impact LK 705 User manual

LK 705
Confirm that all terminal strip connections are secure and tight.
Check both in-line and built-in fuses. Both the "+12V" and the "REMOTE" terminals must
have +12V referenced to chassis ground.
Check the "BALANCE" control on the head unit (or other source) to verify that it is set to
its 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 cables.
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 wi th resistor spark plugs and wi res, or that
the ignition is in need of service.
Troubleshooting
Before removing your amplifier, refer to the list below and follow the suggested
procedures. Always test the speakers and their wires first.
No Output
Confirm that the audio signal source (car radio, equalizer, etc.) is connected
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.
and is supplying
Only one
channel
works
Confirm that all speaker strip connections are secure and 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.
-12-

SPECIFICATIONS
The amplifier protect ion circui try will disabl e the amplifier if the inpu ts are overl oade d, short -circui ted or
extr emely high temperat ure cond itions are detect ed. When the protect ion mode is in op erat ion, the LED indi cat or
on the front panel will be illum inated, indi cat ing the am plifier has gone into a sel f-pr eservat ion mod e.
attempting to power up the amplifier again.
If you observe that the protec tion LED is lit, plea se chec k the sys tem ca ref ully to determine wha t has ca us ed the
protec tion ci rcu it to eng age. The ampl ifier can be res et by tur ni ng the rem ot e pow er of f and then on again. If the
ampl ifier shut s dow n due to a ther mal ove rload con di tion, pl ease al low it to cool dow n bef ore pow ering up. If the
ampl ifier shut s dow n bec ause of an input ove rload or shor t circu it, be sur e to repa ire thes e con di tions bef or e
amplifiers have been designed with 100% MOSFET power supplies,
ensuring extremely quick switching response for plenty of clean power.
The IMPACT LK series
Protection Circuitry
FEATURES
Heavy Duty Aluminum Alloy Heatsink
Class A-B Operation
SUB Ch: Continuously Variable Low Pass Crossover
(35Hz to 155Hz)
18dB Bass Boost
Phase Shift
Remote Subwoofer Level Control
Ch 1-2 High Pass Crossover (80 - 6.000 Hz)
Ch 3-4 High Pass Crossover (80 - 1.500 Hz)
Ch 3-4 Low Pass Crossover (300 - 6.000 Hz)
Continuously Variable Input Gain Control
Nickel 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
Dimensions: 240x50x550 mm
Five Channel Amplifier LK 705
Five Channel Bridgeable MOSFET Amplifier
-2- -3-
S/N Ratio
Low Pass Crossover (Variable)
Bass Boost (50 Hz)
Frequency Response
THD@ RMS Output
Fuse Values
Power RMS @ 4 Ohms
Remote Subwoofer Level Control
Total
Power RMS @ 2 Ohms
Bridged Power (4 Ohms)
High Pass Crossover
Tri-mode Operation
MODEL LK 705
Channnel Separation
Damping Factor
Max Power 1.500 W
(240 L x 50A x ...P) 550
Dimensions mm.
Ch 1-2
350 W
Ch 3-4
350 W
SUB Ch
200 W x 1
300 W x 1
800 W
30 - 155 Hz
300 - 6.000 Hz
80 - 1.500 Hz
80 - 6.000 Hz
0 - 18 dB
Yes
YesYes
9 Hz - 50 KHz
0.01 %
35A x 2
100
90 dB
> 93
60 W x 2
80 W x 2
160 W x 1
60 W x 2
80 W x 2
160 W x 1
420 W
620 W

Electrical Wiring
the protection circuit to engage.
The IMPACT LK Series amplifier was designed to operate effectively at loads down to 2 Ohms.
This means that you can install four 8 Ohm speakers per channel when using parallel wiring.
Increasing the number of woofers per channel at low frequencies (up to 100Hz) produces an
acoustic coupling effect. This acoustic coupling increases your power output by 3 dB per speaker.
When operating at 2 Ohms, the amplifier will increase their output power by approximately 50%. The
current draw will also increase by about the same amount, so be sure you have enough current to run the
amplifiers into a 2 Ohm load. If you lack adequate current, your music reproduction will be distorted.
Please note: The gain control of any car audio amplifier should not be mistaken for a volume control. It is
a sophisticated device, designed to match the output level of your audio source unit to the input level of
the amplifier. Do not adjust this input level to maximum unless your input level requires it. Ignoring these
instructions will result in an input overload to the amplifier, and excessive audio distortion. It can also cause
2 Ohm Operation (in stereo mode)
Wire the amplifier directly to the car battery. Make sure there is circuit protection (such as a fuse) on the
positive power lead, within 18 inches of the battery.
All IMPACT LK series power amplifiers are equipped with easy top access screw terminals. These
terminals are n in order to ensure excellent electrical contact and to resist corrosion.ickel-plated
When making electrical connections to the amplifier, please observe the following:
Use at least 8 gauge or heavier wire for power and ground connections.
For the ground connection, use the shortest possible wire to a good chassis ground point.
Wire the Remote connection to the remote turn-on lead of your equalizer or head unit. In some cases
this may be the power antenna lead of the head unit.
Fuses
Fus es prot ect bot h the ampl ifier and the electrical system of you r vehicle from faulty con dition s.
replace the fuse in you r ampl iifier, use a fuse of exactly the same type and rating. A different type or rating may
result in damage or cause a fire.
If you mus t
Mounting the Amplifier
Mark the location for the mounting screw holes by positioning the amplifier where you wish to install it and
use a scribe (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 tip pen.
Drill pilot holes in the mo unting surface for the mo unting screws and insert the mo unting
holes. Tighten them securely.
screws into these
Note: Before beginning your installation, be sure to take note of any wires, lines or other devices in your
vehicle which may be located behind any mounting surface.
-4- -5-
REAR
INPUTS
5 Channel Amplifier LK 705 - Input wiring
HEAD UNIT with Front/Rear/Sub OUTPUT
FRONT
INPUTS
SUB
INPUTS
If your HEAD UNIT have less than 3 RCA output, you can match the requested
INPUT plugs by using some “Y adapter ”

-6- -7-
To REMOTE TURN-ON
from HEAD UNIT
GROUND
To BATTERY
Sub woofer Speaker
+
Power
Batt Rem Gnd
Sub
CH 1 CH 2
Bridged
CH 3 CH 4
Fuses
Ch1
SPEAKER
Ch2
SPEAKER
Ch3
SPEAKER
Ch4
SPEAKER
5 Channel Amplifiers LK 705
To REMOTE TURN-ON
from HEAD UNIT
GROUND
To BATTERY
Sub woofer Speaker
+
Power
Batt Rem Gnd
Sub
CH 1 CH 2
Bridged
CH 3 CH 4
Fuses
Ch1-2
SPEAKER
Ch3-4
SPEAKER
Speaker wiring
Bridged speaker wiring
To REMOTE TURN-ON
from HEAD UNIT
GROUND
To BATTERY
Sub woofer Speaker
+
Power
Batt Rem Gnd
Sub
CH 1 CH 2
Bridged
CH 3 CH 4
Fuses
Ch1
SPEAKER
Ch2
SPEAKER
Ch3
SPEAKER
Ch4
SPEAKER
Tri-mode speaker wiring
+
LOW PASS
FILTER (INDUCTOR)
SPEAKER
IMP EDAN CE
4 - 8 OHMS!
SPEAKER
IMP EDAN CE
4 - 8 OHMS!
SUBWOO FER MI NIMU M
IMP EDAN CE 8 OH MS!
Tri-Mode Speaker Wiring Two Channel Amplifier
Component ValuesComponent Values
for 6dB Passive Crossoverfor 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 unique feature which allows a two channel amplifier to drive a sub-woofer operated
in MONO mode, while simultaneously driving full range speakers in STEREO.
Connect the NEGATIVE SPEAKER TERMINAL to the
RIGHT CHANNEL NEGATIVE AMPLIFIER TERMINAL.
Connect the POSITIVE SPEAKER TERMINAL to the
LEFT CHANNEL POSITIVE AMPLIFIER TERMINAL.
Connect the NEGATIVE SPEAKER TERMINAL to the
RIGHT CHANNEL NEGATIVE AMPLIFIER TERMINAL.
Connect the POSITIVE SPEAKER TERMINAL to the
LEFT CHANNEL POSITIVE AMPLIFIER TERMINAL.
To engage 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 subwofer, as shown in the figure below. Pls review the table below
for inductor and capacitor component value, to determine the desired
crossover frequencies

-8- -9-
The IMPACT LK 705 is specially designed for maximum adjusting flexibility.
Depending to X-over regulation of the different channels, you can tune the final result exaclty to
your request.
SUB Channel can be adjusted as follows:
X-over: Full or Low Pass (30 to 155 Hz)
Bass Boost; (0 / +18 dB at 50 Hz)
Phase shift: (0 - 180°)
X-over setting
Channels 1-2 can be adjusted as follows:
X-over: Full or High Pass (80 to 6.000 Hz)
Channels 3-4 can be adjusted as follows:
High Pass X- over: Full or High Pass (80 to 1.500Hz)
Low Pass X-over: Full or Low Pa ss (300 to 6.000Hz)
This combination of Low / High Pass must be adjusted properly to get the results you want.
Pls note that if Low Pass frequency point is set lower than High Pass frequency point,
the output of the Channel 3-4 will be void.
Sub Channel: Subwoofer: Low Pass 100 Hz
Channel 1-2: 2 way system with passive x-over: High Pass = 80 Hz
Channel 3-4: 2 way system with passive x-over: Low Pass = Full - High Pass = 80 Hz
20 100 1 KHz 10 KHz
0 Db
5 Channel Amplifier LK 705 - X-Over Setting
20 100 1 KHz 10 KHz
Sub Ch Ch 1-2-3-4
-3 Db
-9 Db
-6 Db
0 Db
-3 Db
-9 Db
-6 Db
Sub Channel: Subwoofer: Low Pass 100 Hz
Channel 1-2: Tweeter: High Pass = 6.000 Hz
Channel 3-4: Mid Bass: Low Pass = 6.000 Hz - High Pass = 80 Hz
Sub Ch Ch 1-2Ch 3-4
System 1: Subwoofer + Front System + Rear System
System 2: Subwoofer + 2 Way Active Front System
20 100 1 KHz 10 KHz
0 Db
-3 Db
-9 Db
-6 Db
Sub Channel: Subwoofer: Low Pass 100 Hz
Channel 1-2: 2 Way Front System: High Pass = 300 Hz
Channel 3-4: Kick Bass: Low Pass = 300 Hz - High Pass = 80 Hz
Sub Ch Ch 1-2Ch 3-4
System 3: Subwoofer + Kick Bass + 2 Way Passive Front System

-10- -11-
Before you drill or cut any holes, investigate your car's layout very carefully. Take care when you work near
the gas tank, fuel lines, hydraulic lines and electrical wiring.
Do not operate the amplifier when it is not mounted. Attach all audio system components securely within
the automobile to prevent damage, especially in case of an 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 replac e th e power fuse , replac e it only with a fuse identi ca l to th at su pplied with th e sy ste m. Usi ng a fuse of
differe nt typ e or ra ti ng may re su lt in dam ag e to yo ur syste m which isn 't covered by th e man ufactu re r' s war ranty.
Sub Channel: Subwoofer: Low Pass 100 Hz
Channel 1-2-3-4 (Bridged): 2 way system with passive x-over
Channel 1-2: High Pass = 80 Hz
Channel 3-4: Low Pass = Full - High Pass = 80 Hz (must be the same frequency of ch 1-2)
20 100 1 KHz 10 KHz
0 Db
Sub Ch Ch 1-2-3-4
-3 Db
-9 Db
-6 Db
System 4: Subwoofer + Powerfull 2 Way Passive Front System
20 100 1 KHz 10 KHz
0 Db
-3 Db
-9 Db
-6 Db
Sub Channel: Subwoofer: Low Pass 100 Hz
Channel 1-2: Midrange / Tweeter (Tw with passive x-over): High Pass = 800 Hz
Channel 3-4: Mid Bass: Low Pass = 800 Hz - High Pass = 80 Hz
Sub Ch Ch 1-2Ch 3-4
System 5: Subwoofer + Mid Bass + Midrange & Tweeter