A M P L I F I E R S
ENG
INSTALLATION INSTRUCTIONS
General:
Run the wiring so that RCA cables are at least 18“ away from power and
speaker cables. Keep RCA cables away from electrical devices in the vehicle
that can cause electrical noise, such as electric fuel pumps, emission control
modules and other on-board electronic modules.
Power and ground connections:
Use a sufficient gauge power cable and ground cable using the chart below
as reference to what size wire you require. Discus series amplifiers require at
least 1 0 mm
2
power wire. In a multi amplifier system, add the total value of
the manufacture recommended fusing to get your total system amperage.
Some app licat ions may req uire mult iple run s of pow er w ire to meet the sys tem
req uir emen ts. I n mult i amp lif ier sy ste ms it is a dvis abl e to mou nt a lar ge en oug h
fuse right at the battery , and run one or multiple +12 volt power cables to a
fused distribution block near the amplifiers. It is then a simple matter to
connect the +12 volt terminal of each amplifier to the distribution block.
During this process, please ensure that the main power fuse is removed to
avoid shorting the electrical system. The main fuse must be within 30 cm of
the vehicles battery . Ground each amplifier with as short a ground lead as
poss ible di rect ly to the vehi cle cha ssis us ing at leas t 1 0 mm
2
wi re or equi vale nt
to the size of the amplifiers’ power wire. Use a ground distribution block, if
you wish, but it is extr emely impo rtant to k eep t he ma in gr ound lead from this
distribution block to the chassis as short as possible , not more than 30 cm.
The ground connection inte grity to the c hassis is very important, and the best
way to achie ve a go od, solid el ectri cal and mech anica l co ntact is to use a l arge
round crimp lug, crimped and soldered to the ground cable. The next step is
to sc rape th e paint off t he veh icle ch assis , sligh tly lar ger tha n the ground lug,
at the connection point. Drill a cleara nce hole in the chass is, the same size as
the lug hole, and use a bolt, spring washer and nut to securely fasten the
ground lug. Use petroleum jelly to coat the bolt/lug connection, to prevent
oxidization with time.
TIP: Us e t he same ap proac h w hen ins tall ing hea d un its, eq uali zers or an y au dio
equipment for that matter - run short individual grounds from each piece
directly to the vehicle c hassis, to mini mize ground lo ops and system noise. All
power , ground and speaker connections should be crimped and soldered for
reliability . Make sure that none of the cable insulation can chafe against
exposed metal in the vehicle, causing short circuits to the chassis.
Safe connection sequence:
After all cables are run, connect speaker wires to the speakers and amplifiers,
then run and plug in RCA cab les. Next, connect al l power , ground, and r emote
tu rn o n le ad s. N ow c on nec t al l + 12 v olt ca ble s to th e am pli fi er /s a nd d is tri bu tio n
bloc ks and fus e h olde rs. Fin ally , co nnec t t he main +12 vo lt cabl e t o t he batt ery ,
with the m ain f use re moved, and we ar e almo st re ady to powe r up the s ystem.
Power up the system:
The following procedure may seem like overkill, but there is nothing more
frustrating when turning on a system for the first time, and it does not work
properly immediately . First, make sure the head unit is off, and turn all level
controls to minimum (counterclockwise), including the head unit volume
control. Set all equalizers to 0 dB (no boost), and all crossover frequency
controls at approximate frequencies, as recommended by the loudspeaker
manufact urer . Set all input se lector a nd crosso ver switc hes as r equired f or the
appl icati on. Remov e al l amp lifie r fu ses, and inse rt t he m ain fuse at the batte ry .
If the fus e does not b low , you can insert the fuse in one of the a mplifiers, and
we are re ady to tur n o n t he sys tem. T urn th e h ead uni t o n, inse rt a CD, or sel ect
a radi o stat ion, a nd incr eas e t he hea d u nit vo lum e c ontr ol. If t he syst em sou nds
fine, turn off the head unit, and install fuses in the remaining amplifiers, one
by one, till the complete system is powered up and functioning properly .
General:
At t hi s po in t yo u ar e re ad y to get mor e s pec if ic o n th e s ett in gs f or y ou r am pl ifi er .
High Pass:
-When in Hi P ass operation, this setting acts as a low frequency cut off for
your sy stem rep roduction. The po int that you set it at cuts off any fre quencies
from repro ductio n bey ond t his point. The 12 o ’clock posi tion is a great sta rting
point. EXAMPLE: If you adjust the High P ass to 1 00Hz, the amplifier will not
play frequencies below 1 00Hz but will play frequencies from 1 00Hz to the
chosen Low P ass frequency .
-When in Low P ass/Bandpass operation, this setting acts as a low frequency
cut off for your system reproduction aka Subsonic Filter . The point that you
set it at cuts off any frequencies from repr oduction beyond this point. The 12
o’cloc k posit ion is a gre at sta rting p oint. EXAMPLE: If y ou adju st the High P ass
to 25Hz, the amplifier will not play frequencies below 25Hz but will play
frequencies from 25Hz to the chosen Low P ass frequency .
-When in Flat/Full operation, the High P ass crossover is bypassed.
Bass EQ:
This setting is a fixed bass boost at 45Hz that is variable from 0-9dB. This
feature provides impact to your bass, but if not adjusted correctly , it can be
ove r u sed a nd cau se dam age to y our sp eake rs an d a mpl ifie rs. I t i s best t o s low ly
tur n thi s s ett ing c loc kwi se unt il th e desi red p unc h is fel t. It i s not re com men ded
to exceed the 12 o’clock position unless listening at a low volume or a low
recording quality as this can result in high distortion and possibly clipping.
Low Pass:
The Low P ass control acts as a ceiling and doesn’t allow frequencies to the
right of the desired setting to be reproduced. Turning the potentiometer all
the way to the right i s a great starting point. EXA MPLE: If you adjust the Low
P ass to 120Hz, the amplifier will not play frequencies above 120Hz but will
play frequencies from 120Hz to the chosen Hi P ass or Subsonic frequency .
-When in Hi P ass operation, this setting is bypassed.
Level Control Setup:
Ensure that the Level is turned completely to the left prior to turning the
system on. Next you should insert a CD or cassette that you are familiar with
to use as a ref erence, and turn the head unit volume cont rol to about 80% of
its full setting. The system sound level will of course be very low , and the
following procedures will help you to match the amplifier input sensitivities
properly to the head unit output signal level. It is important to match the
amplifier LEVEL input sensitivity to the Radio/CD output sensitivity . This can
be loca ted in the Ra dio/ CD manu al. If the Ra dio/ CD outp ut sens itiv ity is 2 volt s,
then adjust the amplifier LEVEL input to 2 volts.
If you are not sure what the Radio output sensitivity is, follow these
general guide lines:
Turn the level control up slowly , till you hear distortion, then back off a few
degrees on the control . If at any po int you r amplif ier goes into p rotection , you
will need to turn the Level to the left a bit and then try again. If you reach a
point where the output does not increase, stop turning the Level control to
the right as the amplifier/speaker combo has reached its maxx output in this
application.
2 or 3 way active systems (all):
Alw ays s tart w ith t he bas s, or lo w fre que ncy am pli fie r a s a ref eren ce, b y tur ning
its control up to the point where distortion is audible, and back it off some.
Now adjust the level control for the highs or tweeter channels in a 2 way
active system, to balance the highs to lows. In a 3 way active system, match
the midrange level to the bass, and then the highs to the midrange and bass.
It may be necessary to perform a few iterations of the midrange and highs
level control settings to achieve a satisfactory sound balance.
SETTING UP SYSTEMS AFTER
INSTALLATION FOR BEST PERFORMANCE