimised cone with

high compliance long throw rubber surround rigid magnesium chassis.

Low moving mass for fast transient attack. Air-cooled magnet system. 40mm (1.6") diameter aluminium voice coil.

Frequency Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Hz - 120Hz,+/- 3dB in free space.

Sensitivity For Full Output, input sensitivity at max, sub woofer (effects) channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1V RMS.

Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Input sensitivity, LF boost, phase.

Active Crossover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 main channels pass through Sallen & Key filters, crossover point at 120Hz, and

are available in XLR outputs. Advanced design using ultra high precision components.

Low noise audio semiconductors and 1% precision resistors used throughout audio circuitry.

Power Amplifier . . . . . . . . . . . . . . . . . . . . . 160W min (programme). Anti thump on/off circuitry. Regulated low noise, low distortion power supply with long life capacitors,

guaranteeing full power over a long service life.

Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XLR inputs (female): L, C, R, L rear, R rear. XLR (female) and RCA phono: Sub-woofer (effects channel)

XLR outputs (male) L, C, R, L rear, R rear,

all band limited to 120Hz to connect to ‘satellite’ speakers.

Main Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .European model: 220-240V, 50Hz. U.S. / Canadian model: 110-120V, 60Hz.

Dimensions (HxWxD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465mm x 414mm x 414mm / 18.3" x 16.3" x 16.3".

Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.5kg (47.3lbs) each (net), 27.0kg (59.4lbs) packed in singles (gross).

Finish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Durable black paint finish with perforated purple grille.

Dealer Stamp

www.hhb.co.uk

HHB Communications Ltd · 73-75 Scrubs Lane, London NW10 6QU, UK

Tel: [phone] · Fax: [phone] · E-Mail: [e-mail]
HHB Communications USA LLC · 1410 Centinela Avenue, Los Angeles, CA 90025-2501, USA

Tel: [phone] · Fax: [phone] · E-Mail: [e-mail]
HHB Communications Canada Ltd · 260 King Street East, Toronto, Ontario M5A 4L5, Canada

Tel: [phone] · Fax: [phone] · E-Mail: [e-mail]

TECHNICAL DATA

Circle Studio Monitors