Rockford EPX2 Owner's Manual

™

INSTALLATION & OPERATION

MANUAL

®®

Dear Customer,
Congratulations on your purchase of America’s finest brand of car audio compo-

nents. At Rockford Fosgate we are committed to musical reproduction at its best,
and we are pleased you chose our product. Through years of engineering expertise,
hand craftsmanship 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.

To add the finishing touch to your new Rockford Fosgate image order your Rockford
accessories, which include everything from T-shirts and jackets to hats and
sunglasses.

To get a free brochure on Rockford Fosgate products and Rockford accessories,
please call 1-800-669-9899 or FAX [phone] in the U.S. For Canada, call
Korbon Trading at 905-567-1920. For international orders FAX [phone]­8132 or call 001-1-602-967-3565.

PRACTICE SAFE SOUND™

CONTINUOUS EXPOSURE TO SOUND PRESSURE LEVELS OVER
100dB MAY CAUSE PERMANENT HEARING LOSS. HIGH POW­ERED AUTO SOUND SYSTEMS MAY PRODUCE SOUND PRES­SURE LEVELS WELL OVER 130dB. USE COMMON SENSE AND
PRACTICE SAFE SOUND.

If, after reading your manual, you still have questions regarding this prod­uct, we recommend that you see your Rockford Fosgate dealer . If you need
futher assistance, you can call us direct at 1-800-795-2385. Be sure to have
your serial number, model number and date of purchase available when
you call.

The serial number can be found on the outside of the box. Please be sure
to record it in the space provided below as your permanent record. This will
serve as verification of your factory warranty and could become useful in
recovering your product if ever stolen.

Serial Number: _________________________________________
Model Number:___________________________________

TABLE OF CONTENTS

Getting Started ..................................................................................1

EPX2 Accessory Pack.........................................................................1

Introduction ......................................................................................2

EPX2 Block Diagram....................................................................2

Technical Design Features ................................................................3

Power Supply ..............................................................................3

Preamplifier.................................................................................4

Equalizer (optional) .....................................................................5

Electronic Crossover....................................................................6

Remote Data Access Terminal (RDAT) ........................................7

Communications Interface...........................................................8

Global & VDISC Features ............................................................8

EPX2 Design Features ........................................................................9

Installation Considerations ..............................................................11

Mounting Locations ........................................................................12

Wiring the System ...........................................................................12

EPX2 Basic Connections ..................................................................14

Basic Operation ..............................................................................17

Preamp Operation...........................................................................18

Equalizer Operation (optional accessory) ........................................20

Crossover Operation .......................................................................23

Global Operation............................................................................26

Lock Operation...............................................................................30

Setup Operation..............................................................................31

About Operation .............................................................................36

Rockford Fosgate Accessories..........................................................37

Installing the Optional SYM-E14 .....................................................38

Installing the Optional SYM-E28 .....................................................39

Installing the Optional FG-BLT........................................................41

System Diagrams.............................................................................42

Troubleshooting ..............................................................................47

Specifications..................................................................................50

Warranty Information......................................................................52

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 refer to the Basic Connections section of the 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.

EPX2 ACCESSORY PACK

(1) Power Connector
(1) 18' Modular Cable
(1) Velcro Fastener
(4) Mounting Screws
(1) Allen Wrench 3/32"

– 1 –

INTRODUCTION

The Symmetry EPX2 is a technological derivative of Rockford Fosgate's
Symmetry system. It offers you a product that is both rich in features
and affordable.

The EPX2 has many features including a 4-way Preamplifier, fadable
3-way Crossover, and connections for an optional 14-band or 28-

band Equalizer. To fully appreciate the benefits offered by the EPX2,
it is necessary to examine each of its key components in detail.

SYMMETRY EPX2 BLOCK DIAGRAM

OUT

EQUALIZER

(optional)

IN

CROSSOVER

PREAMP

POWER SUPPLY AND COMMUNICATIONS

RDAT

– 2 –

OUT

TECHNICAL DESIGN FEATURES

◆ Power Supply

The power supply provides the fundamental voltages required for
circuit operation. In simplest terms, a power supply converts the
standard automotive 12 volts DC into the bipolar voltages required for
audio applications.

What makes the EPX2 Power Supply unique is that it utilizes a Self­Oscillating High Voltage Switching topology. This type of design
provides a full 1,000,000 ohms of “Power Ground / Signal Ground”
isolation. Input ground isolation is the single most effective way to
prevent alternator whine from entering an autosound installation.

CONVENTIONAL SWITCHING SUPPLY

B+ IN

RAIL +
RAIL –

ISOLATED SWITCHING SUPPLY

B+ IN

In a self-oscillating power supply, power ground and
audio ground are completely isolated.

Reduced Radio Frequency Interference (RFI) radiation is another
benefit provided by self-oscillating power supplies. RFI “desensi­tizes” the tuner section of your radio resulting in poor radio reception.
Self-oscillating power supplies generate significantly less RFI than
other switching power supply designs.

In addition to performance, reliability was another objective during
the design process. The EPX2 also incorporates Electrostatic Dis­charge Protection and Reverse-Polarity Protection.

– 3 –

RAIL +
RAIL –

◆ Preamplifier

The preamplifier section is the heart of all EPX2 signal processing
activity. It provides source selection from one of two separate input
sources, volume control covering an 80dB range, independent bass
and treble controls with ±12dB of boost or cut, and balance and fade
capabilities.

The EPX2 preamplifier has “differential inputs” to help prevent noise
problems from creeping into the audio system. A circuit that incorpo­rates differential inputs will only amplify the difference between two
conductors or wires. In car audio, most components are connected
together with RCA patch cables. Under ideal circumstances, the
difference between the hot center conductor and the outer shields is
the musical signal. Cars are anything but ideal, however. Electrical
noise is generated by the alternator, fan motors, windshield wipers,
brake lights, etc. These noises can be inductively coupled into the
RCA patch cables. When this occurs, the noise spikes appear on both
the center conductor and its outer shield. Since differential input
circuitry amplifies only the difference between the two conductors,
the noise spikes are NOT amplified, and they are consequently
eliminated from the system.

RCA INPUT

CENTER
CONDUCTOR

OUTER
SHIELD

Differential inputs only amplify the difference between two conductors.
Note: the noise spikes appear on both the center conductor and the outer
shield and therefore are not amplified.

DIFFERENTIAL

OUTPUT

To further reduce the possibility of noise, each set of RCA inputs has
its own independent audio ground. This is critically important when
dealing with systems that contain multiple source units. In every
system there should be one, and only one, point where audio ground

– 4 –

and power ground are common. This point should be established by
the source unit. When multiple source units are used, each will
establish its own common ground point, with the result being the
dreaded “ground loop.” (Ground loops are the primary cause of
engine noise in a system.) By utilizing independent input grounds, the
EPX2 preamplifier avoids ground loops.

COMMON
GROUNDS

The preamp also has individual solid-state input sensitivity controls
on the input circuitry. This, in conjunction with our unique on-line
level setting procedure, allows the installer to perfectly integrate the
EPX2 with the rest of the sound system. This on-line level setting
process is an industry first. The EPX2 system actually steps the installer
through the level setting procedure via the RDAT (Remote Data
Access Terminal). This process is more than just a series of instruc­tions. The EPX2 actually adjusts itself during this maneuver to ensure
the best possible signal-to-noise ratio, while still maintaining ad­equate signal headroom. Finally, the EPX2 is capable of producing 10
Volts RMS of output signal. This results in reduced system noise (hiss)
and maximum dynamic range.

INDEPENDENT

GROUNDS

◆ Equalizer (optional)

Equalizers (EQs) are signal processors that are used to correct or
compensate for the acoustical deficiencies inherent in most auto
sound installations. EQs are also commonly used to “tailor” the
sound of a system to the listener's own personal listening preference.
The EPX2 has the ability to integrate a 14-band or 28-band equalizer
through the use of a plug-in module.

– 5 –

Equalizer operation is exceptionally user-friendly. All adjustments are

made from the multi-function RDAT in real-time. This means that the

user can actually hear changes as they are being made. Also, all

equalizer settings are displayed both graphically and numerically on

the system's large, easy to read RDAT display. This allows the user to

instantly see exactly how much boost or cut is being applied to any

particular band.

In the past, potentiometers have been used as the control elements for

equalizers. Being the electro-mechanical devices they are, it was only

a matter of time before they became dirty or just wore out. The EPX's

equalizer utilizes state-of-the-art solid state devices as the control

elements. They don't wear out, they don't get dirty, and they'll be just

as accurate tomorrow as they are today.

The optional EQ modules feature 14 or 28 bands of adjustments to

satisfy even the most discriminating of listeners. The 14-band equal-

izer module adjusts 1/2 octave centers in the region below 1kHz, and

octave centers at 1kHz and above. The 28-band equalizer module,

commonly used in competition, allows for adjustment at 1/3 octave

centers. Left and Right channels may be calibrated independently or

simultaneously. Additionally, each band may be adjusted over a

±12dB range in exact 1dB increments.

◆ Electronic Crossover

The EPX2's active electronic crossover is, arguably, the unit's most
outstanding feature. Its primary purpose is to do to sound what a prism
does to light. That is, it splits the composite musical signal into
discrete frequency “bands.” Most loudspeakers are not capable of
efficiently reproducing the entire musical spectrum. By splitting the
music into discrete bands, individual components of the musical
signal can be routed to loudspeakers that are specifically designed to
reproduce that part of the musical spectrum.

The EPX2 features a
teen discrete outputs are provided.

Front Left and Right All Pass (passes all frequencies)
Front Left and Right High-Pass (passes high frequencies)
Front Left and Right Bandpass (passes midrange frequencies)
Back Left and Right All Pass (passes all frequencies)
Back Left and Right High-Pass (passes high frequencies)
Back Left and Right Bandpass (passes midrange frequencies)
Constant Bass Left and Right Low-Pass (passes low frequencies)

fadable

, 3-way active crossover network. Four-

– 6 –

The crossover points for high-pass, bandpass, and low-pass may be
adjusted independently. (All pass outputs do not have crossover
points.) The most flexible feature is that crossover point adjustments
may be made in real time. With the EPX2, crossover points can be
dynamically adjusted while listening. In addition, the user is not
limited to the handful of crossover points offered by most crossover
manufacturers. Each filter in the EPX2 can be set to 1 of 256 possible
frequencies, for a total of 72,057,594,000,000,000 (72 quadrillion)
unique crossover combinations.

All crossover points are represented both graphically and numerically
on the LCD display of the RDAT. High-Pass, Bandpass, and Low-Pass
transfer functions are realistically simulated on a calibrated logarith­mic frequency scale. The exact crossover frequency is displayed
numerically.

The EPX2 features a
outputs. It has outputs for both the Front and Rear of the system. Front
and Rear crossover settings for these outputs can be adjusted indepen­dently. A fadable crossover allows the user to fade the system from
front to back for just the right amount of front stage / rear fill. The
constant bass low-pass outputs provide low-pass information regard­less of the position of the fader.

fadable

crossover with constant bass low-pass

◆ Remote Data Access Terminal (RDAT)

The RDAT makes the EPX2 a unique and powerful signal processor.
The RDAT is, in reality, a very powerful computer. It coordinates the
operation of the power supply, preamp, equalizer, and crossover
sections of the EPX2, so that they all work together in perfect harmony.

The RDAT also provides the all-important link with the user. To
ensure ease of operation, a menu driven software architecture was
selected for the user interface. In this type of system, options are
presented to the user on the RDAT's large 40 character by 2 line
display. To select a particular option, the user simply presses the
function key that corresponds to the desired menu selection.

The RDAT contains a 16 bit microcontroller that runs at 20mHz. It has
a program capacity of 32k bytes and an 8k byte bank of nonvolatile
storage (saves settings when disconnected from the battery). Since all
software is written in assembly language, program coding is tight and
performance is optimal.

– 7 –

◆ Communications Interface

The communications interface provides the communications link
between the RDAT and the EPX2 unit. It accomplishes this task by
using RS-232 serial interface circuitry on all lines carrying data.
Furthermore, to maintain ground isolation, all data lines are optically
isolated from the EPX2's audio circuitry.

◆ Global and VDISC Features

The first goal of Symmetry EPX2 was to offer a great equalizer,
crossover and preamplifier all contained in one unit controlled by the
RDAT. With that goal achieved, the second goal was to make the unit
software driven allowing each of those components to interact with
one another.

After achieving the second goal the Rockford Fosgate design team
gave the EPX2 Global and VDISC features. These features work
together and are very simple to operate. The global feature allows you
to save all equalizer-crossover-preamp settings to one preset. There
are four global presets. The VDISC feature, which stands for Volume
Dependent Interactive System Control, allows you to toggle between
different global presets based on the user specified volume thresh­olds.

– 8 –

EPX2 DESIGN FEATURES

Remote Data Access Terminal

PREAMP EQ GLOBAL LOCKXOVER

LCD Display:

Function Keys:

Escape Key:

ESC

➥

Enter KeyVolume Keys

Escape Key

<

<

<

<

Multipurpose

MUTE

Function KeysLCD Display

*SYMMETRY*

<

<

123
456
7890

Numeric Keys

Keys

Menu selections and other vital system information are
displayed in this area.

The function keys are used to select options displayed
on the LCD display.

The ESC key is used to cancel a function or return to the
previous menu.

Volume Keys:

Numeric Keys:

Multipurpose
Keys:

Enter Key:

These keys are used to control the system volume level
and mute.

These keys are used for entering numeric data.
These keys are used for various operations. See Basic

Operation for additional information.
This key is reserved for future applications.

- 9 -

EPX2 Input Section

POWER

Power LED:

Balanced

The LED gives a visual indication of the status of the
EPX2, lighting when the unit is turned on.

RCA Input Jacks:

The industry standard RCA jack provides an easy
connection for signal level input. They are gold-plated
to resist the signal degradation caused by corrosion.

Balanced Line

Connector:

This input will allow the optional Balanced Line Trans­mitter to be used in conjunction with the EPX2 to
provide better noise rejection. The Balanced Line
Transmitter converts standard RCA signals to balanced
line inputs.

RDAT Interface:

The RJ11 connector is used to provide an easy 1 cable
hook-up for the Remote Data Access Terminals.

EPX2 Output Section

BACK FRONT

LEFT

INPUT A INPUT B

Balanced

RDAT

GND
B+
REM

LEFT

RIGHT

BP Output:

HP Output:

AP Output:

LP Output:

RIGHT

BP HP AP LP BP HP AP

The crossover signals from these outputs are Bandpass
frequencies. The crossover frequency is adjustable
through the RDAT.

The crossover signals from these outputs are High-Pass
frequencies. The crossover frequency is adjustable
through the RDAT.

The signals from these outputs bypass the internal
crossover and are All-Pass (Full Range) frequencies.

The crossover signals from these outputs are constant
Low-Pass frequencies. The crossover frequency is ad­justable through the RDAT.

- 10 -

INSTALLATION CONSIDERATIONS

Tools Needed

The following is a list of tools you will need for installing the EPX2.
Allen wrench 3/32" (included) Voltmeter

Wire strippers Battery post wrench
Electric hand drill w/assorted bits Wire cutters
1kHz tone recorded at “all bits high” (opt.)

This section focuses on some of the vehicle considerations for
installing your new EPX2. Checking your battery and present 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. Be sure to carefully read and understand the instructions before
attempting to install the EPX2.

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 EPX2 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 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.

-11 -

MOUNTING LOCATIONS

The mounting location of your EPX2 main housing and RDAT will
have a great effect on the performance of your system. To provide
proper ventilation the EPX2 should be mounted vertically whenever
possible.

Trunk Mounting

Mounting the EPX2 main housing in the trunk is sufficient. Leave
adequate room for the connection of cables and be careful not to
mount the unit near any vehicle computers or sources of high voltage.
Mounting the RDAT in the trunk does not allow for convenient access
and is not recommended.

Passenger Compartment Mounting

Mounting the EPX2 main housing in the passenger compartment is an
adequate location. Leave sufficient room for the connection of cables
and be careful not to mount the unit near any vehicle computers or
sources of high voltage. Mount the RDAT in a location that provides
the user with easy access. Do not expose the RDAT to water, extreme
heat, or direct sunlight.

Engine Compartment Mounting

The Rockford Fosgate EPX2 main housing and RDAT 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.

WIRING THE SYSTEM

1. Connect the EPX2 power cable

The B+ lead should be connected to a source of non-switched 12
volts DC. Prepare the length of cable from the constant +12V by
stripping 3/8" of insulation from the end of the wire. Insert the
bared wire into the B+ terminal of the power connector and fasten
the screw. The total current consumption through this lead is
approximately 2 amps.

NOTE: The B+ cable MUST be fused 18" or less from the vehicle's
battery. Install a fuse holder, along with a 3 amp fuse, under the
hood and prepare the cable ends as stated above. Connections
should be water tight.

-12 -

The REM input lead should be connected to the remote turn-on
or power antenna output from the source unit. Prepare the length
of cable from the source of switched voltage by stripping 3/8" of
insulation from the end of the wire. Insert the bared wire into the
REM terminal of the power connector and fasten the screw. Total
current consumption through this lead is negligible.

The GND lead should be connected to the chassis ground of the
vehicle. Prepare a length of cable (approximately 12" long) to be
used for the ground lead by stripping 3/8" of insulation from each
end. Insert one end of bared wire into the GND terminal of the
power connector and fasten the screw. 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
screw.

After all three wires are securely fastened, insert the power
connector into the EPX2 power socket.

2. Connect the RDAT to the EPX2 with the modular cable

Important!

is a 6 conductor non-flipped cable as opposed to the 4 conductor
flipped cable used for telephone applications.

The modular cable is NOT a standard phone cable. It

Using a standard
phone cable with the EPX2 will damage the unit and void your
warranty.

3. Connect the source inputs

Connect the front RCA outputs from the source unit to the desired
source input on the EPX2. Since fade functions take place in the
EPX2, only front outputs from the source unit are required.

If using the optional Balanced Line Transmitter, remove the cover
from the main housing with the supplied Allen wrench. Locate
and configure the signal input jumpers (J1, J2, J4, J5) to accept a
balanced line input. Replace the cover on the main housing and
connect the RCAs from the source unit to the BLT input. Attach the
mini-DIN cable to the BLT and to the desired source input on the
EPX2. For more detailed instructions refer to Page 41 of this
manual.

4. Connect the outputs

Connect the appropriate outputs from the EPX2 to the appropriate
inputs on the amplifiers.

-13 -

5. Verify operation

Power the system up by turning on the source unit. After a few
seconds, the RDAT should display the Main Menu. Keep the
volume low until the correct crossover points are set.

6. Adjust EPX2 crossover settings

Adjust the EPX2 crossover points to the desired crossover frequen­cies. To access the crossover functions, select XOVER from the
Main Menu. Then select the crossover section you wish to set up.

7. Adjust system levels

Go through the EPX2 level setting procedure. Select Setup from
the Main Menu and then select Levels. Follow the instructions
given on the screen.

EPX2 BASIC CONNECTIONS

Power Connections

PREAMP EQ GLOBAL LOCKXOVER

<

MUTE

<

POWER

*SYMMETRY*

123
456
7890

INPUT A INPUT B

BALANCED

ESC

➥

<

BALANCED

BA

Connect to B+

of battery with a

3 Amp fuse.

+ –

<

<

<

Modular

RDAT

Connect to chassis
ground of vehicle.

Less than 18"

Cable

Connect to remote

turn-on lead of

source unit.

GND
B+
REM

-14 -