DSM
2-CHANNEL AMPLIFIER
O W N ER' S MAN UAL
®
®
TABLE OF CONTENTS
Specifications ................................................................................... 1
Punch Accessory Pack .................................................................... 3
Introduction ...................................................................................... 4
Notes on Internal Circuitry........................................................... 4
Controls and Features...................................................................... 6
Top View of Amplifier and End Caps .......................................... 6
Front View of Power Side............................................................ 7
Side View of Input Side ............................................................... 8
Installation Considerations ............................................................... 9
Tools Needed ............................................................................ 10
Battery and Charging ..................................................................... 10
Mounting and Location................................................................... 10
Trunk Mounting ......................................................................... 10
Passenger Compartment Mounting .......................................... 11
Wiring the Punch............................................................................ 11
Power ........................................................................................ 11
Ground ...................................................................................... 11
Remote Turn-on ........................................................................ 11
Input .......................................................................................... 12
Speakers ................................................................................... 12
Mono Configuration ................................................................... 12
Passive Crossover Impedance ................................................. 13
Table of Component Values........................................................... 15
Wiring Diagrams............................................................................. 16
Troubleshooting ............................................................................. 19
Dynamic Power Measurements ..................................................... 24
Warranty Information...................................................................... 27
L'Installation / Câblage ................................................................... 28
Installation / Verkabeluug............................................................... 30
La Instalacíon / Cableado .............................................................. 32
Installazione / Elettriche ................................................................. 34
1
2
PUNCH ACCESSORY PACK
12' (365.76cm)
Blue Remote
Turn-on Wire
17'
(518.16cm)
Red Power
Wire
1.5' (45.72cm) Black
Grounding Wire
Power Ring
Terminals
Remote Turn-on Wire
Connector Plug
Hex Head and
Mounting Screws
Power Fuse Holder
Power Fuse Holder
with fuse for Punch 200
with Fuse for Punch
40, 60, and 100
Punch
Owner's
Manual
Punch
Verification
Certificate
3
INTRODUCTION
This manual provides information on the features, instal-
lation, and operation of the Punch 2-channel Amplifiers.
We suggest you save this manual for future reference.
WestronglyrecommendyouhaveyourAuthorizedRock-
ford Fosgate Dealer and Service Center install the new
Punch amplifier. If you do choose to install the amplifier
yourself, please be sure to read the entire manual before
beginning.
Notes on
Internal
Circuitry
The Rockford Punch 40DSM, 60DSM, 100DSM and
200DSM automotive stereo power amplifiers provide
state-of-the-art sound in cars, vans, boats, or wherever a
high current 12 volt power source is available.
“Discrete Surface Mount” (DSM) technology is utilized in
the crafting of all our Punch amplifiers. This process
provides greater ruggedness and consistency of both
components and layout. Already used heavily in aero-
space, industrial and automotive applications, this tech-
nology is also highly advantageous in the hostile automo-
tive environment.
The Punch adjustable input circuits are designed to
match almost any music source. The amplifiers will drive
most normal speaker types.
Internal circuitry in the Punch amplifier prevents damage
due to speaker terminal shorts. The Punch incorporates
internal battery line filtering and extensive noise preven-
tion circuitry.
The Punch Equalization circuit is best utilized and de-
signed to compensate for the acoustic inadequacies of
the automotive environment. This patented circuitry will
correct for the poor bass response and natural high
frequency roll-off inherent in the world of automotive
stereo. Theresultisfull-rangesoundwithouttheunpleas-
ant changes in the mid-range sound produced by most
tone control and equalizer circuits.
4
High powered audio amplifiers must always address the
problem of power device reliability. In particular, load fault
conditions can easily destroy an amplifier that is not
carefully designed. Rockford Fosgate has answered this
problem with the development of Real Time Power Pro-
tection (RTPP).
The RTPP circuits protect the Punch amplifiers by multi-
plying output device voltage and current values to obtain
approximate instantaneous device power. This instanta-
neous power calculation is then processed through a time
constant closely modeling the device heating time. If the
resulting modeled junction temperature exceeds a set
threshold, gate drive to the output devices is limited.
To get a better understanding of the Punch let’s take a
closer look.
5
CONTROLS AND FEATURES
Thissectiondescribesthevariouscontrolsandfeaturesof
the Punch amplifiers.
Top View of Amplifier and End Caps
Punch
Housing
The cast aluminum heatsink of the Punch is designed for
high performance cooling. The raised design of the hous-
ing allows cables and wires to run underneath the unit.
This provides for greater wiring flexibility and protects the
cables from damage caused by excessive heat and bend-
ing.
End Caps
Interchangeable end caps conceal the wiring and input
cables, giving the amplifier a clean, "stealth" look. Also
incorporated, is a holding dimple built into the end cap.
Thissmallfeatureenablesthecaptobeheldinplacewhile
being mounted.
The end caps are secured to the housing with flush
mounting, captive screws.
Mounting
Screws
Four (4) custom, round, hex screws included in the acces-
sorypackholdtheunitinplace. Thesescrewsarecovered
when the end caps are installed.
6
Front View of Power Side
REM
LED
B+/GND
Connector
Indicator
Connector
The Punch is turned on by connecting the blue remote
turn-on wire to the source unit’s “Accessory” or “Auto
Antenna” lead,eitherofwhichwillgoto+12voltswhenthe
source unit is turned on.
REM
Connector
The LED illuminates red when the unit is turned on.
LED Power
Indicator
These connectors are used to supply power and ground
to the amplifier and accept 12 AWG - 8 AWG wires.*
B+/GND
Power
Connector
*Rockford Fosgate's Perfect Interface line of accessories in-
cludes high quality power and speaker wire, gold plated RCA
interconnecting cable and other products to complete your
installation. Ask your Authorized Rockford Fosgate Dealer
about Perfect Interface.
7
Front View of Input/Output Terminals
Treble
Adjust
Bass
Adjust
Left Input
Gain Control
Right Input
Gain Control
Left Speaker
Output
RCA Input
Connectors
Right Speaker
Output
Speaker
Output
Terminals
These gold plated terminal blocks connect the Right and
Left channel outputs to the speakers and accept wire
sizes from 8 gauge through 18 gauge. Gold plated con-
nectors are immune to corrosion that can cause signal
deterioration.
Treble /
Bass
These controls adjust the amount of treble and bass
response desired. To increase the amount of response,
turn the dials clockwise; to decrease, turn the dials coun-
terclockwise.
Input
These controls are factory preset to 500 millivolts to
matchmostheadunitsandarevariablefrom250millivolts
to one volt. (More than likely they will not need
adjusting.)
Gain
Controls
If just a little volume from the source unit drives the
amplifier into distortion, reduce the input gain controls so
that the distortion doesn’t start until the source volume is
at about 3/4 of its rotation.
Input
The amplifier’s signal input, female, RCA jacks should be
Connectors connected to the source unit’s signal outputs with high-
quality RCA cables. The connectors have been plated in
gold to eliminate the possibility of corrosion that can
cause signal deterioration.
8
INSTALLATION CONSIDERATIONS
This section focuses on some of the vehicle consider-
ations for installing your new Punch amplifier. Checking
your battery and current sound system, as well as pre-
planning your system layout and best wiring routes will
save installation time. When deciding how to lay out your
new system, be sure that each component will be easily
accessible for making adjustments.
Before beginning any installation, be sure to follow these
simple rules:
1. Carefully read and understand the instructions before
attempting to install the amplifier.
2. For easier assembly, we suggest you run all wires
prior to mounting your amplifier in place.
3. Use only quality connectors for making connections.
See your Authorized Rockford Fosgate Dealer for
Perfect Interface wire enhancements.
4. 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.
5. For safety, disconnect the battery ground cable prior
to connection of the amplifier.
6. Neverrunwiresunderneaththevehicle. Thecleanest,
safest wiring connections are made by running the
wire under the carpet or behind the side panels.
Never leave wires exposed.
7. Avoidrunningwiresoverorthroughsharpedges. Use
grommets to protect wires routed through holes in
metal.
8. ALWAYS protect the battery and electrical system
from shorts with proper fusing. A fuse holder and fuse
must be installed within 18” (45.72cm) of the battery
terminal to safeguard from possible damage or injury.
9. When grounding scrape paint off metal to ensure a
good, clean ground connection. Grounding connec-
tions should be as short as possible and always be
9
connected to metal that is welded to the main body,
or chassis, of the vehicle.
The following is a list of tools you will need for installing
the Punch amplifier:
Tools
Needed
Allen Wrenches (7/64" & 3/32")
Wire Strippers
Battery Post Wrench
Electric Hand Drill with assorted bits
Voltmeter
Wire Crimpers (i.e., Perfect Interface RT-KT1)
BATTERY AND CHARGING
Punch amplifiers will naturally put an extra load on your
battery and charging system. We recommend you check
your alternator capacity to insure ample charging capa-
bility to handle the additional load of your new Punch
equipment. Stock electrical systems in good condition
should typically handle the extra load of any individual
Punch unit without problems, although battery and alter-
nator life may be slightly reduced. If problems arise, we
suggest you use a heavy duty battery and a high output
alternator.
MOUNTING AND LOCATION
The mounting location and position of the Punch will
have a great effect on its ability to dissipate the heat
generatedinnormaloperation. ThePunchhasa heatsink
designed for heat dissipation and internal shutoff cir-
cuitry to avoid overheating, so it is reasonably tolerant of
mounting variations. However, care should be taken to
ensure adequate ventilation.
Thetemperatureinsideatrunkcanreachashighas175°
F (80° C) during the summer months. Since the thermal
shutoff point for the Punch is 195° F (90° C), it is easy to
see that the amp must be mounted for maximum cooling
capability. Mounting the amplifier on the floor of the trunk
prevents sufficient convectional air flow cooling. Mount-
ing the unit vertically on a surface with the fin grooves
running up and down usually results in the best cooling.
Trunk
Mounting
10
Passenger Undertheseatorfloormountingwillworkaslongasthere
Compart-
ment
is a minimum of 1” (2.5cm) of air gap above the amplifer's
heatsink.
Mounting
Vertical mounting is still the best, and under dash mount-
ing is satisfactory as well.
WIRING THE PUNCH
Caution! Be sure to avoid running the power wires
near the input cabling antenna, power leads, sensi-
tive equipment or harnesses. The power wires carry
substantial currents and can induce noise.
The following instructions explain how to prepare the
wires for connecting the fuses and connectors. We
suggestyouperformtheseprocedurespriortowiringand
mounting your new Punch amplifier.
Preparing
Wires and
Fuses
Wiring the Fuse Holder
1. Cut approximately 18" (45.72cm) off the red power
wire. Strip one end of the short piece of wire back 1”
(2.54cm) as shown in the following diagram:
1.00"
(2.54cm)
2. Double back the piece of bared wire 1/2" (1.27cm) as
shown below.
3. Insert the wire into one end of the fuse holder so that
the insulation is just inside the crimp area as shown
in the diagram. Crimp the wire in place with the
notched portion of a crimping tool.
Crimp Here
PROTECTIVE BOOT
FUSE HOLDER
11
4. Cover the crimped area with the protective boot that
is supplied with the fuse holder.
5. Repeat the above steps to connect the remainder of
the red power wire to the other side of the fuse holder
and route to the amplifier mounting location.
Wiring the Power Connectors
1. Strip back approximately 3/8" (.95cm) of wire.
3/8"
(.95cm)
2. Insert the bared wire into the connector and crimp in
place as shown in the following diagram.
Crimp Here
Wire w/insulation
Bare
Wire
Connectors
Crimp Here
Power
The gold B+ terminal must be connected directly to the
positive (+) terminal of the battery with an appropriate
size fuse. (See the Specifications Table for more infor-
mation.) This provides a power source with a low voltage
drop and low noise. Be sure to use the supplied fuse
and fuse holder within 18" (45.72cm) of the battery’s
positiveterminal.Failuretodosomaycausedamage
to the vehicle and the amplifier.
Ifthepowerwiremustbeextendedbeyond17'(518.16cm),
we recommend you use 8 gauge, or heavier, stranded
wire.
12
TheGNDterminalgroundstheamplifierandisconnected
to the chassis of the vehicle with 12 gauge, or heavier,
stranded wire. To prevent ground loops, we recommend
you refrain from extending the ground wire beyond 18"
(45.72cm) in any installation. The ends of the Power and
Ground wires that are connected to the amplifier should
be stripped back 5/8” (1.59cm).
Ground
Remote
Turn-on
The Punch amplifiers are turned on by supplying positive
(+) 12 volts to the REM terminal. Usually the terminal is
connected to the source unit’s “Accessory” or “Auto
Antenna” lead, either of which will go to +12 Volts when
the source unit is turned on.
Although the majority of high-quality automotive source
units have an Accessory or Antenna output, there are
many which require different turn-on methods. If the
source unit has no Auto Antenna lead (or if the Auto
Antenna goes down during tape operation):
a. Find the internal switched power voltage inside
the source unit and solder a lead to it. Run the
lead out through the back of the unit (being sure
to use a grommet for insulation from the case)
and connect the Punch remote turn-on wire; or:
b. Install a switch in the car with one terminal
connectedto+12voltsandtheothertothePunch
lead.
Input
The amplifier’s signal input RCA jacks should be con-
nectedtothesourceunit’ssignaloutputswithhigh-quality
braided or double-shielded interconnecting RCA cables.
Note: Be sure to route the Punch signal input cable
away from the main power wire and the car’s wiring
harnesses to avoid noise coupling.
Speakers
Punch amplifiers are rated for safe operation into loads of
2Ω or greater in stereo mode or 4Ω in bridged mono
configurations. The primary loads on any amplifier come
from directly connected speakers without using capaci-
tors. The measured resistance for each side should not
be less than 2Ω.
13
Mono
The Punch amplifiers are capable of bridged mono
Configura- configurations. This configuration enables you to:
tion
•
•
Run a single woofer in a stereo system
Run two bridged amplifiers as a high power stereo
system
•
Run one amplifier with a bridged mono woofer and
another as a high-frequency stereo amp, etc.
For more information refer to the wiring diagrams begin-
ning on page 17.
Caution! Punch amplifiers are not recommended for
impedance loads below 2Ω stereo or 4Ω bridged.
Be sure to observe proper speaker terminal polarity
throughout the system. It is critical for the Punch to
use the correct negative terminals for right and left
channels, since the RIGHT NEGATIVE (–) terminal is
the “hot” terminal for the right speaker. DO NOT
chassis ground any of the speaker leads as unstable
operation may result.
When wiring speakers to the amplifiers, we recommend
using fuses for speaker protection. (See your Authorized
Rockford Fosgate Dealer for more information.)
A passive crossover is a circuit that employs capacitors
and/or coils and is placed on speaker leads between the
amplifier and speaker to delegate frequencies in the
speaker’s optimum performance range.
Passive
Crossover
Impedance
The most commonly used filter networks are 6 dB per
octave systems. These are easy to construct and require
a minimum number of parts. A filter network can perform
one of three functions. These are highpass (capacitors),
lowpass(inductors,chokesorcoils)andbandpass(com-
bination of a capacitor and a coil).
This result, limiting the types of frequency to the speaker,
is directly dependent upon the speaker’s impedance and
component values.
14
High and low pass filter sections have a cutoff rate that
increases as the number of components in the filter
increases. This means that a complex filter with a number
of parts will stop the unwanted frequencies faster than a
simple filter. The amount of reduction is measured in dB
per octave. The most common filters used in speaker
crossovers, as stated above, are 6 dB per octave which
uses one component per filter. Placing this filter in series
with the circuit will reduce power to the speaker by 6 dB
every octave. When passive crossover components are
used in multiple speaker systems, the crossover system’s
impedance must be considered along with the speaker’s
impedance when determining amplifier loading.
For 6 dB systems (where a single filter [highpass, lowpass
or bandpass] is used in series) the net impedance of the
system will be increased and problems are unlikely. For
example, if you are using a 4Ω speaker at 100Hz with a 6
dB filter, the net impedance will be about 5.6Ω.
12 dB per octave systems (where two filters are used in a
series for each speaker) can cause trouble. A 12 dB
choke/capacitor pair forms a series-resonant circuit to
ground. This impedance at resonance is determined by
the speaker’s dynamic independence. For example: if the
speaker is open or disconnected, the crossover input
impedance can approach ZERO at resonance resulting in
A DIRECT SHORT!
Since speaker impedance varies considerably from rated
values at various frequencies, it is common to find that
“standardized” 12 dB per octave crossovers (which are
designed for pure resistor loads) have serious impedance
dips near their crossover frequencies, possibly causing
overheating.
We recommend you use caution when using 12 dB per
octave crossover systems unless they are specifically
designed to have minimal impedance variations for the
speakers in use.
15
C
L
6 dB/Octave Low Pass
6 dB/Octave High Pass
Freq.
Hertz
Speaker Impedance
2 OHMS
8 OHMS
4 OHMS
C
L
C
L
C
L
80
100
130
4.1mH
3.1mH
2.4mH
1000µF
800µF
600µF
8.2mH
6.2mH
4.7mH
500µF
400µF
300µF
16mH
12mH
10mH
250µF
200µF
150µF
200
260
400
1.6mH
1.2mH
.8mH
400µF
300µF
200µF
3.3mH
2.4mH
1.6mH
200µF
150µF
100µF
6.8mH
4.7mH
3.3mH
100µF
75µF
50µF
600
800
1000
.5mH
.41mH
.31mH
136µF
100µF
78µF
1.0mH
.82mH
.62mH
68µF
50µF
39µF
2.0mH
1.6mH
1.2mH
33µF
26µF
20µF
1200
1800
4000
.25mH
.16mH
.08mH
66µF
44µF
20µF
.51mH
.33mH
.16mH
33µF
22µF
10µF
1.0mH
.68mH
.33mH
16µF
10µF
5µF
6000
9000
12000
51µH
34µH
25µH
14µF
9.5µF
6.6µF
.10mH
68µH
51µH
6.8µF
4.7µF
3.3µF
.20mH
.15mH
100µH
3.3µF
2.2µF
1.6µF
6 dB/Octave High and Low Pass Filters
Table of Component Values
L = Low Pass (Inductor)
C = High Pass (Capacitor)
For more information, see your Authorized Rockford Fosgate Dealer.
16
SAMPLE WIRING DIAGRAMS
B + G N D
BRIDGED
WOOFERS
L
+OUT– TREBLE GAIN IN IN GAIN BASS +OUT–
R
SOURCE UNIT
–
+
+
–
8 OHM
8 OHM
17
–
–
4 OHM
+
+
+
–
TX
TX
MBX
–
–
MX
MX
+
+
B + G N D
L
+OUT– TREBLE GAIN IN IN GAIN BASS +OUT–
R
+
+
–
–
+
–
+
+
4 OHM
–
–
3-WAY SYSTEM
18
B + G N D
–
+
L
+OUT– TREBLE GAIN IN IN GAIN BASS +OUT–
R
+ Left
– Left
+ Right
– Right
–
C-400, TT-2.5
+
C-400, TT-2.5
+
+
+
5.25"
4 OHM
SP-54
SP-44
MID-BASS
–
–
Bridged
Mono
+
+
MX124
TX124
MX124
4"
4 OHM
SP-44
MIDRANGE
–
–
TX124
+
+
1" DOME
W/CROSSOVER
4 OHM
–
SPT-14RX
SPT-14RX
–
–
C-200, TT-3.5
+
C-200, TT-3.5
+
5.25"
8 OHM
MID-BASS
+
SP-58
SP-58
–
–
+
MX124
MX124
TX128
+
4"
8 OHM
–
SP-48
SP-48
MIDRANGE
–
–
4 OHM
WOOFERS
TX128
+
1" DOME
W/CROSSOVER
8 OHM
+
SPT-18RX
SPT-18RX
–
–
Left Channel
Right Channel
COMPLETE SYSTEM
19
TROUBLESHOOTING
Problem
Connecting end caps when using large gauge wire.
Solution
Cut the wire casing on the diagonal as shown in the
followingdiagram.Insertthewireintotheconnector.Twist
thewirearoundsothatthelongendoftheinsulationfaces
up. Bend the wire prior to tightening in place.
INSULATION
STRIP WIRE
>
>
<
>
5/8"
AMP
>
Note: For easier assembly, only 5/8" (1.89cm) of wire
should be bared.
20
Problem
Amplifier will not play – Remote turn-on light is off.
Solution
1. Check the DC voltage at the amplifier's B+ terminal
with a voltmeter. The voltage should measure be-
tween 11.5V - 15.5V.
If voltage is not found, check the battery, fuse, fuse
housing and wire connections. Fix, repair, or replace
accordingly.
2. Check the voltage at the amplifier's remote turn-on
lead. Thevoltageshouldmeasurebetween11V-15V.
a. If voltage is above or below the prescribed mea-
surements, have the head unit checked by an
Authorized Dealer or Service Center.
b. If the remote turn-on current draw from the head
unit is connected to multiple amps and/or electron-
ics, the current draw may be too great. Check for
proper connections. (Use a relay to suppress the
excessive current draw.)
Ifyouarestillhavingproblems,havetheamplifierchecked
out by an Authorized Rockford Fosgate Dealer.
Problem
Amplifier will not play – Remote turn-on light is on:
Solution
1. Unplug the head unit and test the amplifier with an-
other working source unit (i.e. bench-test radio,
walkman, etc.) If the amplifier plays, check the in-dash
leads for cuts, breaks and/or shorts.
2. Disconnect the existing speakers and connect a set of
test speakers to the output of the amplifier (any type of
speaker will do - i.e. simple home box type, bookshelf,
rawspeaker, etc.). Iftheampplays, checkforshortsor
blown voice coils in the vehicle's speaker system.
Ifyouarestillhavingproblems,havetheamplifierchecked
out by an Authorized Rockford Fosgate Dealer.
21
Problem
Amplifier gets too hot.
Solution
1. Be sure the amplifier is properly mounted. You should
be able to place your hand a few inches above the
amplifierhousingandfeeltheheatrisingwhentheunit
is on.
2. Be sure the amplifier is properly vented. An ideal
situation is to have the air flow through the heatsink
fins. Hot air rises, so mount the heatsink by aligning
the fins vertically. This allows the air to flow freely,
carrying away the heat. Check to see that the heatsink
fins are free of any obstruction (i.e., carpet, seats,
etc.).
3. Check to see that the impedance of the overall system
is not less than 2Ω as described on page 14. Using an
AC impedance meter (Perfect Interface IM-1), sweep
from 20 Hz - 20 kHz, and look for dips below the 2Ω
rating.
Be sure to test the bass region (20 Hz - 150 Hz) of your
system. If the amplifier is bridged to those speakers,
the load the amp sees is one-half (1/2) of the reading
on the AC impedance meter.
If the impedance level is below 2Ω, check for bad
speakers and/or crossovers, proper use of passive
crossovers, or try rewiring the entire system.
Problem
Amplifier Noise (Turn-On Pop)
Solution
1. Disconnect the RCA plugs from the amplifier and
recheck the amp by turning the unit on and off. If turn-
on pop goes away, connect a delay turn-on module
(Perfect Interface DT-1) to the amplifier. (See your
Authorized Rockford Fosgate Dealer for more infor-
mation.)
2. Disconnecttheturn-onwirefromtheheadunitanduse
a different 12 volt power source to turn on the amplifier
(i.e. battery direct). If the noise is gone, use a relay to
22
switch from the clean power source.
Problem
Engine Noise (Whine)
Solution
1. Disconnect the speakers from the amplifier. Connect a
test speaker to the amplifier output terminals. If the
noise goes away, check your speaker leads, speakers
and crossovers.
2. Use a "shorting plug" to mute the input signal at the
amplifier. If the noise goes away:
a. Bypass all of the other equipment (i.e., crossovers
andequalizers)andconnecttheheadunitdirectlyto
the amp. If the noise disappears, reconnect the
equipment, being sure to test for noise after each
install. Logic indicates that the last unit installed is
the culprit. Refer to the unit's owner's manual for
more information.
b. Connect a new RCA line from the head unit to the
amplifier.Ifthereisnonoise,replacetheRCAcable.
c. Run the RCA cable on a different route.
d. Run a new RCA line from your head unit so there is
only one grounding point. If the noise disappears,
install the radio, using only one (1) grounding point.
Isolate the radio chassis from the grounding on the
dash, and use an antenna grounding loop isolator
on the antenna.
If noise persists, see your Authorized Rockford Fosgate
Dealer.
23
DYNAMIC POWER MEASUREMENTS
About the Dynamic Power Measurements
The Audio Graph PowerCube is a test instrument used to
measure the output of an amplifier in accordance with
IHF-202 industry standards. The IHF-202 standard is a
Dynamic power measurement and was developed as a
means of measuring power in a manner that best repre-
sents the Real World operation of an amplifier. Many
manufacturers, including Rockford Fosgate, at times will
measure amplifier power into a fixed resistor (4 ohm, 2
ohm). While this method is useful in some types of
evaluation and testing, it is not representative of an
amplifier that is connected up to a speaker and playing
music.
Music
Music is dynamic; the sound waves are complex and
constantlychanging.Inordertosimulatethis,theIHF-202
standard calls for the input signal to the amplifier to be a
1kHz bursted tone. This signal is input (on) for a short
periodoftimeandthenofffora“rested” period. Thesignal
is gradually increased in level until the amplifier's output
exceeds 1% Total Harmonic Distortion (THD). At 1%
distortion becomes audible, therefore, any power pro-
duced above that level is considered not usable. Many
manufacturers represent their amplifiers' output power in
excess of 10% distortion. They use many names for this
measurement, such as Total Maximum Power or Maxi-
mum Output Power. This is not indicative of the actual
usable output power.
Listening to Loudspeakers - Not Resistors
A loudspeaker is not a resistor. A resistor's value (resis-
tance measured in ohms) is fixed. A loudspeaker's im-
pedance is dynamic. It is constantly changing in value,
dependent upon the frequency of the input signal. There-
fore, measuring power with the amplifier loaded into a 4
ohm resistor is not the same as measuring power with the
amplifier connected to a 4 ohm speaker. Most people do
not listen to music through a resistor.
Appendix A
24
A4ohmspeakermayexperienceadropinimpedance4-
6 times lower than its nominal (printed) impedance. A
speaker will also create phase shifts in the signal that is
passed through it. These phase shifts happen because
a speaker is an inductor (voice coil) and a capacitor
(compliance of the surround/spider), as well as a resistor
(voice coil wire).
To simulate a speaker the Audio Graph PowerCube
measures output power into 20 different loads. It tests at
8 ohms, 4 ohms, 2 ohms and 1 ohm. Each of these
impedances is also tested at –60°, –30°, 0°, +30° and
+60° phase angles. These different impedances and
phase angles represent the shifts in impedance and
phase that can occur in a typical loudspeaker.
Information Cubed
Thedataacquiredinthetestingprocedureisthengraphed
in the form of a 3-dimensional cube. Hence the name
PowerCube.
The Phase Angle is expressed on the horizontal axis, the
Output Voltage is presented on the vertical axis and the
Impedance is displayed on the Z axis. Output Power, in
watts, is listed on the left hand side for each impedance
at each phase angle.
Audio Graph – The PowerCube
MODEL BEING
TESTED
VOLTAGE FROM
BATTERY
x2 = STEREO
MONO = BRIDGED MONO*
MANUFACTURERS
RATED OUTPUT
Amplifier: PUNCH 200 14.4V x 2
Serial No:
Rated Power : 75W at 4 Ohms
Owner : ROCKFORD CORPORATION
8Ω –60° 84
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
*
OUTPUT VOLTAGE
AT THE RAILS
(MOSFETS)
–30° 84
0° 83
POWER
IN
50V
30V
30° 84
60° 85
WATTS
{
4Ω –60° 159
*
–30° 154
0° 153
30° 154
60° 158
10V
2Ω –60° 266
*
–30° 251
0° 245
8Ω
4Ω
30° 248
60° 261
2Ω
–60° (Cap)
0°
1Ω
1Ω –60° 378
*
{
(Ind) +60°
{
–30° 343
0° 333
PHASE ANGLES
"MOTION OF
SPEAKER"
30° 339
60° 373
*If a Bridged/Mono, test amplifier sees 1/2 impedance (2Ω test amp sees 1Ω)
25
What is an Amplifier?
An amplifier by definition is a voltage generating device,
recreatingthesignalwhichisinputtoitidenticallybutwith
increased volume. It will be connected to a reactive load
(the speaker). The impedance of this load and phase of
the signal passing through the load will vary, dependent
upon the frequency of the input signal (music).
Therefore, a perfect amplifier will be able to maintain the
same output voltage regardless of load characteristics
and will not alter the signal it is reproducing. A perfect
amplifierwhenmeasuredbytheAudioGraphPowerCube
would present data that forms a perfect cube. Unfortu-
nately, amplifiers are not perfect. The laws of physics
generally prevent it. A great amplifier is about the best
one can hope to attain.
As you can see by the PowerCube and as you will
experiencebylistening, yourPunchamplifierisaGREAT
AMPLIFIER!
26
WARRANTY INFORMATION
Rockford Fosgate warrants all electronics to the original consumer/purchaser
to be free from defects in materials or workmanship for a period of three (3)
years. We will cover parts and labor provided the product was purchased from
an Authorized Rockford Fosgate Dealer. This warranty does not apply to any
product on which the seals and/or serial number have been broken, removed,
tampered with, defaced or altered in any manner. This warranty only applies to
the original consumer/purchaser and is not transferable.
Electronics found to be defective during the warranty period will be repaired or
replacedatRockfordFosgate’sdiscretion. Repairedorreplacedelectronicswill
be covered by the balance of the original warranty period only. Rockford
Fosgate shall not be responsible for any incidental or consequential damages
resulting from a defect in electronics. Some states do not allow the exclusion
or limitation of incidental or consequential damages, so the previous limitation
may not be applicable.
The warranty does not cover any appearance item, any cost or expense related
totheremovalorreinstallationoftheproduct,anyaccessoryusedinconjunction
with the product, damage to the product resulting from alteration, accident,
misuse or abuse, or improper installation. This warranty does not apply if the
parts or labor, which would otherwise be provided without charge under this
warranty, are obtained from any other source than Rockford Fosgate or an
Authorized Rockford Fosgate Service Center.
This warranty is the only express warranty and does not create any implied
warranties. RockfordFosgatelimitsitsobligationsunderanyimpliedwarranties
under state laws to a period not to exceed the written warranty period. Some
statesdonotallowlimitationonhowlonganimpliedwarrantylasts, sotheabove
limitation may not apply. This warranty applies only to products sold in the
United States of America or its possessions. For warranty outside the U.S.A.,
please contact the nearest Authorized Rockford Fosgate Dealer. This warranty
gives the consumer specific legal rights, and the consumer may have other
rights which vary from state to state.
A defective product must be shipped prepaid to the Authorized Rockford
Fosgate Dealer from which the consumer purchased the product or to the
Rockford Fosgate factory in Tempe, Arizona in the original factory carton or
equivalent. Any shipping loss or damage will be borne by the consumer or the
consumer’s shipper. A consumer returning a product to the factory should call
(800) 669-9899 for a Return Authorization Number. All shipments shall be
clearly marked with the Return Authorization Number on the outside of the
shipping carton.
Ship to:
Rockford Corporation
Warranty Repair Department
2055 E. 5th Street
Tempe, AZ 85281 U.S.A.
Return Authorization Number:_________________
Rockford Fosgate
A Division of Rockford Corporation
546 South Rockford Drive
Tempe, Arizona 85281 U.S.A.
In U.S.A., (602) 967-3565
In Canada, call Korbon (905) 567-1929
In Europe, Fax (49) 4207-801250
REV. B 11/93
MAN-0051
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