Rockford Fosgate 125.2 User manual

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car audio
fanatics
for
punc
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2-Channel Amplifiers
Operation & Installation
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Dear Customer,
Congratulations on your purchase of the world's finest brand of car audio amplifiers.
AtRockfordFosgatewearefanaticsaboutmusicalreproductionatitsbest,andweare
pleasedyouchoseourproduct.Throughyearsofengineeringexpertise,handcraftsman-
ship and critical testing procedures, we have created a wide range of products that
reproduce music with all the clarity and richness you deserve.
For maximum performance we recommend you have your new Rockford Fosgate
product installed by an Authorized Rockford Fosgate Dealer, as we provide specialized
training through Rockford Technical Training Institute (RTTI). Please read your
warranty and retain your receipt and original carton for possible future use.
Greatproductandcompetent installationsareonly apieceofthepuzzle whenitcomes
to your system. Make sure that your installer is using 100% authentic installation
accessories from Connecting Punch in your installation. Connecting Punch has
everything from RCA cables and speaker wire to Power line and battery connectors.
Insist on it! After all, your new system deserves nothing but the best.
To add the finishing touch to your new Rockford Fosgate image order your Rockford
wearables,which include everything from T-shirts and jackets tohats and sunglasses.
To get a free brochure on Rockford Fosgate products and Rockford accessories, in the
U.S.call602-967-3565orFAX602-967-8132.Forallothercountries,call+001-602-
967-3565 or FAX [phone].
If, after reading your manual, you still have questions regarding this product,
we recommend that you see your Rockford Fosgate dealer. If you need further
assistance, you can call us direct at 1-800-669-9899. Be sure to have your serial
number, model number and date of purchase available when you call.
PRACTICE SAFE SOUND™
CONTINUOUS EXPOSURE TO SOUND PRESSURE LEVELS OVER 100dB
MAY CAUSE PERMANENT HEARING LOSS.HIGH POWERED AUTOSOUND
SYSTEMS MAY PRODUCE SOUND PRESSURE LEVELS WELL OVER
130dB. USE COMMON SENSE AND PRACTICE SAFE SOUND.
The serial number can be found on the outside of the box. Please record it in
the space provided below as your permanent record. This will serve as
verificationofyourfactorywarrantyandmaybecomeusefulinrecoveringyour
amplifier if it is ever stolen.
Serial Number: ________________________________
Model Number:________________________________

T ABLE OF C ONTENTS
Introduction................................................................................................1
Punch Amplifier Accessory Pack ................................................................... 1
Technical Design Features............................................................................2
Design Features .......................................................................................... 5
Installation Considerations ...........................................................................7
Mounting Location ...................................................................................... 8
Battery and Charging ..................................................................................9
Wiring the System....................................................................................... 9
Using Passive Crossovers........................................................................... 12
Table of Component Values........................................................................ 13
Using the XCard........................................................................................ 14
Resistor Chart ........................................................................................... 15
Installation ...............................................................................................16
System Diagrams...................................................................................... 20
Rockford Fosgate Accessories ..................................................................... 24
Troubleshooting........................................................................................ 26
Dynamic Power Measurements................................................................... 29
Specifications ........................................................................................... 31
Warranty Information ................................................................................ 33
International Information............................................................................34
Sections marked
ADVANCED OPERATION
include in-depth
technical information
Sections marked
TROUBLESHOOTING
include recommendations for
curing installation problems
Sections marked
INSTALLATION
include “slam dunk”
wiring connections
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Welcometo Rockford Fosgate! This manual is designed to provideinformation
for the owner, salesperson and installer. For those of you who want quick
information on how to install this product, please turn to the Installation
Section of this manual or refer to the icons listed below. Other information can
be located by using the Table of Contents. We, at Rockford Fosgate, have
workedveryhardtomakesurealltheinformationinthismanualiscurrent.But,
asweareconstantlyfindingnewwaystoimproveourproduct,thisinformation
is subject to change without notice.
GETTING STARTED
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I NTRODUCTION
Rockford engineers designed the Punch 55.2, 75.2, 125.2and 225.2
amplifierstowithstandtheruggedautomotiveenvironmentwhiledelivering
superiorsoundqualityinaflexible,reliable,andefficientpackage.TRANS•ANA
is a low voltage circuit in the preamp stage of all Punch .2amplifiers that
lets the music sound crystal clear and very real, even when played at high
volumelevels.ThisismatchedwithTOPAZ,auniquegroundingcircuitused
to eliminate noise problems associated with car audio systems and their
installation. Flexibility is accomplished with the use of a built-in XCard.
Reliability is all but guaranteed with the use of a protection circuit called
NOMAD, while MOSFET and DSM (Discrete Surface Mount) technology
improveamplifierefficiency.Theresultof thesecomponentsgive thePunch
amplifier awesome sound quality in a “Bullet Proof” package. An explana-
tion of these technologies, most of which are exclusively designed and
patented by Rockford, are described in the Technical Design Features.
– 1 –
P UNCH A MPLIFIER A CCESSORY P ACK
The accessory pack shipped with the Punch 2-channel amplifiers includes
the mounting hardware necessary to secure the amp to the vehicle and to
attach the end caps to the amplifier.
Installation & Operation Manual
Punch Verification Certificate
(4) Amplifier mounting screws (#8 x 3/4" Phillips)
(6) Speaker & power connector screws (3/32" Allen)
(4) End cap mounting screws (9/64" Allen)
(1) Allen Wrench 9/64"
(1) Allen Wrench 3/32"
(1) ATC Inline Fuseholder (Punch 55.2, 75.2, 125.2)
(1) AGU Inline Fuseholder (Punch 225.2)
(1) ATC 20 Amp Fuse (Punch 55.2)
(1) ATC 30 Amp Fuse (Punch 75.2)
(1) ATC 40 Amp Fuse (Punch 125.2)
(1) AGU 50 Amp Fuse (Punch 225.2)

T ECHNICAL D ESIGN F EATURES
– 2 –
◆TRANS•ANA
(TRANSconductance Active Nodal Amplifier)
The TRANS•ANA (TRANSconductance Active Nodal Amplifier) is a circuit
thatallows the audio signal to passthroughtheamplifier at low voltage. The
signalisdirectly level-shiftedtothefixedhigh voltagerailsviaapair ofdriver
transistors. Signal linearity is assured by an active node formed by the drive
transistors at ultrasonic frequencies. This allows amplifier performance
similar to trans• nova which is highly stable and linear while utilizing the
advantages of a non-floating power supply.
THE RESULT: An extended frequency bandwidth accurately supplied to the
output stages of the amplifier.
◆TOPAZ (Tracking Operation Pre-Amplifier Zone)
The TOPAZ (Tracking Operation Pre-Amplifier Zone) circuitry solves ground
loopnoiseproblemscommontoautomotiveamplifierdesign.Thisinnovative
newdevelopmentallowsvastlyimprovedisolationoftheinputsignalgrounds
from the power supply ground of the amplifier. This is accomplished by
allowing the source unit to control the potential “environment” of the entire
input structure or “zone” of the amplifier. This process improves the noise
rejection of the amplifier by 30-40dB – an astounding 30-100 times better
than amplifiers without TOPAZ.
THE RESULT: Eliminationof troublesome ground loopnoisebetweensource
and amplifier.
◆MEHSA (Maximum Efficiency Heat Sink Application)
The MEHSA (Maximum Efficiency Heat-Sink Application) is a proprietary
process that yields up to 5 times better heat transfer than traditional FET
mounting techniques using the exact same components. A multi-layer
insulatedmetal substrate operatingwithminimal thermalresistancespreads
heat both downward & outward to quickly dissipate heat from each device
across the heat sink. This process combined with our DSM technology and
MOSFET devices allow us to squeeze more watts per cubic inch from every
output device as well as provide consistent thermal stability.
THE RESULT: Optimized power output, enhanced thermal stability, and
maximum component reliability.

◆DSM (Discrete Surface Mount) Technology
The DSM (Discrete Surface Mount) manufacturing process combines the
advantages of both discrete components and integrated circuitry. Rockford
FosgateistheonlyAmericanamplifiermanufacturertohaveinvestedmillions
intothisprocess.DSMcomponentsdifferfromconventionaldiscretecompo-
nents in different ways. They are more compact, more rugged, and they
efficientlydissipate generated heat.Usingthem whereverappropriateallows
the advantages associated with discrete circuitry to be retained while also
providing room for both highly advanced processing features and generous
PC board copper paths where needed. Their short lead-out structures allow
maximum audio performance and highest signal-to-noise ratios to be
obtained in amplifiers of desirable package size without resorting to “ampli-
fier-on-a-chip” shortcuts. These advantages are shown below in Figure 1.
THE RESULT: Fewer connections, improved reliability, shorter signal paths,
superior signal-to-noise ratio and awesome sonic performance.
Figure 1
◆XCard (Internal Crossover)
ThePunchamplifiersutilizeinternalactivecrossovers.Thesecrossovershave
manyperformanceadvantagessuch asusing discretecomponents forexact
frequencyadjustmentswhicharefarsuperiortopotentiometers.Additionally,
the XCard can be configured for high-pass, low-pass and full range
operation. With slight modifications, many crossover frequencies and slope
configurations can be achieved.
THE RESULT: Increased system design flexibility with a precise electronic
crossover without the limitations of conventional potentiometer designs.
– 3 –
Solder Solder
Component
Thru-Hole Surface Mount
PC
Board PC
Board

◆MOSFET Devices
Rockford Fosgate is one of the few manufacturers in the sound community
to utilize MOSFET devices in both the power supply and the output stages .
MOSFET (Metal Oxide Semiconductor Field Effect Transistor) devices offer
severalimportantinherentadvantagesoverthe30yearoldtechnologyofbi-
polar design. These advantages include: thermal stability, switching speed,
ultra low output impedance and wider bandwidth linearity. In addition,
MOSFETsoperateverysimilarly tovacuum tubesin thattheyaremorelinear
thanbi-polartransistors.However,MOSFETscandeliverthemidrangeclarity
without the limitations of transient response and high frequency phase
shifting normally associated with tube operation.
THE RESULT: Operational characteristics similar to vacuum tubes without
the performance limitations of tube design.
◆NOMAD (NOn-Multiplying Advanced Decision)
The Punch amplifiers use an analog computer process to maximize safe
output power under all operating conditions. The innovative NOMAD (NOn-
Multiplying Advanced Decision) system is the most sophisticated version of
thistechniqueeverused,bringingpreviouslyunavailablelevelsofaccuracy,
stability,temperatureimmunityandreliabilitytothiscriticalprocess.NOMAD
makesadvanceddecisionsbasedondevicevoltagesto preciselycontrolthe
awesome levels of current available in the output MOSFETs to safe values –
but only when absolutely needed.
THE RESULT: Extremely fast protection system that always protects the
amplifier and never degrades the sound.
– 4 –
◆Punch EQ
The Punch EQ helps correct for acoustical deficiencies in the listening
environment. Two unique potentiometers that control bass and treble
compensatefortheresponseerrorspresentinmostcarenvironments.Unlike
conventionaltonecontrols,PunchEQcorrectsthespecificproblemsofpoor
low bass response and high frequency rolloff.
THE RESULT: Full range sound without excessive boost in areas where it is
not needed.

D ESIGN F EATURES
1. Cast Aluminum Heatsink – The cast aluminum heatsink of the Punch
amplifier dissipates heat generated by the amplifier's circuitry. The
inherentadvantageof casting provides a 30% improvement of cooling
over conventional extrusion heatsink designs.
2. End Caps – The unique end caps conceal the wiring and input cables,
giving the amplifier a clean “stealth” look.
+R–+L– Bass
Right
Gain
Right
Input
Left
Input
Left
Gain
Treble
Speaker Speaker
3 8 7 7
6 6 83
3. Speaker Terminals – The heavy duty, gold-plated terminal block
connectors (+ and –) will accept wire sizes from 8 AWG to 18 AWG.
These gold-plated connectors are immune to corrosion that can cause
signal deterioration.
4. Power Terminals – The power and ground connectors on the Punch
amplifier are gold-plated and will accommodate up to 8 AWG wire
maximizing the input current capability of the amplifier.
5. REM Terminal – This gold-plated spade terminal is used for the auto
power/remote turn on of the Punch amplifier.
6. RCA Input Jacks – The industry standard RCA jacks provide easy
connections for signal level input. They are gold-plated to resist the
signal degradation caused by corrosion.
49 5
GNDB+
LED
REM
– 5 –

7. Input Sensitivity Controls – The input level controls are preset to
matchtheoutputofmostsourceunits.They canbeadjustedtomatch
output levels from a variety of source units.
8. Punch Equalization Controls – The Punch EQ helps correct for
acoustical deficiencies in the listening environment. The Bass control
allowsanarrowbandadjustmentofupto18dBcenteredat45Hz.The
Treble control is a wide band hinged adjustment with a maximum of
12dB at 20kHz. The Punch EQ can be bypassed by turning the
controls to their minimum or counterclockwise position.
9. LEDPowerIndicator–TheLEDilluminateswhentheunitisturnedon.
10. XCard (Internal Crossover) – This built-in crossover card is
configurable for a multitude of operating frequencies. The orientation
ofthecardinitssocketdeterminesthefunctionofhigh-pass,low-pass,
or full range operation.
– 6 –
HP
LP
HP
LP
FULL
For Bridged Mono Wiring
Connect 4Ωmono woofer + to L+ of amplifier
and mono woofer – to R– of amplifier. Amplifier
will operate mono/stereo simultaneously.
ROCKFORD CORPORATION
MADE IN THE USA
®
®
27.5 Watts RMS continuous power per
channel into 4 Ohms with less than 0.08%
Total Harmonic Distortion from 20-20kHz
AMPLIFIER
Do Not Chassis
Ground Any Speaker.
+–
L+ R–
Low-Pass
Full Range
High-Pass
10

I NSTALLATION C ONSIDERATIONS
Thefollowingis alistoftoolsyou willneedforinstallingthe Punchamplifier:
Allen wrenches 9/64" & 3/32" (included) Voltmeter
Wire strippers Battery post wrench
Electric hand drill w/assorted bits Wire cutters
17' (518.16cm) Red Power Wire Assorted connectors
12' (365.76cm) Remote Turn-On Wire Wire crimpers
1.5' (45.72cm) Black Grounding Wire
– 7 –
Thissectionfocusesonsomeofthevehicleconsiderationsforinstallingyour
new Punch amplifier. Checking your battery and present sound system, as
well as pre-planning your system layout and best wiring routes will save
installationtime. Whendecidinghowtolayoutyournewsystem,besurethat
each component will be easily accessible for making adjustments.
Before beginning any installation, be sure to follow these simple rules:
1. Besuretocarefullyreadandunderstandtheinstructionsbeforeattempt-
ing to install the amplifier.
2. For safety, disconnect the negative lead from the battery prior to
beginning the installation.
3. Foreasierassembly,wesuggestyourunallwirespriortomountingyour
amplifier in place.
4. Route all of the RCA cables close together and away from any high
current wires.
5. Use high quality connectors for a reliable installation and to minimize
signal or power loss.
6. Think before you drill! Be careful not to cut or drill into gas tanks, fuel
lines, brake or hydraulic lines, vacuum lines or electrical wiring when
working on any vehicle.
7. Never run wires underneath the vehicle. Running the wires inside the
vehicle provides the best protection.
8. Avoid running wires over or through sharp edges. Use rubber or plastic
grommets to protect any wires routed through metal, especially the
firewall.
9. ALWAYS protect the battery and electrical system from damage with
proper fusing. Install a fuseholder and appropriate fuse on the +12V
power wire within 18” (45.7 cm) of the battery terminal.
10. When grounding to the chassis of the vehicle, scrape all paint from the
metal to ensure a good, clean ground connection. Grounding connec-
tions should be as short as possible and always be connected to metal
that is welded to the main body, or chassis, of the vehicle.

M OUNTING L OCATION
Themountinglocationandpositionof youramplifierwill haveagreateffect
on its ability to dissipate the heat generated during normal operation. The
design of our cast aluminum heatsink serves to easily dissipate the heat
generatedoverawiderangeofoperatingconditions.However,tomaximize
theperformance ofyouramplifier, careshouldbe taken toensure adequate
ventilation.
Trunk Mounting
Mounting the amplifier vertically on a surface with the fin grooves running
up and down will provide the best cooling of the amplifier.
Mounting the amplifier on the floor of the trunk will work but provides less
cooling capability than vertical mounting.
Mounting the amplifier upside down to the rear deck of the trunk will not
provide proper cooling and will severely affect the performance of the
amplifier and is strongly not recommended.
Passenger Compartment Mounting
Mounting the amplifier in the passenger compartment will work as long as
you provide a sufficient amount of air for the amplifier to cool itself. If you
aregoingtomounttheamplifierundertheseatofthevehicle,youmusthave
at least 1" (2.54cm) of air gap around the amplifier's heatsink.
Mounting the amplifier with less than 1" (2.54cm) of air gap around the
amplifier's heatsink in the passenger compartment will not provide proper
cooling and will severely affect the performance of the amplifier and is
strongly not recommended.
Engine Compartment Mounting
Rockford Fosgate amplifiers should never be mounted in the engine
compartment. Not only will this void your warranty but could create an
embarrassing situation caused by the ridicule from your friends.
– 8 –

B ATTERY AND C HARGING
– 9 –
Amplifiers will put an increased load on the vehicle's battery and charging
system. We recommend checking your alternator and battery condition to
ensure that the electrical system has enough capacity to handle the
increased load of your stereo system. Stock electrical systems which are in
good condition should be able to handle the extra load of any Rockford
amplifier without problems, although battery and alternator life can be
reduced slightly. To maximize the performance of your Rockford Fosgate
amplifier,wesuggesttheuseofaheavydutybatteryandanenergystorage
capacitor.
W IRING THE S YSTEM
CAUTION: Avoid running power wires near the low level input cables,
antenna, power leads, sensitive equipment or harnesses. The power
wires carry substantial current and could induce noise into the audio
system.
•Forsafety,disconnectthenegativeleadfromthebatterypriortobeginning
the installation.
1. Configure the internal XCard crossovers prior to installation. Refer to
“Using the XCard” (page 14) for further information.
2. Plan the wire routing. Take care when running signal level RCA cables
tokeepthemclosetogetherbutisolatedfromtheamplifier'spowercables
and any high power auto accessories, especially electric motors. This is
doneto prevent couplingthenoise from radiated electricalfieldsinto the
audio signal. When feeding the wires through the firewall or any metal
barrier, protect them with plastic or rubber grommets to prevent short
circuits. Leave the wires long at this point to adjust for a precise fit at a
later time.
3. Prepare the Power cable for attach-
menttotheamplifierbystripping5/8"
ofinsulationfromthe end of the wire.
Toprevent the wire from fraying, strip
the insulation at a 45°angle. Insert
the bared wire into the B+ terminal
withthe longsideof theinsulation on
thetop.Bendthecabledownata90°
angle.Tightenthesetscrew tosecure
the cable in place.
><
5/8"
INSULATION
STRIP WIRE
>
>
AMP
>

– 10 –
Punch 55.2, 75.2, 125.2
Trimthepowercabletowithin18" ofthebattery andinstalltheprotective
rubberboot,whichispackedwiththefuseholder,overtheendofthewire.
Strip 3/8" of insulation from the wire and insert into the end of the
fuseholder,thencrimpitinplace.Slidetherubberbootintoplacetocover
the connection. Use the section of cable that was trimmed earlier and
connect it to the other end of the fuseholder.
Punch 225.2
Mount the fuseholder within 18" of the battery using two (2) #8 screws.
Disassemble the fuseholder. You should have 2 black plastic end caps,
2 gold-plated fuse clips, a plastic spacer and the fuseholder body. Trim
the amplifier power cable to reach the fuseholder and strip the wire 3/8".
Slide one of the end caps over the wire (narrow end first) and insert the
wire into one of the fuse clips. Tighten the set screw. Screw the black end
cap to the fuseholder body to secure the cable. Use the section of cable
thatwastrimmedearlierandconnectit totheother endofthefuseholder.
Install the plastic spacer in the fuseholder and attach the cable to the
fuseholder body.
NOTE: The B+ cable MUST be fused 18" or less from the vehicle's
battery. Install the fuseholder under the hood and prepare the cable
ends as stated above. Connections should be water tight.
4. Strip 3/8" from the battery end of the power cable and crimp a large ring
terminal to the cable. Use the ring terminal to connect to the battery
positive terminal. Do not install the fuse at this time.
5. Prepare a length of cable to be used for the ground connection. Strip
5/8" of insulation from the end of the cable as described previously
and connect to the appropriate terminal of the amplifier. Prepare the
chassis ground by scraping any paint from the metal surface and
thoroughly clean the area of all dirt and grease. Strip the other end of the
wire and attach a ring connector. Fasten the cable to the chassis using a
non-anodized screw and a star washer.
6. PreparetheREM turn-onwireforconnectiontotheamplifierbystripping
1/4" of insulation from the wire end and crimping an insulated spade
connector in place. Slide the connector over the REM terminal on the

amplifier. Connect the other end of the REM wire to a switched 12 volt
positive source. The switched signal is usually taken from the source
unit'sautoantennaortheaccessorylead.Ifthesourceunitdoesnothave
theseoutputsavailable,therecommendedsolutionistowireamechani-
cal switch in line with a 12 volt source to activate the amplifier.
7. Securely mount the amplifier (with supplied screws) to the vehicle or
amp rack. Be careful not to mount the amplifier on cardboard or plastic
panels. Doing so may enable the screws to pull out from the panel due
to road vibration or sudden vehicle stops.
8. Connect the source signal to the amplifier by plugging the RCA cables
into the input jacks at the amplifier.
9. Connectthe speakers. Strip the speaker wires 5/8". Insert thebared wire
into the speaker terminal and tighten the set screw to secure into place.
Be sure to maintain proper speaker polarity. DO NOT chassis ground
any of the speaker leads as unstable operation may result.
10. Perform a final check of the completed system wiring to ensure that all
connections are accurate. Check all power and ground connections for
frayed wires and loose connections which could cause problems.
11. After the final inspection is complete, install the power fuse and enjoy
listening. During the initial listening period, you may need to “fine tune”
any phasing and level settings within your particular vehicle. To aid in
thisprocedure,playatrackwithhighmusicalcontentandcruisearound
your neighborhood. After fully evaluating the transient response of your
system and making any final adjustments, all your neighbors within a
1 mile radius will assume that you have just successfully completed
another upgrade to your audio system for which they will probably spill
thumbtacks on your driveway.
– 11 –

U SING P ASSIVE C ROSSOVERS
Apassivecrossoverisacircuitthatusescapacitorsand/orcoilsandisplaced
onspeakerleadsbetweentheamplifierandspeaker.Thecrossoverdelegates
aspecificrangeoffrequenciestothespeakerforoptimumdriverperformance.
A crossover network can perform one of three functions: High-Pass (capaci-
tors),Low-Pass(inductorsorcoils)andBandpass(combinationofcapacitor
and coil).
The most commonly used passive crossover networks are 6dB/octave
systems. These are easy to construct and require one component per filter.
Placing this filter in series with the circuit will reduce power to the speaker by
6dB/octave above or below the crossover point depending on whether it is a
high-pass or low-pass filter. More complex systems such as 12dB/octave or
18dB/octavecancause impedance problems if not professionally designed.
Passivecrossoversaredirectlydependentuponthespeaker'simpedanceand
component value for accuracy. When passive crossover components are
used in multiple speaker systems, the crossover's effect on the overall
impedance should be taken into consideration along with the speaker's
impedancewhendeterminingamplifierloads. CAUTION: The Punch ampli-
fiersarenotrecommendedforimpedanceloadsbelow2Ωstereoand4Ω
bridged (mono) loads.
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T ABLE OF C ROSSOVER C OMPONENT V ALUES
6dB/Octave Low-Pass 6dB/Octave High-Pass
Freq.
Hertz Speaker Impedance
80 4.1mH 1000µF 8.2mH 500µF 16mH 250µF
100 3.1mH 800µF 6.2mH 400µF 12mH 200µF
130 2.4mH 600µF 4.7mH 300µF 10mH 150µF
200 1.6mH 400µF 3.3mH 200µF 6.8mH 100µF
260 1.2mH 300µF 2.4mH 150µF 4.7mH 75µF
400 .8mH 200µF 1.6mH 100µF 3.3mH 50µF
600 .5mH 136µF 1.0mH 68µF 2.0mH 33µF
800 .41mH 100µF .82mH 50µF 1.6mH 26µF
1000 .31mH 78µF .62mH 39µF 1.2mH 20µF
1200 .25mH 66µF .51mH 33µF 1.0mH 16µF
1800 .16mH 44µF .33mH 22µF .68mH 10µF
4000 .08mH 20µF .16mH 10µF .33mH 5µF
6000 51µH14µF .10mH 6.8µF .20mH 3.3µF
9000 34µH 9.5µF68µH 4.7µF .15mH 2.2µF
12000 25µH 6.6µF51µH 3.3µF 100µH 1.6µF
2 OHMS 8 OHMS
4 OHMS
LC L CL C
LC
L = Low-Pass (Inductor)
C = High-Pass (Capacitor)
For more information, see your Authorized Rockford Fosgate Dealer.
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– 14 –
3386
fo= R (in kΩ) for .047µf cap
= R(in kΩ) for .022µf cap
7234
fo
Where: R = Ω
fo= desired crossover frequency
c = capacitor in farads
ex: .047 x 10-6 for .047µf cap
Crossover Card
High Pass
Low Pass
Full Range
R1 R2 R1 R2
FULL
Thecrossoverpointcanbealteredbychangingall4resistorvalues.Usethefollowing
formula to select the appropriate resistor value to be placed on the XCard.
U SING THE XC ARD
1
2πfoc
The actual formula is:
R =
Low-Pass Full RangeHigh-Pass
FULL
↕
HP
➝
➝
LP
HP
➝
➝
LP
The crossover functions are controlled through the use of an XCard and can
besetforhigh-pass,low-passorfullrangeoperation.TheXCardshippedwith
your amplifier is set for Full Range. Each crossover card has two faces: one
face operates Full Range, the other has arrows to indicate the edge for
selectingHP(high-pass)orLP(low-pass)operation.Orientthecardwiththe
desired operating edge, indicated by the arrow, toward the socket terminals
inside the amplifier. Firmly, but carefully, plug the card into the socket.
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R ESISTOR C HART
– 15 –
Frequency R1 R2
20Hz 169kΩ169kΩ
25Hz 133kΩ133kΩ
30Hz 110kΩ110kΩ
35Hz 95.3kΩ95.3kΩ
40Hz 84.5kΩ84.5kΩ
45Hz 75kΩ75kΩ
50Hz 68.1kΩ68.1kΩ
55Hz 61.9kΩ61.9kΩ
60Hz 56.2kΩ56.2kΩ
65Hz 52.3kΩ52.3kΩ
70Hz 48.7kΩ48.7kΩ
75Hz 45.3kΩ45.3kΩ
80Hz 42.2kΩ42.2kΩ
85Hz 40.2kΩ40.2kΩ
90Hz 37.4kΩ37.4kΩ
200Hz 16.9kΩ16.9kΩ
300Hz 11.3kΩ11.3kΩ
400Hz 8.45kΩ8.45kΩ
500Hz 6.65kΩ6.65kΩ
600Hz 5.62kΩ5.62kΩ
700Hz 4.75kΩ4.75kΩ
800Hz 4.22kΩ4.22kΩ
900Hz 3.74kΩ3.74kΩ
1kHz 3.40kΩ3.40kΩ
1.2kHz 2.80kΩ2.80kΩ
2kHz 1.69kΩ1.69kΩ
3kHz 1.10kΩ1.10kΩ
4kHz 845Ω845Ω
5kHz 665Ω665Ω
6kHz 562Ω562Ω
7kHz 487Ω487Ω
8kHz 422Ω422Ω
Butterworth Alignment Q = .707
1% resistors used with 0.047µF caps Butterworth Alignment Q = .707 1% resistors used with 0.022µF caps
Ourtestshaveshownthatusing0.047µfcapacitorsforfrequenciesbelow100Hz,and0.022µf
capacitors for frequencies above 100Hz, result in more linear crossover control. Refer to the
Specifications page to determine the capacitor value of each supplied XCard.
a
d
v
a
n
c
e
d
O
p
e
r
a
t
i
o
n
Frequency R1 R2
20Hz 357kΩ357kΩ
25Hz 287kΩ287kΩ
30Hz 237kΩ237kΩ
35Hz 205kΩ205kΩ
40Hz 178kΩ178kΩ
45Hz 162kΩ162kΩ
50Hz 143kΩ143kΩ
55Hz 130kΩ130kΩ
60Hz 121kΩ121kΩ
65Hz 110kΩ110kΩ
70Hz 102kΩ102kΩ
75Hz 95.3kΩ95.3kΩ
80Hz 90.9kΩ90.9kΩ
85Hz 84.5kΩ84.5kΩ
90Hz 80.6kΩ80.6kΩ
200Hz 35.7kΩ35.7kΩ
300Hz 23.7kΩ23.7kΩ
400Hz 17.8kΩ17.8kΩ
500Hz 14.3kΩ14.3kΩ
600Hz 12.1kΩ12.1kΩ
700Hz 10.2kΩ10.2kΩ
800Hz 9.9kΩ9.9kΩ
900Hz 8.6kΩ8.6kΩ
1.0kHz 7.15kΩ7.15kΩ
1.2kHz 6.04kΩ6.04kΩ
2.0kHz 3.57kΩ3.57kΩ
3.0kHz 2.37kΩ2.37kΩ
4.0kHz 1.76kΩ1.76kΩ
5.0kHz 1.43kΩ1.43kΩ
6.0kHz 1.21kΩ1.21kΩ
7.0kHz 1.02kΩ1.02kΩ
8.0kHz 909Ω909Ω

– 16 –
I NSTALLATION
*Keep grounds as short as possible
Power Connections
I
N
S
T
A
L
L
A
T
I
O
N
® ®
LED
Connect to remote
turn-on lead of
source unit
Connect to chassis
ground of vehicle*
Connect to B+ of battery with
appropriate fuse value
Less than 18"
GNDB+
P55
.
2
P75
.2
P125
.2
P225.
2
- 20A
- 30A
- 40A
- 50A
REM

– 17 –
I
N
S
T
A
L
L
A
T
I
O
N
® ®
Stereo Operation
Bass
Right
Gain
Right
Input
Left
Input
Left
Gain
Treble
–
+
+L–
Speaker +R– Speaker
–
+
RCA Input
2Ωmin.
2Ωmin.
•RCA inputs are connected to both left and right channels
•Gain for left and right channels operate independently
•Impedance for each channel should be 2Ωminimum
•XCard can be set for High-Pass, Low-Pass or Full Range