powersoft M-Force 01, User Manual

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Important notes
5
5 : 1.Preset HPF
In order to avoid damages to the mobile equipment, we
recommend to set a 15 Hz (at least) High Pass Filter on the
input signal path.
Since the M-Force is characterized by a very low load
impedance, any unwanted DC or low-end content would
pass through the motor to the diaphragm: without an input
HPF this would cause damages to the moving parts.
5 : 2.No mechanical load
It is highly recommended to limit motor excitation when
the same is not properly connected to a mechanical load.
5 : 3.Nuts tightening torque
We recommend to use a torque wrench in order to apply
the proper 15 N/m tightening torque.
We suggest to block the hub by means of an adjustable
wrench to avoid to twist the hub during assembly.
5 : 4.Engine diaphragm spacer nut
The ME001363.01 spacer, found in the spare part kit,
is a special spacer nut that mates the diaphragmn damper
onto the engine. It must be placed rounded side first into
the diaphragm and torqued to 15 N/m my holding the shaft
as inllusrtated in
paragraph 4.4.1 .
5 : 5.Rim and baffle cutout diameters
In order to avoid mechanical interference and provide
the right tightening force to the diaphragm, respect the
tolerance for the internal diameter of the rim and the baffle.
Rounding off the edge of the cut drastically reduces the
stress of the components.
5 : 6.Thermal considerations
The M-Force is characterized by high thermal inerthia.
This results in a slower variation of the body temperature
during normal operation: the motor appears to stay at low
temperature for long time (expecially during benchmark
tests), but after hours of operation, the system may reach
very high temperatures, making the heat transfer to the sur-
rounding environment an issue.
As any other traditional transducer, it is highly recom-
mended to favor the ventilation of the motor of the M-Force,
taking advantage of the air flow by the diaphragm and/or
exploiting the ventilation offered by the ducts of the cabinet.
When achievable, take into account configurations
where the motor is positioned outside the cabinet.
Note : The optional mounting brackets provided by
Powersoft are made of high thermal conductive Aluminium:
giving the fastening spots, this helps the heat transfer from
the M-Force motor.
Powersoft recommends to mount the M-Force
in a well ventilated position by means of
high thermal conductive brackets.
5 : 7.Mechanical strength of the cabinet
The M-Force is capable to produce very high static and
dynamic mechanical stresses to the cabinet. Two main ef-
fect must be taken into account:
f f
the internal sound pressure produced by the
movement of the diaphragm can rise up to 100 g/ cm
2
(9,8 kPa - 204,8 psf): this pressure dynamically
stresses the cabinet boundaries;
f f
the anchor points of the brackets to the cabinet are
highly stressed by the applied reactive force: take
into account to strengthen the overall structure and
properly tighten the fastening spots.
5 : 8.Mechanical balancing
The design of the cabinet shall take into account the
dynamic balancing of the center of mass of the M-Force
and diaphragm assembly.
Stating the high moving mass it is very important to
place the (moving) center of mass of the M-Force as close
as possible to the (static) center of mass of the cabinet.
This will reduce vibration and torque that make the cabinet
instable.
5 : 9.Acoustic load balancing
The diaphragm is subjected to high acoustic load. In
order to limit cone rocking it is highly recommended to
design the system so that the diaphragm is symmetrically
acoustic loaded.
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