Page 6
Features
Using a die-pressed steel chassis of significant proportions creates the rigidity that is so
important in sub-bass speaker designs. 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 decelerative
damping to enable the cone to move with lightning speed back and forth through the air. The
heavy duty 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. The weight of this
unit says it all when referring to construction rigidity. It weighs 7Kg representing over half the
total of 11.5Kg. Truly, the muscle of the system and the working end of this bass producer.
Speaker
MJ Acoustics Pro 50Mk2 User’s Manual
Connectivity
You can connect an unbalanced RCA input direct from a mixing desk
or line level pre-amplifier with or without a sub output . Either mono or
stereo input detail may be used. When connecting from an A/V
amplifier use the subwoofer LFE output.
For connection directly to the parallel output from the speakers of the
main audio system in order for the filter circuit to extract the
information required to output the required bass frequencies. The
maximum amplifier that can be connected is 250watts and only when
connected in parallel with speakers designed to handle this power.
Do not connect direct to an amplifier unless in parallel with a speaker.
Damage may well occur if you do, to the input circuit of the filter stage.
The LED on the rear panel shows that the unit is powered and the
amplifier is ready for use. Please note that the LED will remain lit for a
short while following switch-off whilst the power is dissipated from the
internal power supply. It is always good practice to remember to turn all
input gain controls down when powering down The unit’s fuse is located
below the mains input connector. The fuse should only be replaced,
when required, with one of the same type and rating as installed. (2
amps).
10/10/2006 (Pro – 50Mk2)
NOTE.
An Optional interface box is required if you connect to a Digital or BTL (Bridge Tied
Load) power amplifier stage at the same time as using the RCA input for LFE. The High level
input will not work correctly and may cause your Digital or BTL Power Amplifier to enter
protection mode if this interface box is not used
Page 3
Location
Avoid using the “Pro 50Mk2” in the following locations:
*
Locations of extreme low or high temperatures, or extreme changes in temperature.
*
Sources of heat such as near commercial heaters, fires or other sources of heat.
*
Unstable locations or where the unit can fall due to vibration.
*
Locations with excessive moisture or dust.
*
Locations where electrical voltage varies.
Power Supply
*
When unplugging the AC adaptor from the outlet, be sure to grasp the adaptor. Attempting to unplug it by pulling on
the AC cable may damage the wiring or the mains socket on the amplifier.
* Always power-down amplifier and switch off before making any connections.
*
It is
dangerous
to use any power cable that is
cut
or
frayed
. If the power cable is damaged, stop using it
immediately, and have it repaired.
*
Do not plug in or unplug the AC adaptor with wet hands. Doing so may result in dangerous electric shock.
*
Do not remove the amplifier or touch any parts inside. Doing so may result in a dangerous electric shock, and could
damage the delicate electronic circuits. The voltages inside the amplifier are very dangerous.
*
Do not let water or other liquids, flammable materials, or metal objects such as pins get inside any of the input
sockets. These things can cause an electrical shock or short circuit the amplifier, and damage it. If the amplifier
should become wet, unplug the AC adaptor from the AC outlet at the wall first, and contact the manufacturers
directly.
There are NO user serviceable parts inside.
Precautions
Thank you very much and congratulations on choosing the MJ Acoustics Pro-50Mk2 Active Sub-
Bass System - a compact active lower octave loudspeaker, designed for stereo and multi-
channel use to provide you with outstanding performance. The use of a Subwoofer is essential
to provide a proper balanced spectrum of sound .
Please take a few moments to read this manual. The advice offered will enable you to get
the very best performance from your Pro 50Mk2 subwoofer.
The Pro 50Mk2 features a critically shaped paper pulp cone bass driver providing transparent
and dynamic bass registers. The Pro 50Mk2 has been specifically designed for use with stereo
and in multi-channel (AV) systems but can also be used on main front, rear and centre channels.
Using our specially designed enclosure, dedicated amplifier and active crossover filter system
you have purchased a musically accurate Active Sub-Bass System. By adding the Pro 50Mk2
powered sub-bass system to your audio equipment you will have the benefits of a transparent
and fully dynamic sound stage.
Introduction
MJ Acoustics Pro 50Mk2 User’s Manual
10/10/2006 (Pro – 50Mk2)