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"WARNING"
“TO REDUCE THE RISK OF FIRE OR ELECTRIC
SHOCK, DO NOT EXPOSE THIS APPLIANCE TO RAIN
OR MOISTURE.”
SAFETY INSTRUCTIONS
1. Read Instructions - All the safety and operating instructions
should be read before the appliance is operated.
2. Retain Instructions - The safety and operating instructions
should be retained for future reference.
3. Heed Warnings - All warnings on the appliance and in the
operating instructions should be adhered to.
4. Follow Instructions - All operating and use instructions
should be followed.
5. Water and Moisture - The appliance should not be used
near water - for example, near a wet basement, or near a
swimming pool, and the like.
6. Carts and Stands - The appliance should be used only with
a flight case or stand that is recommended by the
manufacturer.
7. Wall or Ceiling Mounting - The appliance should be
mounted to a wall or ceiling only as recommended by the
manufacturer.
8. Ventilation - The appliance should be situated so that its
location or position does not interfere with its proper
ventilation. For example, the appliance should not be
situated such that may block the ventilation openings: or,
placed in a built-in installation, such as a bookcase or
cabinet that may impede the flow of air over the amplifier
panel.
CAUTION:
TO PREVENT ELECTRIC SHOCK, MATCH WIDE BLADE
OF PLUG TO WIDE SLOT. FULLY INSERT.
ATTENTION:
POUR EVITER LES CHOCS ELECTRIQUES,
INTRODUIRE LA LAME LA PLUS LARGE DE LA FICHE
DANS LA BORNE CORRESPONDANTE DE LA PRISE ET
POUSSER JUSQU AU FOND.
9. Heat - The appliance should be situated away from heat
sources such as radiators, heat registers, or other
appliances that produce heat.
10. Power Sources - The appliance should be connected to a
power supply only of the type described in the operating
instructions or as marked on the appliance.
11. Grounding or polarization - Precautions should be taken
so that the grounding or polarization means of an
appliance is not defeated.
12. Power Cord Protection - Power supply cords should be
routed so that they are not likely to be walked on or
pinched by items placed upon or against them, paying
particular attention to cords and plugs, convenience .
receptacles, and the point where they exit from the
appliance.
13. Cleaning - The appliance should be cleaned only as
recommended by the manufacturer.
14. Nonuse Periods - The power cord of the appliance should
be unplugged from the outlet when left unused for a long
period of time.
15. Object and Liquid Entry - Care should be taken so that
objects do not fall and liquids are not spilled onto the
enclosure paying particular attention to the amplifier
panel.
16. Damage Requiring Service - The appliance should be
serviced by qualified service personnel when:
A. The power supply cord or the plug has been damaged;
or
B. Objects have fallen, or liquid has been spilled onto the
appliance;
or
C. The appliance has been exposed to rain;
or
D. The appliance does not appear to operate normally or
exhibits a marked change in performance;
or
E. The appliance has been dropped, or the enclosure
damaged.
17. Servicing - The user should not attempt to service the
appliance. All servicing should be referred to qualified
service personnel.
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
Caution: To Reduce Risk of Electric Shock,
Do Not Remove Amplifier.
No User Serviceable Parts Inside.
Refer Servicing to Qualified Personnel.
The lightning flash with arrowhead symbol within an
equilateral triangle is intended to alert the user to the presence
of uninsulated “dangerous voltage” within the product’s
enclosure that may be of sufficient magnitude to constitute a
risk of electric shock to persons.
The exclamation point within an equilateral triangle is
intended to alert the user to the presence of important
operating and maintenance (servicing) instructions in the
literature accompanying the appliance.
MJ Acoustics Pro 50Mk2 User’s Manual
10/10/2006 (Pro – 50Mk2)
Page 7
MJ Acoustics Pro 50Mk2 User’s Manual
I.S.P.
(Intelligent 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.
Connect your subwoofer to your audio system using the low level phono interconnect supplied or
the optional high level lead. Please refer to the instructions that came with the high level lead for
this connection.
Please ensure:
All controls are set to minimum gain, 0° phase, and 20hz frequency contour
on first power-up.
For downward firing subwoofer speakers the phase control should be set to 0°. Remember that
these are just starting points and it is suggested that you experiment with this setting over a
period of time to determine the best position of the phase control relative to your subwoofer
placement and the natural acoustics of the room.
After powering up the sub, audition a piece of music you are familiar with and set the main audio
system volume to your normal listening level. Slowly increase the gain control on your Pro 50Mk2
to approx one quarter to half its travel (12 o’clock position). You should now be experiencing
sub-bass in your overall mix. How much bass output is determined by the position of the gain
control.
Now adjust the frequency contour until you hear the subwoofer output the bandwidth of bass
frequencies your main speakers lack. For example, most main speakers roll off the bass output
at around 40hz – 80hz so this is where the subwoofer should take over. For AV/LFE signals set
the Rolloff to 90Hz as the LFE channel is already filtered within the AV processor to output
frequencies from 80Hz and below.
SET-UP HINTS & TIPS
10/10/2006 (Pro – 50Mk2)