Downward
firing 10.5" long throw rigid aluminium driver.
150w
True RMS amp panel with digital display.
XLR &
RCA low level connectors.
High & Low level simultaneous connection capable.
Infinitely
variable frequency contour.
Produces
a superb low 10Hz.
Box in box rigid, ported cabinet.
Introducing
an industry first, the awesome Reference I MkII
active subwoofer from MJ Acoustics. Capable
of producing a super low 10Hz using our latest
D.A.M.P technology
with dual digital displays
and twin crossovers - taking the guess work
out of setting up your subwoofer.
Amplifier
Resulting from years of development, the 150Wrms
DC-coupled BI-Polar amplifier provides the engine
to power the perfectly matched 10” ultra long
throw aluminium woofer. The power supply has been
designed to awesome requirements. We fit a 150va
Double Insulated Toroidal transformer which has
been designed specifically for this audio application.
The rectifier used is a 10 Amp 60v version; it,
of course, never sees 10 amps or 60 volts as this
would equate to 600W’s but it is just an example
of how over engineered this amplifier is, and substantiates
why, when deep transients are required, the amplifier
has enormous reserves of power to accommodate with
utter ease even the deepest of explosions. To aid
this the capacitors used are the large bucket type
with a ripple current of 10 Amps each and selected
because of their high temperature and minimal loss
characteristics. The transistors used are the Metal
Oxide Semiconductor Bi-Polar type and specifically
designed for audio applications.
Crossover
The “Reference I MkII” has the ultimate
in sophisticated crossover circuits. Twin Digitally
Accurate MicroProcessor controlled crossover circuits
(D.A.M.P.), incorporate a digital display so that
the upper response limit can be set in musically
accurate variable increments between 30hz and
120hz. A "straight-through" LFE bypass
facility is activated at one end of the Lo level
controls travel which allows the input signal
to bypass the filter circuit. The LFE bypass is
used where an already filtered signal is offered
to the low level input sockets. An example of
this would be a sub output from a dedicated control
pre-amplifier such as found in a Home Cinema system.
There are separate crossover and
gain controls for high and low level inputs, a
"straight-through" LFE bypass and an
audibly transparent, "Automatic Speaker Protection"
(A.S.P.) circuit which monitors the output stages
for clipping and limits the cone movement if the
amplifier is being over-driven. Professional Neutrik
Speakon connectors are standard for the “Reference
I MkII’s” stereo high level input.
An approved touch proof design is employed to
cater for potentially high voltages that can be
connected to it complete the high level input
socketry. The “Reference I MkII” also
offers a balanced low-level XLR input and output
for use with professional mixing desks and suitably
equipped domestic systems. Additionally, gold
plated RCA connectors are offered to cater for
input and output. There is a relay in the signal
output of the amplifier which waits for 2-3 seconds
before it connects the loudspeaker. This allows
the power supply to settle and prevents a loud
thump that would occur without it.
Speaker
Using a die-cast solid aluminium chassis of monstrous
proportions creates the rigidity that is so important
in sub-bass speaker requirements. Any distortion
of the chassis under extreme load will detract from
the goal of pure sound wave formation. As we all
know the creation of sound waves comes directly
from the movement of the cone surface through the
air. The longer the movement of the cone, termed
as its excursion, the more air it moves and up goes
the sound pressure level. We like to think of our
10" driver as the best of all worlds. It has
agility, rigidity and declarative damping to enable
the cone to move with lightning speed back and forth
through the air. Incorporating an optimized linear
motor with progressive suspension to avoid bottoming
and allow maximum linear excursion. The result is
extremely low total harmonic distortion (THD). The
voice coil is aluminium and bonded to the aluminium
cone to form a one piece structure which is much
stiffer than could be achieved from a paper version.
The result is a piston like action adding to the
accuracy of the wave formation. Better heat dissipation
and further reduced THD is achieved as a result
of the rigid one piece aluminium cone structure.
The massive rubber cone surround together with the
semi-rigid lower damping apron serve to bring the
cone to an almost instantaneous return to its resting
place between transients. Truly, the muscle of the
system and the working end of this bass producer.
D.A.M.P.
D.A.M.P. (Digitally Accurate MicroProcessor)
This Digitally Accurate Microprocessor controlled
crossover circuit (DAMP)
The "Reference I MkII" has the ultimate
in sophisticated crossover circuits. A Digitally
Accurate Microprocessor controlled crossover circuit
(DAMP), incorporates dual digital displays so that
the upper response limit can be set in musically
accurate variable increments between 30hz and 120hz
for both high and low level inputs. A "straight-through"
LFE bypass facility is activated at one end of the
low level control travel which allows the input
signal to bypass the filter circuit.
A.S.P.
A.S.P. (Automatic Speaker Protection)
This circuit monitors the output and the input of
the amplifier. As the output reaches close to the
limit of the power supply rails the input is instantly
reduced to prevent the amplifier from clipping.
The dynamic range of the amplifier is not compromised
as the circuit has been set to activate at a point
beyond the full dynamic range before protection
is activated.
