3
Run in procedure
FLI UNDERGROUND recommends that you follow the run in procedure for the
subwoofer detailed below.
When your subwoofer is used for the
fi
rst time naturally like most brand new items it is very
stiff and rigid, it will take time for the moving parts of this subwoofer to loosen up before it
will be ready to deliver its full potential.
For the
fi
rst 30 hours it is recommended that you play the subwoofer initially at low to medium
volumes, gradually increasing the volume level as time progresses. As a guide, if you listen to it for
1 hour every day it will take a month for the speaker to run in properly. You will notice a big change
in the sound of the subwoofer over this period, as the spider and surround begin to run in the sound
will get deeper and punchier, also the output of it will increase as the suspension loosens up.
A new subwoofer is like a new car engine, it needs a few thousand miles before you can drive it to its full
potential, driving it into the ‘red line’ from the
fi
rst day will mean engine damage is certain and will not be
covered by warranty and the same applies to the subwoofer. Failure to follow this simple procedure is the
most common reason for a subwoofer to fail after a very short period of time.
Installation
The FLI UNDERGROUND subwoofer can be installed in a variety of different ways, the most suitable will
depend upon your application.
Free-air installation
The FLI UNDERGROUND subwoofer can be mounted free-air, but this does not mean that the woofer can
work without any form of enclosure. What it does mean is that the enclosure can be very large and therefore
the subwoofer can utilise the vehicle boot as an enclosure.
The subwoofer needs to be mounted to a rigid panel as excess vibration will result in poor sound quality.
The panel or baf
fl
e, should also seal the output from the front of the subwoofer from the output from the rear
otherwise poor sound quality, known as phase error, will occur. This simply means that the output from the rear
of the woofer will cancel out the output from the front resulting in a loss of bass.
As the enclosure in free-air applications is so large it is worth noting that the power handling of the subwoofer is
reduced to half that of the same woofer in a measured enclosure. Please take this into account when choosing
your ampli
fi
er. The sound quality of a free-air mounted subwoofer will not match that of the same subwoofer
mounted in a measured enclosure. However in applications where building a traditional enclosure is impossible,
free-air mounting will add increased bass response to your system.
