Infinity Kappa 54a 4-Ch User Manual

54a 4-Ch Power Amplifier

Owner’s Manual

Installation Guide

2 – Infinity Kappa 54a Power Amplifier

The Kappa 54a is a member of Infinity’s new Kappa series
of mobile power amplifiers. Housed within the sleek,
extruded aluminum frame, you’ll find the latest advances in
circuit topology, along with user conveniences like a wide­range input sensitivity control, auxiliary outputs, and a
built-in electronic crossover. With features like these and
more, you can quickly try out a variety of system ideas, and
because the Kappa 54a belongs to a related product family,
you’re assured future expansion will look as good as it
sounds.

KAPPA 54A AMPLIFIER FEATURES...

The Kappa 54a is a 4-channel power amplifier that offers
stereo, bridged-mono, or tri-mode operation, and is rated at
50 watts (rms) per channel into a 4-ohm load. In a bridged­mono configurations, front and rear amplifiers can deliver
up to 150 watts (rms) for the same load. The 54a also
features:

• 2-ohm operation, rated at 75 watts (rms) per channel

• Bridge/stereo switches for fast system setup

• Built-in 12 dB-per-octave electronic crossovers, variable
from 32 to 320 Hz

• Individually selectable high- and low-pass filters for all
outputs (with through-pass on amplifier outputs and
front/rear sum on auxiliary outputs)

• Amplifier input sensitivity controls to match a wide
range of input signal levels from 250 mV to 9 V

• Five protection levels guard against over-voltage, under­voltage, over-power, over-temperature, and over-current
situations

• 2-color LED array indicates green when power is on and
orange when protection is activated

• Industrial-grade, gold-plated, “pre-wire and plug-in”
connectors for an easy-to-install high-quality interface

• Transparent control cover to deter tampering yet provide
a clear view of installation settings

• Built-in automotive type fuses to protect the amplifier

• Unibloc™ chassis provides improved heat-sink capacity
and exceptional RFI shielding characteristics

ABOUT THE WARRANTY...

You’ve selected a premium product that offers superior
performance and advanced materials, resulting from over
25 years of car audio design.This Infinity product is made
with our ongoing dedication to creating the best consumer
audio products possible. As a result, you can expect your
new Kappa Power Amplifier to provide you with many
years of listening enjoyment.

All Infinity Automotive Products carry a limited parts and
labor warranty (see the enclosed warranty card), so retain
the bill of sale to protect your purchase and to aid us with
any service-related questions you may have.

ABOUT THIS MANUAL...

To attain maximum amplifier performance, we encourage
you to read the remaining pages before installing and
operating your new Infinity Kappa Power Amplifier.
Especially review the Applications section (on the next
page) for ideas on designing a system. Also, save these
instructions for future reference.

IMPORTANT: Installation of automotive stereo com­ponents can require extensive experience in performing a
variety of electrical, and mechanical procedures. Although
these instructions explain how to install a Kappa Power
Amplifier in a general sense, they do not show the exact
installation methods for your particular vehicle. If you do
not have the experience, do not attempt the installation
yourself; instead ask your Authorized Infinity Car Audio
Dealer about professional installation options.

TABLE OF CONTENTS...

Applications ..................................................3

System Expansion...........................................4

Precautions And Notes .....................................5

Installation ...................................................6

Troubleshooting..............................................8

DECLARATION OF CONFORMITY

We, Infinity Systems A/S

Kongevejen 194B

DK-3460 Birkerød

DENMARK

declare in own responsibility, that the product described in this

owner’s manual is in compliance with technical standards

EN 55013/A12/8.1994 and EN 55020/12.1994.

Steen Michaelsen
Infinity Systems A/S
Birkerød. DENMARK. 3/97

KAPPA 54A POWER AMPLIFIER

Owner’s Manual/Installation Guide – 3

For your convenience, we’ve included several application
diagrams to help you plan your own system installation.
Figures 1 through 3 show how to configure the Kappa 54a
for stereo, bridged-mono, and tri-mode operation.

For system expansion ideas, see the next page.

NOTE: For simplicity, Figures 1 through 3 do not show power,
remote, and input connections.

REM R

– –

+ +

L

R

– –

+ +

L

+

-

+

-

+

-

+

-

Set Front Mode

To STEREO

(on top panel)

Set Front Filters

To FLAT & F+R (on AUX)

(on top panel)

Set Rear Mode

To STEREO

(on top panel)

Set Rear Filter

To FLAT

(on top panel)

KAPPA 54a

(rear panel)

LR Speaker

RR Speaker

RF Speaker

LF Speaker

REM R

– –

+ +

L

R

– –

+ +

L

+

-

LF
System

+

-

RF
System

-

+

Set Front Mode

To STEREO

(on top panel)

Set Front Filters

To HP & F+R (on AUX)

(on top panel)

Set Rear Mode

To BRIDGE

(on top panel)

KAPPA 54a

(rear panel)

Rear

Subwoofer

Set Rear Filter

To LP

(on top panel)

Figure 1. This wiring
diagram shows a
Kappa 54a amplifier
driving front and rear
pairs of full-range
speakers.

Figure 2. This wiring
diagram shows a
Kappa 54a amplifier
driving a front pair of
tweeter/midrange
systems and a rear pair
of full-range speakers.

Figure 3. This wiring
diagram shows a
Kappa 54a amplifier set
for tri-mode operation
to drive a front pair of
tweeter/midrange
systems and a single
rear subwoofer.

REM R

– –

+ +

L

R

– –

+ +

L

+

-

+

-

+

-

LF
System

+

-

RF
System

Set Front Mode

To STEREO

(on top panel)

Set Front Filters

To HP & F+R (on AUX)

(on top panel)

Set Rear Mode

To STEREO

(on top panel)

KAPPA 54a

(rear panel)

LR Speaker

RR Speaker

Set Rear Filter

To FLAT

(on top panel)

APPLICATIONS

4 – Infinity Kappa 54a Power Amplifier

SYSTEM EXPANSION

+

-

+

-

+

-

+

-

5 1⁄4" Speakers

(Hi-Pass, F & R)

+

-

+

-

1" Twt.

4" Mid.

Systems

Front (Hi-Pass)

5 1⁄4" Speakers

Rear (Hi-Pass)

+

-

+

-

6" Mid/Bass Speakers

-

+

12" Subwoofer

-

+

12" Subwoofer

+

-

+

-

+

-

L/R Inputs

L/R Outputs

(F+R Sum)

L/R Inputs

L/R Inputs

L/R Outputs

(Low-Pass)

L/R Outputs

(Low-Pass)

L/R Inputs

L/R Inputs

KAPPA 54a

KAPPA 54a

KAPPA 102a

KAPPA 202a

KAPPA 202a

Front

Rear

Front

Rear

Figure 4. In this
example system, a
Kappa 54a drives
front and rear pairs of
5 1⁄4" speakers. The
54a’s stereo front and
rear outputs are
summed to feed a
bridged-mono Kappa
202a that drives a
single 12" subwoofer.

Figure 5. In this
expanded system, a
Kappa 54a drives a
front pair of
component systems
and a rear pair of
5 1⁄4" speakers. The
54a’s front low-pass
outputs feed a Kappa
102a to drive a stereo
pair of 6" mid/bass
speakers. The 102a’s
low-pass outputs feed
a bridged-mono
Kappa 202a to drive a
single 12" subwoofer.

NOTE: Many different
systems are possible
using the crossover
settings on Kappa
amplifiers, including
ones with 24 dB per
octave slopes achieved
through cascaded
configurations. For
more information,
consult your Infinity
Car Audio dealer.

Owner’s Manual/Installation Guide – 5

• The Kappa 54a has five levels of circuit protection that
monitor the amplifier and will shut it down if the
electrical system voltage drops below 10 Vdc or exceeds

15.5 Vdc, temperatures are above 194° F (90° C), short
circuits occur, or current draw exceeds product
specifications. For best performance, check the intended
mounting site to make sure the operating environment
does not create conditions that will trigger circuit
protection.

• Prior to installation, turn off all audio systems and other
electrical devices. Also disconnect the (–) negative lead
from the vehicle’s battery.

• At the installation site, locate and make a note of all fuel
lines, hydraulic brake lines, and electrical wiring. Use
extreme caution when cutting or drilling in and around
these areas.

• Use the amplifier as a mounting template to mark
locations for the mounting holes.

• Check clearances on both sides of a planned mounting
surface before drilling any holes or installing any screws.
Remember that mounting screws can extend up to an
inch behind the surface.

• Always wear protective eyewear when using tools.

• The Kappa 54a uses gold-plated, industrial-grade Weco®
plug-in connectors for power and speaker wiring. Because
of precision tolerances, do not insert the connectors into
the amplifier without pre-wiring them first. Once the
wires are fastened in each shell, they provide additional
gripping area for easy connector removal.

• When routing cables, keep input signal cables away from
power cables and output speaker wires, as shown in
Figure 6 (below).

• When making connections, make sure that each
connection is clean and properly secured. Observe the
polarity markings on the rear panel. Refer to the
application drawings (Figures 1 through 3 on page 3) to
set up the amplifier for operation in stereo, bridged­mono, bi-amp, or tri-mode configurations.

• If the amplifier’ s fuse needs replacement, use only
the same rating and type as a replacement. Do not
substitute another kind.

+–

Battery

Fuses

LF

RF

LR

RR

Kappa 54a
Amplifier

POWER and

REMOTE Cables

Chassis

Ground

Chassis
Ground

Chassis

Ground

Source
Unit

Ignition

SPEAKER Cables

AUDIO Cables

Figure 6. To minimize possible noise pickup, use this suggested cable
routing scheme to plan your amplifier installation.

PRECAUTIONS AND NOTES

6 – Infinity Kappa 54a Power Amplifier

The Kappa 54a is easy to install. For optimum
performance, we recommend using high-quality, twisted­pair shielded RCA audio cables and 14-gauge or larger
speaker wire. Also, you’ll need a minimum of 12-gauge
stranded copper wire (e.g., red and black jackets) for the
power connections. Use 18-gauge (e.g., blue jacket) wire for
remote turn-on.

Depending on your total system plan, allow for adequate
time and the possibility of overnight storage of your vehicle,
since it may take more than one day to complete the
installation.

PARTS LIST...

Examine and verify that the package includes the following
items:

• (1) Kappa 54a Power Amplifier

• (1) Spare ATC fast-blow fuse (40 A)

• (1) Control cover with (2) machine screws

• (1) Weco 5-pin audio connector

• (1) Weco 2-pin power connector

• (4) #8 mounting screws

MOUNTING THE AMPLIFIER...

The Kappa 54a can be mounted in virtually any location
inside the vehicle. However, make sure to keep the
amplifier away from heater vents or ducts.

1. At the chosen site, use the amplifier as a mounting
template and mark locations of the four mounting holes.

2. Drill a small pilot hole at each marked location.

3. Mount the amplifier and securely tighten the mounting
screws.

WIRING THE AMPLIFIER...

Refer to Figure 7 (below) for details of the Kappa 54a’s front
and rear panel connections.

1. For power, remote, and speaker wires, strip 1⁄4" off one
end of each jacket to reveal bare wire for insertion into
the Weco connectors.

2. Using the Weco 2-pin power connector, connect a black
wire from the nearest bare-metal chassis component to
the (–) terminal. Then, connect a red wire from the
vehicle’s +12-volt battery terminal to the (+) terminal.

KAPPA 54a WIRING CONNECTIONS

(front panel)

KAPPA 54a WIRING CONNECTIONS

(rear panel)

Figure 7. W iring connections for the Kappa 54a amplifier.

INSTALLATION

Owner’s Manual/Installation Guide – 7

3. Make sure the wires are firmly seated in the Weco 2-pin
connector and that each screw is completely tightened.
Insert the wired connector into the POWER socket on the
amplifier . Press it in until it stops.

4. Using the Weco 5-pin connector, connect a blue wire from
the source unit’s remote connection to the REM terminal.
Depending on polarity requirements (e.g., bridged-mono
or tri-mode configurations – see Figures 1 through 3 on
page 3), connect speaker wires from the speakers to the L
and R (+ and –) terminals, as required by your system
plan.

5. Make sure the wires are firmly seated in the Weco 5-pin
connector and that each screw is completely tightened.
Insert the wired Weco 5-pin connector into the 5-pin
socket on the amplifier. Press it in until it stops.

6. Connect RCA cables from a source unit to the L and R
INPUT jacks.

SETTING THE CROSSOVER...

IMPORTANT: If you plan to use the Kappa 54a to drive
full-range speakers, set both AMP and AUX filters to FLAT
(refer to Figure 1 on page 3 and Figure 8 below) and skip
to the next section, “Setting Input Sensitivity”.

1. Set the front and rear CROSSOVER controls to the
frequency recommended by the speaker manufacturer
(refer to Figure 8). If the value is unknown, set the control
midway .

2. Depending on your system plan, set the AMP and AUX
switches to LP (low-pass), HP (high-pass), or FLAT (refer
to Figure 8).

SETTING INPUT SENSITIVITY...

Initially, turn the front and rear input sensitivity GAIN
controls to their minimum (counter-clockwise) positions
(refer to Figure 8).

1. Reconnect the (–) negative lead to your vehicle’s battery.
Apply power to the audio system and play a favorite
music track from CD or tape.

NOTE: After the source unit is on, green LEDs (on the top
panel) will illuminate, indicating the amplifier is on. If not,
check the wiring, especially the remote connection from the
source unit. Also refer to “Troubleshooting” on the next page.

2. On the source unit, increase the volume control to
maximum position. Slowly increase the Front and Rear
GAIN controls (clockwise) towards three o’ clock and, at
the same time, listen to the quality of the reproduced
sound. At some point, you’ll hear distortion on the music
peaks. Stop the adjustment and turn it back slightly.

INSTALLING THE CONTROL COVER...

After wiring and testing the Kappa 54a amplifier, install
the control cover using the enclosed machine screws to
deter tampering and help seal out dust.

NOTE: Do not over-tighten the machine screws. Doing so may
crack the cover.

INSTALLATION (continued)

Figure 8. Kappa 54a front and rear controls for crossover, input,
and output.

8 – Infinity Kappa 54a Power Amplifier

Use the following guide to identify symptoms and solve
problems. Make sure the vehicle’s electrical system is
working properly and power is reaching the Kappa 54a (i.e.,
green LEDs on the top panel are on).

SYMPTOM LIKELY CAUSE SOLUTION

No audio Low/No Remote Check connections;

Turn-On Voltage test turn-on voltage
Speakers are not Check wiring; use

connected or are VOM/DVM to
blown measure speaker

coil impedance

Distorted audio Input sensitivity See

Setting Input

is not set properly Sensitivity on

previous page

Audio lacks Speakers are wired Check polarity of
“punch” with wrong polarity connections; refer to

Applications (page 3 )

SYMPTOM LIKELY CAUSE SOLUTION

Audio cycles A protection circuit Verify the following–
off and on; is turning the electrical system is
Amber protec- amplifier off and on between

10 ~ 15.5

Vdc;
tion LEDs (on temperature is not
top panel) are on over 194°F (90°C);

no short circuits;
speaker loads are not
less than 1 ohm
(2 ohms in mono)

Audio cycles GAIN is set too high Set Input Sensitivity
off and on; correctly (see previous
Amber protection page)
LEDs (on top
panel) are on

Fuse blows Incorrect wiring or Check connections;

short circuit refer to Applications

(see page 3)

©1997, Infinity Systems, Inc., 20630 Nordhoff Street, Chatsworth, CA 9131 1, USA

VOICE [phone] • FAX [phone]

www.infinitysystems.com

Infinity constantly strives to update and improve existing products, as well as create new ones; therefore, the specifications and construction details in this and related Infinity
publications are subject to change without notice. Unibloc is a trademark of Infinity Systems, Inc.

®

P/N SH1 103 Rev. 2

KAPPA 54A...

Power Output, 4 ohms: 4 x 50 watts
Power Output, 2 ohms: 4 x 75 watts
Power Output, Bridged 4 ohms: 2 x 150 watts
Frequency Response: 20 Hz ~ 20 kHz
Input Sensitivity: 250 mV ~ 9 V
THD + Noise (4 ohms): 0.05 %
Signal-to-Noise: > 95 dB
Maximum Current Draw: 40 A
Dimensions (w x h x l): 16 x 23⁄16 x 81⁄2 in.

406.4 x 55.6 x 215.9 mm

TROUBLESHOOTING

SPECIFICATIONS