250M
Installation &
Operation
Mono Amplifier
Installation et fonctionnement
Instalación y funcionamiento
Einbau und Betrieb
Installazione e funzionamento
GETTING STARTED
Welcome
to
Rockford
Fosgate!
This
manual
is
designed
to
provide
information 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. Other
information can be located by using the Table of Contents. We, at Rockford Fosgate, have worked
very hard to make sure all the information in this manual is current. But, as we are constantly
finding new ways to improve our product, this information is subject to change without notice.
SAFETY INSTRUCTIONS
This symbol with “WARNING” is intended to alert the user to the
presence of important instructions. Failure to heed the
instructions will result in severe injury or death.
This symbol with “CAUTION” is intended to alert the user to the
presence of important instructions. Failure to heed the
instructions can result in injury or unit damage.
CAUTION: To prevent injury and damage to the unit, please read and follow the
!
instructions in this manual. We want you to have enjoyment from this
system, not a headache.
CAUTION If you feel unsure about installing this system yourself, have it installed
!
!
by a qualified Rockford Fosgate technician.
CAUTION Before installation, disconnect the battery negative (-) terminal to
prevent damage to the unit, fire and/or possible injury.
CONTENTS OF CARTON
Model 250M Mono Amplifier
Installation & Operation Manual
Mounting Hardware Kit
Remote Punch Bass Kit with Cord
1 3/32" Allen Wrench
1 9/64" Allen Wrench
1 Fuse Connector
High Level Input Harness
(replacement part # CC-1992)
1 20 Amp Fuse
The hardware kit included with each amplifier contains the mounting hardware necessary to secure
the amplifier to the vehicle and to attach the end caps to the amplifier.
Visit our web site for the latest information on all Rockford products.
3
DESIGN FEATURES
1. Cast Aluminum Heatsink – The cast aluminum heatsink of the Power amplifier dissipates heat
generated by the amplifier's circuitry. The inherent advantage of casting provides a 30%
improvement of cooling over conventional extrusion heatsink designs.
2. Gain Control – The input gain control is preset to match the output of most source units. It can
be adjusted to match output levels from a variety of source units.
3. Variable Crossover – The amplifiers have a built-in 24dB/octave Butterworth filter with a
crossover point variable from 50Hz to 250Hz. The crossover can be set to Low-Pass (LP) or it
can be bypassed by setting it to All Pass (AP).
4. RCA Input Jacks – The industry standard RCA jacks provide an easy connection for signal level
input. They are gold-plated to resist the signal degradation caused by corrosion.
5. LED Power Indicator – The LED illuminates when the unit is turned on.
6. REM Terminal – This spade terminal is used to remotely turn-on and turn-off the amplifier when
+12V DC is applied.
7. Power Terminals – The power and ground connectors on the Power amplifier are gold-plated
and will accommodate up to 8 AWG wire maximizing the input current capability of the
amplifier.
8. Punch Bass – The Punch Bass control helps correct for acoustical deficiencies in the listening
environment by helping produce full range sound without adding excessive boost.. The Punch
Bass control is a narrow band adjustment at 45Hz variable from 0dB to + 18dB. Connection is
made with a cable using RJ-45 and can be installed under the dash for remote control access.
9. RCA Pass-Thru Jacks – The Pass-Thru provides a convenient source for daisy-chaining an
additional amplifier without running an extra set of RCA cables from the front of the vehicle to
the rear amplifier location.
10. 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.
INSTALLATION
INSTALLATION CONSIDERATIONS
The following is a list of tools needed for installation:
Volt/Ohm Meter
Wire strippers
Hand held drill w/assorted bits
1/8" diameter heatshrink tubing
Assorted connectors
Wire crimpers
Wire cutters
Adequate Length—Red Power Wire
Adequate Length—Remote Turn-on Wire
Adequate Length—Black Grounding Wire
#2 Phillips screwdriver
Battery post wrench
4
INSTALLATION
This section focuses on some of the vehicle considerations for installing your new Amplifier. Pre-
planning your system layout and best wiring routes will save installation time. When deciding on
the layout of your new system, be sure that each component will be easily accessible for making
adjustments.
CAUTION: If you feel unsure about installing this system yourself, have it installed
!
by a qualified technician.
CAUTION: Before installation, disconnect the battery negative (-) terminal to
!
prevent damage to the unit, fire and/or possible injury.
Before beginning any installation, follow these simple rules:
1. Be sure to carefully read and understand the instructions before attempting to install the Unit.
2. For safety, disconnect the negative lead from the battery prior to beginning the installation.
3. For easier assembly, we suggest you run all wires prior to mounting your Source Unit 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 the
appropriate fuse holder and 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 connections should be as short as possible and always be
connected to metal that is welded to the main body, or chassis, of the vehicle.
MOUNTING LOCATIONS
The mounting position of your amplified subwoofer will have a great effect on the sound
performance produced.
Engine Compartment
Never mount this unit in the engine compartment. Mounting the unit in the engine compartment
will void your warranty.
Trunk Mounting
Mounting the amplifier vertically 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 are going to mount the amplifier under the seat
of the vehicle, you must have 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.
5
INSTALLATION
BATTERY AND CHARGING
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 Fosgate amplifier without
problems, although battery and alternator life can be reduced slightly. To maximize the performance
of your amplifier, we suggest the use of a heavy duty battery and an energy storage capacitor.
WIRING THE SYSTEM
CAUTION: If you do not feel comfortable with wiring your new unit, please see
!
your local Authorized Rockford Fosgate Dealer for installation.
CAUTION: Before installation, disconnect the battery negative (-) terminal to
!
prevent damage to the unit, fire and/or possible injury.
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.
1. Plan the wire routing. Keep RCA cables close together but isolated from the amplifier's power
cables and any high power auto accessories, especially electric motors. This is done to prevent
coupling the noise from radiated electrical fields into 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.
2. Prepare the RED wire (power cable) for attachment to the amplifier by stripping 1/2" of
insulation from the end of the wire. Insert the bared wire into the B+ terminal and tighten the set
screw to secure the cable in place.
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.
3. Trim the RED wire (power cable) within 18" of the battery and strip1/2"of insulation from the
end of the wire. Cut the wire loop that is attached to the fuseholder in half and splice the fuse
into the power line using appropriate inline connectors. Use the section of cable that was
trimmed earlier and connect it to the other end of the fuseholder.
4. Strip 1/2" 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 the BLACK wire (Ground cable) for attachment to the amplifier by stripping 1/2" of
insulation from the end of the wire. Insert the bared wire into the GND terminal and tighten the
set screw to secure the cable in place. 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. Prepare the REM turn-on wire for connection to the amplifier by stripping 1/2" of insulation from
the wire end. Insert the bared wire into the REM terminal and tighten the set screw to secure the
cable into place. Connect the other end of the REM wire to a switched 12 volt positive source.
The switched voltage is usually taken from the source unit's accessory lead. If the source unit
does not have this output available, the recommended solution is to wire a mechanical switch
in line with a 12 volt source to activate the amplifier.
7. Securely mount the amplifier 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/high level inputs into the
input jacks at the amplifier.
9. Connect the speakers. Strip the speaker wires 1/2" and insert 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.
6
INSTALLATION
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.
NOTE: Follow the diagrams for proper signal polarity.
CAUTION: These amplifiers are not recommended for impedance loads below 2Ω.
!
USING PASSIVE CROSSOVERS
A passive crossover is a circuit that
uses capacitors and/or coils and is
placed on speaker leads between the
amplifier and speaker. The crossover
delegates a specific range of
frequencies to the speaker for optimum
driver performance. A crossover
network can perform one of three
functions: High-Pass (capacitors), Low-
Pass (inductors or coils) and Bandpass
(combination of capacitor and coil).
C
L
6dB/Octave Low-Pass
6dB/Octave High-Pass
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/octave can cause
impedance problems if not
Speaker Impedance
Freq.
Hertz
2 OHMS
4 OHMS
8 OHMS
L
C
L
C
L
C
80 4.1mH 1000mF 8.2mH 500mF 16mH 250mF
100 3.1mH 800mF 6.2mH 400mF 12mH 200mF
130 2.4mH 600mF 4.7mH 300mF 10mH 150mF
200 1.6mH 400mF 3.3mH 200mF 6.8mH 100mF
260 1.2mH 300mF 2.4mH 150mF 4.7mH
75mF
50mF
professionally designed.
400
600
.8mH 200mF 1.6mH 100mF 3.3mH
Passive crossovers are directly
dependent upon the speaker's
.5mH 136mF 1.0mH
800 .41mH 100mF .82mH
68mF 2.0mH
50mF 1.6mH
39mF 1.2mH
33mF
26mF
20mF
impedance and 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 impedance when
1000 .31mH
78mF .62mH
1200 .25mH
1800 .16mH
4000 .08mH
66mF .51mH
44mF .33mH
20mF .16mH
33mF 1.0mH
22mF .68mH
10mF .33mH
16mF
10mF
5mF
6000 51mH
14mF .10mH
9000 34mH 9.5mF 68mH
12000 25mH 6.6mF 51mH
6.8mF .20mH 3.3mF
4.7mF .15mH 2.2mF
3.3mF 100mH 1.6mF
determining amplifier loads.
CAUTION: These amplifiers
!
are not
L = Low-Pass (Inductor)
recommended for
impedance loads
below 2Ω.
C = High-Pass (Capacitor)
For more information, see your Authorized Rockford
Fosgate Dealer.
7
INSTALLATION
REMOTE PUNCH BASS
Mounting
Clip
Mounting and installation
1. Find a location, either under the dash or
near the center console, that gives easy
access to the remote.
2. Using the screws supplied, install the
mounting clip with the tabs towards t
he back.
3. Route the cable for the remote and
connect to both the remote and
amplifed subwoofer.
4. Slip the remote onto the mounting clip
until it snaps into place.
Knob
5. Install the decal and knob onto the
remote.
Decal
OPERATION
ADJUSTING GAIN
To adjust the gain setting, turn the amplifier gains all the way down. Turn the source unit volume up
until distortion is audible and then turn it down a bit until the distortion is inaudible. This will be
about two thirds all the way up on most source units. Next, turn the amplifier gain setting until once
again distortion is audible and then back it down until the distortion is inaudible. Rockford Fosgate
source units do not distort, so the volume can be used at maximum setting.
NOTE: For a more in depth setting procedure, contact Rockford Technical Support.
ADJUSTING CROSSOVER FREQUENCY
Placing the switch in the AP position sets the amplifier to the all pass frequency mode, preventing
any crossover adjustment.
Placing the switch in the LP position allows the crossover frequency to be adjusted between
50-250Hz.
Turn the crossover adjustment knob all the way down. With the system playing, turn the crossover
adjustment knob up slowly until the desired crossover point is achieved.
8
TROUBLESHOOTING
NOTE: If you are having problems after installation follow the Troubleshooting procedures below.
Procedure 1: Check Amplifier for proper connections.
Verify that POWER light is on. If POWER light is on skip to Step 2, if not continue.
1. Check in-line fuse on battery positive cable. Replace if necessary.
2. Verify that Ground connection is connected to clean metal of the vehicle’s chassis.
Repair/replace if necessary.
3. Verify there is 10.5 - 15.5 Volts of current present at the positive battery and remote turn-on
cable. Verify quality connections for both cables at amplifier, stereo, and battery/fuseholder.
Repair/replace if necessary.
Procedure 2: Check Amplifier for audio output.
1. Verify good RCA/high-level input connections at stereo and amplifier. Check entire length of
cables for kinks, splices, etc. Test RCA/high-level inputs for AC current with stereo on.
Repair/replace if necessary.
2. Disconnect RCA/high-level input from amplifier. Connect RCA/high-level input from test stereo
directly to amplifier input.
Procedure 3: Check Amplifier if you experience Turn-on Pop.
1. Disconnect input signal to amplifier and turn amplifier on and off.
2. If the noise is eliminated, connect the REM lead of amplifier to source unit with a delay turn-on
module.
OR
1. Use a different 12 Volt source for REM lead of amplifier (i.e. battery direct).
2. If the noise is eliminated, use a relay to isolate the amplifier from noisy turn-on output.
Procedure 4: Check Amplifier if you experience excess Engine Noise.
1. Route all signal carrying wires (RCA, Speaker cables) away from power and ground wires.
OR
2. Bypass any and all electrical components between the stereo and the amplifier(s). Connect
stereo directly to input of amplifier. If noise goes away the unit being bypassed is the cause of
the noise.
OR
3. Remove existing ground wires for all electrical components. Reground wires to different
locations. Verify that grounding location is clean, shiny metal free of paint, rust etc.
OR
4. Add secondary ground cable from negative battery terminal to the chassis metal or engine block
of vehicle.
OR
5. Have alternator and battery load tested by your mechanic. Verify good working order of vehicle
electrical system including distributor, spark plugs, spark plug wires, voltage regulator etc.
ACCESSORIES
Connecting PUNCH Capacitors
Maintain the power you need to your Power Amplifier.
Connecting Links
Mount your Power Amplifiers together for space reduction and a smooth look.
See our website for other accessories to help you get the most out of your system.
9
SPECIFICATIONS
MODEL
POWER 250M
Continuous Power Rating (RMS) - Measured at 14.4 Battery Volts
4Ω Load Mono
125 Watts
250 Watts
2Ω Load Mono
Signal-to-Noise Ratio
Crossover Slope
>100dB A-weighted
24dB/octave Butterworth
variable from 50Hz to 250Hz
Crossover Frequency
Dimensions: (with Endbell)
Height
Width
Length
2.60" (6.60cm)
9.8" (24.89cm)
11.35 (28.83cm)
Frequency Response
20Hz to 20kHz 0.5dB
10Hz to 200kHz 3dB
>200
Bandwidth
Damping Factor @ 4Ω (at output connector )
Slew Rate
30 Volts/ms
IM Distortion (IHF)
<0.05%
Source Unit Compatibility (+15dB gain overlap)
Acceptable Signal Voltage Range
17V max. (low level in)
Variable from 250mV to 6V (RCA)
Protection
NOMAD - Internal analog-computer output protection
circuitry limits power in case of overload. Thermal
switch shuts down the amplifier in case of overheating.
Battery Fusing Rates (External to Amplifier)
Fuse Type
15 amps
ATC
Variable from 0dB to +18dB @ 45Hz
20k ohms
Equalization (45Hz Punch Bass)
Input Impedance
Specifications subject to change without notice
10
LIMITED WARRANTY INFORMATION
Rockford Corporation offers a limited warranty on Rockford Fosgate products on the
following terms:
Length of Warranty
PUNCH Amplifiers – 2 years
All Other Amplifier Models – 3 years
Source Units – 1 year
Speakers – 1 year
90 days on speaker, amplifier and source unit B-stock (receipt required)
What is Covered
This warranty applies only to Rockford Fosgate products sold to consumers by Authorized
Rockford Fosgate Dealers in the United States of America or its possessions. Product
purchased by consumers from an Authorized Rockford Fosgate Dealer in another country
are covered only by that country’s Distributor and not by Rockford Corporation.
Who is Covered
This warranty covers only the original purchaser of Rockford product purchased from an
Authorized Rockford Fosgate Dealer in the United States. In order to receive service, the
purchaser must provide Rockford with a copy of the receipt stating the customer name,
dealer name, product purchased and date of purchase.
Products found to be defective during the warranty period will be repaired or replaced
(with a product deemed to be equivalent) at Rockford's discretion.
What is Not Covered
1. Damage caused by accident, abuse, improper operations, water, theft
2. Any cost or expense related to the removal or reinstallation of product
3. Service performed by anyone other than Rockford or an Authorized Rockford Fosgate
Service Center
4. Any product which has had the serial number defaced, altered, or removed
5. Subsequent damage to other components
6. Any product purchased outside the U.S.
7. Any product not purchased from an Authorized Rockford Fosgate Dealer
Limit on Implied Warranties
Any implied warranties including warranties of fitness for use and merchantability are
limited in duration to the period of the express warranty set forth above. Some states do not
allow limitations on the length of an implied warranty, so this limitation may not apply. No
person is authorized to assume for Rockford Fosgate any other liability in connection with
the sale of the product.
How to Obtain Service
Please call 1-800-669-9899 for Rockford Customer Service. You must obtain an RA#
(Return Authorization number) to return any product to Rockford Fosgate. You are
responsible for shipment of product to Rockford.
Ship to: Electronics
Ship to: Speakers
Rockford Corporation
Warranty Repair Department
2055 E. 5th Street
Rockford Acoustic Design
Speaker Returns
2356 Turner Ave. NW
Grand Rapids, MI 49544
RA#: ____________________
Tempe, AZ 85281
RA#: _________________________
11
Rockford Fosgate
Rockford Corporation
546 South Rockford Drive
Tempe, Arizona 85281 U.S.A.
In U.S.A., (480) 967-3565
In Europe, Fax (49) 8503-934014
In Japan, Fax (81) 559-79-1265
11/01 B.M.
MAN-3776-A
Printed in U.S.A
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