Legacy LA4670-SL BK User manual

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SPECIFICATIONS
If you are incorporating more than one amplifier. Please consider adding a P.W.M. preamp E.Q. to
boost head unit signals, so you can obtain maximum power, with minimum power supply strain.
You will find that you can reduce your gains to about 50% and achieve the same output wattage to
your speakers which will leave lots of dynamic headroom for Strong bass transients. A P.W.M. E.Q.
will deliver four times the voltage to your amps and reduce the possibility of engine noise.
Congratulations on your purchase of a LEGACY ICON Car Amplifier. The unit is the result of an
extensive engineering project to create the finest automotive high fidelity product available. It is
superior in performance and has the ability to operate under extreme environmental conditions.
To fully understand the unit capability, please read this manual carefully and follow all of the
instructions regarding its use and installation.
INTRODUCTION
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MODELS
Amplifiers: LA4670-SL(BK), LA2770-SL(BK),LA2970-SL(BK)
Built-in Crossover
The 2 CH and 4 CH amplifiers are feature a continuously variable low pass and fixed high pass
crossover.
The monoblock amplifiers feature adjustable low pass
crossovers and fixed high pass crossovers, as well as Bass Boost control.
RMS Power @ 4 ohms
Max Power @ 2 ohms
Bridged Power @ 4 ohms
Channel separation
THD
Input Sensitivity low
high
Crossover frequency
Signal to noise ratio (JIS-A WTD)
Frequency response
MODELS
RMS Power @ 4 ohms
Max Power @ 2 ohms
Channel separation
THD
Input Sensitivity
Crossover frequency
Signal to noise ratio (JIS-A WTD)
Frequency response
low
high
FEATURES
Amplifiers: LA1110-SL(BK), LA1270-SL(BK)
Bridgeable MOSFET Amplifier
Tri-Mode Capable
Heavy Duty Aluminum Alloy Heatsink
Class A-B Operation
Continuously Variable Low Pass Crossover (30 Hz to 300 Hz)
High Pass Crossover (200 Hz fixed)
Continuously Variable Input Gain Control
Silver Plated RCA and Speaker Level Inputs
Remote Turn On/ Turn Off Circuit
MOSFET Pulse Width Modulated Power Supply
2 Ohm Stable Stereo Operation with Output Power Increase
Soft Turn-On Circuit
Thermal and Speaker Short Protection Circuitry
LED Power and Protection Indicators
Monoblock MOSFET Amplifier
Heavy Duty Aluminum Alloy Heatsink
Class A-B Operation
Continuously Variable Low Pass Crossover:
LA1110-SL(BK) - 35Hz to 160Hz
LA1270-SL(BK) - 40Hz to 130Hz
High Pass Crossover (200 Hz fixed)
Continuously Variable Input Gain Control
Bass Boost Control:
Silver Plated RCA and Speaker Level Inputs
Remote Turn On/ Turn Off Circ uit
MOSFET Pulse Width Modulated Power Supply
2 Ohm Stable Stereo Operation with Output Power Increase
Soft Turn-On Circuit
Thermal and Speaker Short Protection Circuitry
LED Power and Protection Indicators
LA1110-SL(BK) - swith 0 or 18dB
LA1270-SL(BK) - variable 0 to 12dB
Remote Subwoofer Level Control

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2 Ohm Operation
At 2 Ohms,the amplifiers willincrease their outputpower by approximately 50%. The current
draw will alsoincrease by aboutthe same amount,so be sure you have enough current to run
the amplifiers intoa 2 Ohmload. If youlack adequate current, your music reproduction will be
distorted.
Please note: Thegain control ofany car audioamplifier should not be mistaken for a volume
control. It isa sophisticated device,designed to matchthe output level of your audio source unit
to the inputlevel of theamplifier. Donot adjust this input level to maximum unless your input
level requires it.Ignoring these instructionswill result inan input overload to the amplifier, and
excessive audio distortion.It can alsocause the protectioncircuit to engage.
Your amplifier was designed to operate effectively at loadsdown to 2Ohms. This means that
you can installfour 8 Ohmspeakers per channelwhen using parallel wiring. Increasing the
number of woofersper channel atlow frequencies (upto 100Hz) produces an acoustic coupling
effect. This acoustic coupling increases your power output by 3 dBper speaker,or equivalent of
an additional 10Wto each speaker.
Electrical Wiring
Fuses
Fuses protect boththe amplifier andthe electrical systemof your vehiclefrom fault conditions.
If you mustreplace the fusein your amplifier, use a fuse of exactly the same typeand rating.
A different type or rating of fuse may result in damage or fire.
Mounting the Amplifier
Mark the location for the mounting screw holes by positioning the amplifier where you wish to
install it and use ascribe (or one of the mounting screws) inserted in each mounting hole to
mark the mounting surface. If the mounting surface is carpeted, measure the hole centers and
mark with a felt tippen.
Drill pilot holes in the mounting surface for the mounting screws and insert the mounting screws
into these holes. Tighten them securely.
Note: Be sure to take note of any wires, lines or other devices in your vehicle which may be
located behind any mounting surface!
Remote Subwoofer LevelControl
The monoblock amplifiers (except 2ch /4ch amplifiers)are equipped with a dashboard mount
remote subwoofer level control, run the supplied dashboard remote control from the front panel
of your amplifier. By turning the level knob clockwise, you will increase the output of low
Frequencies.
Yourpower amplifier is equippedwith easytop accessscrew terminalsin orderto ensure
excellent electricalcontact andto resistcorrosion.
When making electricalconnections to theamplifier, pleaseobserve the following:
:- Use atleast 8 gaugeor heavier wirefor power and ground connections.
:- Wire theamplifier directly tothe car battery.
:- For theground connection, usethe shortest possiblewire to a good chassis ground point.
:- Wire theRemote connection tothe remote turn-onlead of your equalizer or head unit. In some
cases this maybe the powerantenna lead ofthe head unit.
High Level Inputs
If the HIGHLEVEL INPUTS areused, do notuse the LOW LEVEL INPUTS RCA inputs at the
same time.
HEAD UNIT
From HEAD
UNIT
SPEAKER
OUTPUT
LEFT CHANNEL( +)
LEFT CHANNEL( -)
CHASSIS GROUND
RIGHT CHANNEL (-)
RIGHT CHANNEL (+)
Monoblock Amplifier: LA1110-SL/LA1110-BK
Protection Circuitry
The amplifier protection circuitry will disable the amplifier if input overload, short circuit or extremely high
temperature conditions are detected. When the protection mode is in operation, the LED indicator on the
front panel will be illuminated, indicating the amplifier has gone into a self-preservation mode.
If you observe that the protection LED is lit, please check the system carefully to determine what has
caused the protection circuit to engage. The amplifier can be reset by turning the remote power off
and then on again. If the amplifier shuts down due to a thermal overload condition, please allow it to
cool down before restarting. If the amplifier shut down because of an input overload or short circuit,
be sure to repair these conditions before attempting to power up the amplifier again.
HEAD UNIT
From HEAD
UNIT
SPEAKER
OUTPUT
LEFT CHANNEL( +)
LEFT CHANNEL( -)
CHASSIS GROUND
RIGHT CHANNEL (-)
RIGHT CHANNEL (+)
Monoblock Amplifier: LA1270-SL/LA1270-BK

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Low Level Input Wiring
Two Channel Amplifier
REAR
INPUTS
High Level Inputs
If the HIGHLEVEL INPUTS areused, do notuse the LOW LEVEL INPUTS RCA inputs at the
same time.
HEAD UNIT
From HEAD
UNIT
SPEAKER
OUTPUT
LEFT CHANNEL( +)
LEFT CHANNEL( -)
CHASSIS GROUND
RIGHT CHANNEL (-)
RIGHT CHANNEL (+)
Two Channel Amplifier:
HEAD
UNIT
Four Channel Amplifier:
1 CHANNEL (+)
1 CHANNEL (-)
CHASSIS GROUND
2 CHANNEL (-)
2 CHANNEL (+)
CHANNEL 3 (+)
CHANNEL 3 (-)
CHASSIS GROUND
CHANNEL 4 (-)
CHANNEL 4 (+)
From HEAD
UNIT
Speaker
Output
Monoblock Amplifier: LA1270-SL/LA1270-BK
From OUTPUT
of HEAD UNIT
From OUTPUT
of HEAD UNIT
FRONT
INPUTS
Low Level Input Wiring
From OUTPUT
of HEAD UNIT
Monoblock Amplifier: LA1110-SL/LA1110-BK
Four Channel Amplifier
++
To REMOTETURN-ON
from HEAD UNIT
SUBWOOFER
Speaker
SPEAKER
IMPEDANCE
2-8 OHMS
Monoblock Amplifiers:
LA1110-SL/ LA1110-BK/ LA1270-SL/ LA1270-BK
POWER AND SPEAKER WIRING

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++
SUBWOOFER MINIMUM
IMPEDANCE 8 OHMS!
++
++
HIGH PASS
FILTER (CAPACITORS)
SPEAKER IMPEDANCE
4 - 8 OHMS!
LOW PASS
FILTER (INDUCTOR)
Full Range
Speakers
To REMOTETURN-ON
from HEAD UNIT
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2-Channel Amplifiers:
Two Channel Mode
To REMOTETURN-ON
from HEAD UNIT
++
LEFT
SPEAKER
RIGHT
SPEAKER
++
Bridged Mode
To REMOTETURN-ON
from HEAD UNIT
++
SUBWOOFER
Speaker
SPEAKER
IMPEDANCE
4-8 OHMS
SPEAKER
IMPEDANCE
2-8 OHMS
Dual Tri-Mode Speaker Wiring
Toengage the amplifier in this mode, place the Crossover (Subwoofer) switch
in the "FULL" position. Use a 100v non-polar capacitor for a high pass
crossover and a wire coil inductor to block high frequencies from the
Subwoofer, as shown in the figure below. Please review the table below for
inductor and capacitor component values to determinethe desired crossover
frequencies.
Component ValuesComponent Values
for 6dB Passive
Crossover
for 6dB Passive
Crossover
Frequency Inductor Capacitor
80Hz 7.5mH 470uF
100Hz 6.5mH 330uF
120Hz 5.5mH 330uF
150Hz 4mH 220uF
Tri-Mode Operation is a uniquefeature which allowstwo channel of an
amplifier to drivea subwoofer operatedin MONO mode, while
simultaneously driving fullrange speakers inSTEREO.
Four Channel Speaker Wiring
++
++
++
++
CH 3
SPEAKER
CH 1
SPEAKER
CH 2
SPEAKER
CH 4
SPEAKER
Bridged Speaker Wiring
Four Channel Amplifiers:
++
SUBWOOFER
SPEAKER
++
SUBWOOFER
SPEAKER
SPEAKER IMPEDANCE
4 - 8 OHMS!
SPEAKER
IMPEDANCE
4 - 8 OHMS!
To REMOTETURN-ON
from HEAD UNIT
To REMOTETURN-ON
from HEAD UNIT

Dual Tri-Mode Speaker Wiring
Toengage the amplifier in this mode, place the Crossover (Subwoofer)
switch in the "FULL" position. Use a 100v non-polar capacitor for a high
pass crossover and a wire coil inductor to block high frequencies from
the Subwoofer, as shown in the figure below. Please review the table
below for inductor and capacitor component values to determine the
desired crossover frequencies.
Component Values
for 6dB Passive Crossover
Component Values
for 6dB Passive Crossover
Frequency Inductor Capacitor
80Hz 7.5mH 470uF
100Hz 6.5mH 330uF
120Hz 5.5mH 330uF
150Hz 4mH 220uF
++
++
SUBWOOFER
SPEAKER IMPEDANCE
4 - 8 OHMS!
SPEAKER
IMPEDANCE
4 - 8 OHMS!
++++
CH 1
SPEAKER
CH 2
SPEAKER
SUBWOOFER MINIMUM
IMPEDANCE 8 OHMS!
HIGH PASS
FILTER (CAPACITORS)
LOW PASS
FILTER (INDUCTOR)
++++
HIGH PASS
FILTER (CAPACITORS)
LOW PASS
FILTER (INDUCTOR)
CH 3
SPEAKER
CH 4
SPEAKER
SUBWOOFER
SUBWOOFER MINIMUM
IMPEDANCE 8 OHMS!
Tri-Mode Operation is a uniquefeature which allowstwo channel of
an amplifier todrive a subwooferoperated in MONOmode, while
simultaneously driving fullrange speakers inSTEREO.
To REMOTETURN-ON
from HEAD UNIT
Before you drillor cut anyholes, investigate yourcar's layout very carefully. Takecare when
you work nearthe gas tank,fuel lines, hydrauliclines and electrical wiring.
Do not operate theamplifier when it is notmounted. Attach all audio system components
securely within the automobile to preventdamage, especially in case ofan accident.
Precautions
Do not mount this amplifier so that the wire connections are unprotected or in a pinched
condition, or likely to be damaged by nearby objects.
Before making or breaking power connections in your system, disconnect the vehicle battery.
Confirm that your head unit or other equipment is turned off while connecting the input jacks
and speaker terminals.
If you need to replace the power fuse, replace it only with a fuse identical to that supplied with the system.
Using a fuse of different type or rating may result in damage to your system which isn't covered by the
manufacturer's warranty.
Confirm that allterminal strip connectionsare secure andtight.
Check both in-lineand built-in fuses.Both the "+12V"and the "REMOTE" terminals
must have +12Vreferenced to chassisground.
Check the "BALANCE" control onthe head unit (orother source) to verifythat it
is set toits midpoint.
If you are using the Low Level RCA Inputs, reverse the input plugs at the amplifier
(switches the R with the L). If the channel which is silent switches to other side,
the problem is either in the head unit/other source or the connecting tables.
If the noise is a "whine" whose pitch follows the engine speed, confirm that the
amplifier and any other signal sources ( head unit, etc.) are properly grounded.
If the noise is a "clicking" or "popping" noise whose rate follows the engine speed, this
usually means that the vehicle is equipped with resistor spark plugs and wires, or that
the ignition is in need of service.
Troubleshooting
Before removing youramplifier, referto the listbelow and followthe suggested
procedures. Always testthe speakers andtheir wires first.
No Output
Confirm that the audio signal source (car radio, equalizer, etc.) is connected and is
supplying output signal. To check if the amplifier is supplying signal, unplug the RCA
cables from the signal source (but leave them plugged into the amp). Gently tap the
center pin of each of the disconnected RCA plugs with your finger. This should
produce a noise (feedback) in your speakers.
Only one
channel
works
Confirm that all speakerstrip connections are secureand tight.
Weak Output
Readjust the Input Sensitivity Control to better suit the input signal.
Noise in the
Audio
Check the routing of the speaker and input wires to make sure they are not adjacent to
wires which interconnect lights and other accessories.
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