Liberty Acoustics LA-SUB SERIES User manual

1 of 4
http://www.libertyacoustics.com
LA-SUB SERIES SUBWOOFER
OPERATING INSTRUCTIONS
Thank you for purchasing this LA-SUB series subwoofer.
The following items are supplied with your subwoofer - should any item be missing, please contact your dealer:
Metal spikes with rings to adjust height individually (4 pcs)
Metal floor protectors (4 pcs)
Grille cover to protect the driver on the front
Power cable (see text in warning section)
An operation guide
WARNING
For safety reasons, please read the following instructions carefully before attempting to connect your LA-SUB series subwoofer to the mains.
The LA-SUB series subwoofer is not designed for permanent external use. Being a powered product, it would be damaged by rain water or
other contaminants entering into the amplifier via the vent holes and the wooden cabinet would be damaged if soaked with water.
As with all electrical products, make sure the factory pre-set voltage corresponds to mains of local power supply. If you are in
any doubt, contact your supplier for advice.
Excessive voltage will cause the mains fuse to blow or possibly even damage the internal
circuitry (if in doubt, ask your dealer/supplier).
Each power cord supplied has the international IEC connector for plugging into the amplifier panel at the rear.
USA and Canada
The USA style 15A plug with two flat blades should be used with subwoofer of AC Voltage 115V ~ 120V in operation.
IMPORTANT SAFETY PRECAUTIONS
CAUTION
To reduce the risk of electric shock, do not remove the rear panel. There are no user serviceable parts inside. Please refer all servicing to a
qualified engineer.
The lightning flash with the arrowhead symbol within an equilateral triangle is intended to alert the user to the presence of un-insulated
'dangerous voltage' within the product's enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons.
The exclamation mark within an equilateral triangle is intended to alert the user to the presence of important safety information featured within
this instruction manual.
VENTILATION
Slots and openings in the cabinet are provided for ventilation and to ensure reliable operation of the product. To protect it from overheating,
these openings must not be blocked or covered.
The openings should never be blocked by placing the product on a bed, sofa, rug, or other similar surface.
This product should not be placed in a built-in installation such as a bookcase or rack unless proper ventilation is provided and the
manufacturer's instructions have been adhered to.
SAFETY PRECAUTIONS
Read Instructions - All the safety and operating instructions should be read before the product is operated.
Retain Instructions - The safety and operating instructions should be retained for future reference.
Heed Warnings - All warnings on the product and the operating instructions should be adhered to.

2 of 4
http://www.libertyacoustics.com
Follow instructions - All operating and use instructions should be followed.
Cleaning - Unplug this product from the wall outlet before cleaning. Do not use liquid cleaners or aerosol cleaners. Use a damp cloth for
cleaning.
UNPACKING
The LA-SUB series subwoofer is heavy. (24 Kgs for LA-SUB10; 28 Kgs for LA-SUB12) For the sake of your health, ask people to assist
you in lifting and carrying the subwoofer around.
Get help from a family member or friend if this product is not installed by a
professional person.
The best way to remove the speaker from the carton is to open the top of the carton, roll it over with the flaps folded out and pull the carton
off, leaving the speaker in its protective polyethylene foam. Pull one foam frame off one at a time and lower the speaker to the floor carefully.
Remove the poly bag and keep it out of the hands of children and babies as it can cause suffocation.
GETTING STARTED
OVERVIEW
The LA-SUB series Subwoofer is an active loudspeaker. In other words, it has a built-in power amplifier to boost the signal level.
Therefore, there is no need for an external power amplifier to drive it . In addition, the LA-SUB series Subwoofer has a
complex filter circuit which boosts sub-sonic frequencies and is adjustable to allow it to be matched to different room sizes, shapes
and user requirements.
The rear panel controls provide a range of adjustments for this purpose.
The LA-SUB series subwoofer is designed to extend the low frequency response of both 2 channel and multi- channel systems, which each
demand a very different tonal balance.
This is described later, but control adjustment and placement in the listening room is
important, so please read these instructions carefully for best results.
QUALITY
The LA-SUB series subwoofer has a powerful driver unit. Model SUB 1 and SUB 2 are fitted with 8”
(210mm) and 10" (254mm) loudspeaker drivers respectively with enough magnet strength and
voice coil size to handle very high power levels for long periods without distress. Its cone
diaphragm is very stiff to keep distortion and coloration to a minimum.
The rubber suspension
surround is quite stiff, which also helps to reduce distortion and low frequency over-hang.
To further boost the fidelity of the LA-SUB series subwoofer, it has a very stiff cabinet made
with 20mm or 25mm MDF for the respective models.
In short, the LA-SUB series
subwoofer
is capable of extending frequency response of a stereo system of any quality or
price.
INSTALLATION AND SETUP
LA-SUB series subwoofers are factory pre-set in mains voltage. Make sure that subwoofer
purchased is of mains voltage appropriate to where you are applying it for us. Power cord
supplied should also be appropriate to local standard applicable for your mains supply socket.
If in doubt, do not proceed until you have contacted your dealer for advice or assistance.
Positioning the subwoofer is important if the best results are to be achieved. Place the subwoofer
where it can be connected easily to the mains power supply and to the output of the receiver or
stereo amplifier used for the rest of your system. Whilst this would normally be close to the
system, be prepared to move it around the room to gain the best results.
The Liberty Acoustics LA-SUB series subwoofer is a ‘down-firing’ speaker that is supported by
four metal spikes to hold it 50mm above the floor when the rings are screwed
tightly with the spikes. The overall height of space beneath the cabinet is adjustable to a
maximum of 5mm more by turning the spikes to the desired height, and to make them fixed by the
rings.
The mains supply can be left connected as it has a low current standby condition which is enabled when no signal is present for a short while.
Four pieces of 50mm-high carpet spikes are supplied with the subwoofer. The spikes can be adjusted to level the speaker and dig deep into
carpet to provide mechanical de-coupling of the device into the floor. Metal floor protectors are also supplied to prevent damage to
wooden flooring, if required.
In the case of a multi-channel system (5.1), connect a shielded cable from the sub-sonic (LFE) output of your receiver to the RCA jacks on
the back of the LA-SUB series subwoofer marked line in. You will note that there are two low level input sockets marked L
& R, which allow
for a stereo signal from your receiver or amplifier.
The specially designed summing circuitry in the LA-SUB series subwoofer combines the L&R low level input signals internally without
forcing the source signal into mono.
Set all the controls to the middle position and switch on the LA-SUB series subwoofer using the switch marked POWER. A small LED indicator
above the switch will light if everything is OK.
SUBWOOFER CONTROLS
You are now ready to set-up the system using the user guide or instructions from your receiver or DVD player. The sound balance can be
adjusted with the controls on the rear panel of the LA-SUB series subwoofer.

3 of 4
http://www.libertyacoustics.com
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.

4 of 4
http://www.libertyacoustics.com
TROUBLESHOOTING GUIDE
THERE IS NO POWER
Ensure that the IEC Power cable is connected securely.
Ensure that the plug is fully inserted into the wall socket and is switched on. Check the fuse in the IEC Power Cable
and subwoofer.
THERE IS NO SOUND
Ensure that the amplifier is set correctly.
Check if the signal cables are inserted correctly.
THERE IS A HUM COMING FROM THE SUBWOOFER
Ensure that all cable connections are secure.
WARRANTY
Your Liberty Acoustics subwoofer has been built to very high standard and should give many years of trouble free use. If within 2 years of the
purchase date it proves to be defective for any reason other than accident,
misuse, neglect, unauthorized modification, or fair
wear and tear, we will, at our discretion, replace the faulty parts without charge for labor in the region where the product is
purchased.
Your purchase invoice/receipt should be retained as it may be required should you need to claim on your warranty. This warranty is valid
only in region where the product is purchased and is in addition to your statutory rights. Service inquiries in regions
without an authorized distributor or dealer should be addressed first to the supplying dealer or agents of Liberty Acoustics.
Warranties granted in these countries are entirely at the discretion of the agent or distributor.
LIBERTY ACOUSTICS is constantly striving new design improvements, we
reserve the right to change or modify product specifications without prior notice
or obligation.
LA-SUB SERIES SPECIFICATIONS
This product is not magnetically shielded, so avoid placing it in proximity to a CRT television or computer monitor screen
Amplifier power output
1 80 Watts into 4 Ω load continuous (LA-SUB10)
240 Watts into 4 Ω load continuous (LA-SUB12)
Frequency response of System 35Hz to 120Hz with high and low filter settings at
max and min (LA-SUB10)
30Hz to 120Hz with high and low filter settings at
max and min (LA-SUB12)
Speaker impedance 4 Ohms
Sensitivity 89dB (LA-SUB10) 90dB (LA-SUB12)
Bass driver 10" (254 mm) metal chassis with reinforced paper cone for LA-SUB10.
12" (298mm) metal chassis with reinforced paper cone for LA-SUB12.
Filter compensation circuit Multi-element, high and low-pass filters with adjustable phase and active gain control
Cabinet 20mm MDF carcass in a very rigid enclosure for LA-SUB10
25mm MDF for LA-SUB12 (except the front that holds the driver unit, 20mm)
Finish Black Piano finish
Dimensions H x W x D mm 372 x 342 x 450 (LA-SUB10)
372 x 342 x 450 (LA-SUB12)
Weight 24Kgs (LA-SUB10)
28 Kgs (LA-SUB12)
Version 1.0 and Copyright © October 2008 LIBERTY ACOUSTICS