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Low Level Input (Line In as shown)
If your amplification system has a dedicated subwoofer output, it should be connected to the
input jacks (indicated as L&R) by using a cable with one end being split into 2 RCA jacks for
signal passage from the CD player. However, when signals are directed from a pair of RCA
output jacks of the pre-amplifier or an integrated amplifier, then a pair of cables with RCA
plugs should be used.
Low Level Output (Line Out as shown)
The low level output is filtered by the LA-SUB series subwoofer circuitry to provide a signal back
to the L&R front speakers that has had its low frequencies removed. The LA-SUB series
subwoofer will provide these low frequency signals exclusively to prevent a conflict.
High Level Input (Speaker Level In)
If your receiver system does not have a dedicated subwoofer line output, your subwoofer must be
connected via the Speaker Level Inputs terminals on the rear panel. Connection should be made
from the speaker terminals on your amplification system to the Speaker Level Inputs Connections.
Note: Only connect using line level inputs
OR
Speaker Level inputs.
DO NOT USE BOTH METHODS OF CONNECTION AT THE SAME TIME.
Volume
As a starting point, set the output of your receiver or decoder to 0dB level and then adjust the level
of the subwoofer to suit the room using the volume control on the rear panel. Thereafter, small
adjustments can be made more easily using the volume control on your receiver, via its remote
control, rather than adjusting the volume from the back of the LA-SUB series subwoofer.
Low Pass Filter (Low Pass Frequency as shown)
Adjustment is necessary to extend or reduce the low frequencies the subwoofer is able to produce
so that it can compensate for the small size of the LA-SUB series subwoofer and your room
acoustics. Some movie passages contain massive amounts of low frequency information at intervals,
so care should be taken not to set the volume and low pass filter such that it causes distortion or
limiting, due to being played too loud. It is better to use two subwoofers at a lower level setting than
over-drive one. Your room size and personal sound preferences will determine how much sound
pressure level (SPL) is required to create a realistic performance.
N.B
. Not everyone will appreciate the effect of sub-sonic movie effects. Even if you think they are
great, please remember that low frequencies travel through walls much more easily than high
frequencies, so please give a thought to neighbors or other family members who don't share your
passion.
Phase
Adjustment is necessary to properly integrate the output of the LA-SUB series
subwoofer to match the respective phase of the front, centre and rear speakers in your 5.1
system. Phase describes the polarity of the sound waves traveling to your ears. Positive means
moving forward and negative means moving back. If the sound from your front speakers is
designed to be more positive at their low frequency extreme, it will be necessary to adjust the
output of the LA-SUB series subwoofer to also be positive, otherwise they will tend to cancel one
another out and reduce the level or distort or color the sound. As every situation will be different
and speakers may vary from make to make and room to room, adjustments should be done simply
by trial and error. You will easily hear which setting best suits your system after you run it with a
signal and adjust the Phase until you hear the most pleasing result.
Power Switch
This switch turns the subwoofer 'ON' or 'OFF'. When there is no disruption to signal passage to
the subwoofer, then the pilot light will become GREEN. Otherwise it would be RED even the button
is at ON position.
IEC Socket (Mains)
Connect to an appropriate mains socket via the IEC Power Cable supplied.
POSITIONING AND TUNING
Remember that low frequencies have a longer wave length and sound waves travel to the ear in waves. It therefore may be necessary to
move your subwoofer to different positions to completely suit your requirement or taste. If you require more or less power at low
frequencies, it can be affected by the proximity to an adjacent wall or boundary. Each wall or boundary will further enforce the effect
of the woofer so, moving it closer or further away from a rear or side wall will change the sound effect dramatically. Corners double the
effect as there are two boundaries.
The LA-SUB series subwoofer has been designed to match medium to small rooms, with an area of approximately 10-20 square
meters. If higher power or larger rooms are used, it may be necessary to increase the number of subwoofers used in a single installation.
SOUND PRESSURE LEVELS
It is very easy to get used to high sound pressure levels as the human brain compensates for the level by effectively reducing the
perceived level the ear is receiving and allows the person to become used to higher and higher levels until the pain threshold is
reached. It is therefore necessary to be aware of this and avoid reaching this sublime state before serious or permanent damage is caused
to ones ears. Remember that hearing damage, as with all nerve damage, is irreversible.