Rockford Fosgate XOM, Symmetry XOM Owner's/operator's Manual

METRY

CROSSOVER

[XOM]

OWNER’S/OPERATOR’S

MANUAL

Dear Customer,

Congratulations! We appreciate your purchase

of the Electronic Crossover

Module for your SYMMETRY system. As you get acquainted with the
XOM, you will find that it is not only easy to use, but also offers endless

possibilities for audio enjoyment.

For maximum performance we recommend you have your new Rockford
Fosgate product installed by an Authorized SYMMETRY Dealer, as we

provide specialized training through Rockford Technical Training Insti-

tute

(RTTI).

Please read your warranty and retain your receipt and

original carton for possible

future

use.

You will see additional SYMMETRY products introduced at regular
intervals for years to come, and your Authorized SYMMETRY Dealer can

quickly install these new optional modules at your convenience.

With

proper care and installation, SYMMETRY will provide you years of

listening enjoyment.
To add the finishing touch to your new

Rockford Fosgate image, order your

Rockford accessories, which includes everything from T-shirts and jackets,

to hats and sunglasses.
To get a free brochure on Rockford Fosgate products and Rockford

accessories, please call 602-967-3565 or FAX [phone].

PRACTICE SAFE

SOUND™

CONTINUOUS EXPOSURE TO SOUND PRESSURE LEVELS OVER

1OOdB

MAY CAUSE PERMANENT HEARING LOSS. HIGH POW­ERED AUTOSOUND SYSTEMS MAY PRODUCE SOUND PRESSURE
LEVELS WELL OVER 130dB. USE COMMON SENSE AND PRACTICE
SAFE SOUND.

©Copyright 1993 Rockford Corporation

Table Of Contents

Specifications

........................................................................ Page

1

Introduction

.......................................................................... Page

3

Remote Data Access Terminal ..............................................

Page

4

The XOVER

Menu..

............................................................... Page

5

Selecting the

Crossover Frequencies ..............................

Page

5

Adjusting the

Highpass

Crossover

.................................

Page

6

Adjusting the

Lowpass

Crossover

................................... Page

8

Adjusting the Sub Mono

Lowpass .................................. Page 9

Adjusting the Center Frequency

.................................. Page

10

Terms and Abbreviations

....................................................

Page

11

Warranty

.............................................................................

Page

13

XOM Specifications

Total Number of Outputs
Output Levels

Highpass
outputs
Slope

Minimum

F3*

Maximum F3

# F3 Points
Bandpass

1
outputs
Slope (lowside)

Minimum F3 (lowside)

Maximum F3 (lowside)
# F3 points

Slope (highside)
Minimum F3 (highside)
Maximum F3 (highside)
# F3 points

Bandpass 2
outputs
Slope (lowside)
Minimum F3 (lowside)
Maximum F3 (lowside)
# F3 points

Slope (highside)
Minimum F3 (highside)
Maximum F3 (highside)
# F3 points

Lowpass
outputs
Slope
Minimum F3
Maximum F3
# F3 points

*F3

= Cut Off Frequency

16

Each output adjustable

± 12dB

4 - FL, FR, BL, BR

12 dB/Octave

Highpass

1,820 Hz
20,650 Hz
256 points per output

4 - FL, FR, BL, BR

12 dB/Octave

highpass

125 Hz

15,000 Hz

256 points per output

12 dB/Octave lowpass
640 Hz
21,250 Hz

2.56 points per output

4 - FL, FR, BL, BR

12 dB/Octave

highpass

68 Hz

1,888 Hz
256 points per output

12 dB/Octave lowpass

9.5 Hz
3,125 Hz
256 points per output

2 - L, R (constant bass)

12 dB/Octave lowpass
57 Hz
3,000 Hz
256 points per output

-l-

Sub Lowpass

outputs

Slope
Minimum F3
Maximum F3
# F3 points

Center

Bandpass

outputs
Slope (lowside)
Minimum F3 (lowside)
Maximum F3 (lowside)
#

F3 points

Slope (highpass)
Minimum F3 (highside)
Maximum F3 (highside)
# F3 points

Electrical Specifications

Signal-To-Noise Ratio

Total Harmonic Distortion

Stereo Separation

Frequency Response

1

-

constant bass summed mono
24 dB/Octave lowpass
45 Hz
2,380 Hz
256 points

1

-

front summed mono
12 dB/Octave highpass
125 Hz
15,000 Hz

256 points

12 dB/Octave lowpass

640 Hz
21,250 Hz

256 points

>

90 dBA ref 0.750 Vrms output

>

97 dBA ref 2.300 Vrms output

<

0.03

%

ref 0.250 Vrms input

<

0.05 % ref 0.500 Vrms input

<

0.08

%

ref 0.750 Vrms input

>

72

dB

20 - 20,000 Hz ± 0.1

dB

Specifications subject to change

-2-

This manual describes the procedures for adjusting the electronic
crossover frequencies.

The XOM is one of the most versatile crossovers ever created. It takes
the four (4) preamplifier outputs from the Preamplifier Module

(PAM) and divides these signals into the following 16 outputs:

Front Left and Right Highpass
Front Left and Right Bandpass 1
Front Left and Right Bandpass 2
Back Left and Right Highpass
Back Left and Right Bandpass 1

Back Left and Right Bandpass 2

Left and Right Constant Bass

Lowpass

Summed Mono Constant Bass

Lowpass

Front Center Channel Bandpass

Each of the 16 outputs can be dynamically programmed via the
Remote Data Access Terminal (RDAT) to one of 256 possible cross­over frequencies. In addition, the output levels may be varied over
a

±l2dB range.

-3-

Remote Data Access Terminal

The Remote Data Access Terminal (RDAT) is used to gain access to
all of SYMMETRY’s features. This unit consists of a Z-line by

40-

character supertwist back-lit LCD display.

Escape

Function-

Mute

-

Volume

-

Reset

Numeric

I

Zero Set

Enter

Function Keys

Volume/Muted Keys

Numeric Keys

ESC (Escape Key)

a

(ENTER Key)

Blue Arrow Keys

Zero Set Key

Blue

Arrow

Keys

Used to select various menu options avail­able in SYMMETRY. To select an item
from the menu, press the function key
that is under the desired option.

The Up arrow key increases the volume;
the Down arrow key decreases the volume.
The mute key drops the audio by 20dB.

The 12 numeric keys are used for entering
your access code and future applications.

Returns you to the previous command or
menu. May also be used to cancel a
command, when necessary.

This key is reserved for future applica­tions.

These keys are used for various functions
throughout the system.

This key is used for various functions
throughout the system.

-4-

The Xover Menu

The XOVERMenu contains the functions for adjusting the Highpass,

Bandpass 1, Bandpass 2, Lowpass, Sub Mono and Center crossover
frequency ranges.

Note: Settings can not be adjusted if the system is locked. See the

“Basic SYMMETRY Operator’s Manual” for more informa-

tion.

Newly adjusted crossover settings will remain unchanged when

SYMMETRY is turned off.

Selecting the Crossover Frequencies

The following instructions explain how to adjust a crossover setting.

1.

From the Main Menu, press the function key directly under­neath

XOVER. The first page of the CROSSOVER Menu is

displayed as follows:

HP

* CROSSOVER MENU *

>

BP1 BP2 LP SUB

To display the second page press the blue Right arrow key.
The following is displayed:

~

lENTE,

* CROSSOVER MENU *

To return to the first page press the blue Left arrow key.

2.

To return to the Main Menu from the first page press the ESC

key.

-

5-

Adjusting the Highpass Crossover

The following instructions explain how to adjust the Highpass

crossover outputs.

1.

From the first page of the XOVER Menu, select HP. The first
OUTPUT SELECTION screen is displayed. This menu en­ables you to select the speakers on the left, right, or both left
and right sides of the vehicle.

XOM/ HP

LEFT RIGHT BOTH

Notice the message in the upper left-hand corner of the

screen. This indicates that you have selected the Highpass
crossover output.

2. Press the function key underneath the desired selection.
The second OUTPUT SELECTION screen is displayed.

This menu enables you to select the speakers in the front,
back, or both front and back areas of the vehicle. Notice
how the message in the upper left-hand corner is changed
to include

L=R.

This indicates that BOTH the left and right

sides of the vehicle were chosen in the previous screen. An

“R” in this position indicates that the Right side was se-

lected; an “L,” indicates the Left side.

-6-

The “HP, BP1 and BP2 Output Selection Table” below shows
the various combinations that may be selected.

HP, BP1 and BP2 SPEAKER SELECTION TABLE

First Output

Second Output

Results

Selection Screen Selection Screen

LEFT
LEFT
LEFT
RIGHT
RIGHT
RIGHT
BOTH

BOTH
BOTH

FRONT
BACK
BOTH
FRONT
BACK
BOTH
FRONT
BACK
BOTH

Left Front
Left Back
Left Front and Back
Right Front
Right Back
Riqht Front and Back
Left and Right Front
Left and Right Back

Left, Right, Front and

Back

3.

4.

5.

6.

Press the function key underneath the desired selection.
To return to the XOVER Menu press the ESC key once.
Once the desired crossover output is selected, its corre-

sponding CROSSOVER RESPONSE screen is displayed. Be­low is an example of a HIGHPASS CROSSOVER RESPONSE
screen.

~

To increase the cutoff frequency (F3) press the

blue

Right

arrow key. To decrease, press the blue Left arrow key.
Notice how the graph changes as you adjust the cutoff

frequency, here indicating 5030 Hz.
Use the blue Up and Down arrow keys to adjust the selected

output’s level over a 112

dB

range. To return this setting to

unity gain (0.0 dB) press the blue Zero Set Key.
When finished press the ESC key twice to return to the Main

Menu.

-7-

Adjusting the

Bandpass

1 &

Bandpass

2

Crossovers

The following instructions explain how to adjust the

Bandpass

1

and

Bandpass

2 Crossover outputs.

1.

From the first page of the XOVER MENU, select either BP1
or BP2. The first OUTPUT SELECTION screen is displayed.
This menu enables you to select the speakers on the left,
right, or both left and right sides of the vehicle.

XOM/

BP1

LEFT RIGHT BOTH

Notice the message in the upper left-hand corner of the

screen. This indicates the crossover frequency you have
selected.

XOM/BPl

indicated

Bandpass

1 and

XOM/BP2

indicates

Bandpass

2.

2. Press the function key underneath the desired selection.
The second OUTPUT SELECTION screen is displayed.

XOM/ BP1/L=R

FRONT BACK BOTH

This menu enables you to select the speakers in the front,

back, or both front and back areas of the vehicle. Notice how
the message in the upper left-hand corner is changed to
include L=R. This indicates that BOTH the left and right
sides of the vehicle were chosen. An

“R”

in this position

indicates that the Right side was selected; an

“L,”

indicates

the Left side.
See the “HP, BP1 and BP2 Speaker Selection Table” for the

various combinations that may be selected.

3.

Press the function key underneath the desired selection,
To return to the XOVER Menu press the ESC key once.

-8-

4. Once the desired crossover output is selected, its corre­sponding CROSSOVER RESPONSE screen is displayed. Be­low is an example of a BANDPASS 1 CROSSOVER RESPONSE
screen.

dB = 0.0

F3 = 303

20 200 2k 20k

. . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . .i . . . . . . . . . . . . . . . . . . .

5. To adjust the high-side cutoff frequency (F3) press the
function key on the extreme

right. To adjust the low-side

cutoff frequency,press the function key on the extreme left.

6.

To increase the cutoff frequency (F3) press the blue Right
arrow key. To decrease, press the

blue Left arrow key.

Notice how the cutoff graph changes as you adjust the

cutoff frequency, here indicating the lowpass frequency
cutoff at 303 Hz.

Use the blue Up and Down arrow keys to adjust the selected

output’s level over a ±l2dB range. To return this setting to

unity gain (O.O), press the

blue Zero Set Key.

7.

When finished press the ESC key twice to return to the Main
Menu.

-9-

Adjusting the Lowpass Crossover

The following instructions explain how to adjust the

Lowpass

Crossover outputs.

1.

From the first page of the XOVER MENU, select LP. The
output SELECTION screen is displayed. This menu enables

you to select the speakers on the left, right, or both left and

right sides of the vehicle.

XOM/ LP
LEFT RIGHT BOTH

Notice the message in the upper left-hand corner of the
screen. This indicates that you have selected the Lowpass

Crossover output.

2.

Once the desired crossover output is selected, the LP CROSS­OVER RESPONSE screen is displayed.

3.

To increase the cutoff frequency (F3) range press the blue
Right arrow key. To decrease, press the blue Left arrow key.

Notice how the graph changes as you adjust the cutoff

frequency, here indicating 80 Hz.

Use the

blue Up and Down arrow keys to adjust the Lowpass

output’s level over a ±12dB range. To return this setting to

unity gain (0.0 dB) press the

blue Zero Set Key.

4.

When finished press the ESC key twice to return to the Main

Menu.

-10-

Adjusting the Sub Mono Lowpass

Crossover

The following instructions describe the procedures for adjusting the

Crossover’s Mono Lowpass output.

1.

Select SUB from the XOVER Menu. The SUB CROSSOVER’s
RESPONSE screen is displayed.

a”“““*

2.

To increase the cutoff frequency (F3) press the blue Right

arrow key. To decrease, press the blue Left arrow key.

Notice how the graph changes as you adjust the cutoff
frequency, here indicating 202 Hz.

Use the blue Up and Down arrow keys to adjust the selected
output’s level over a ±12

dB

range. To return this setting to

unity gain (0.0 dB) press the blue Zero Set Key.

3.

When finished press the ESC key twice to return to the Main
Menu.

- ll-

Adjusting the Center Crossover

This section describes the procedures for adjusting the Center
Crossover Response curve.

1.

Press the blue Right arrow key to display the second page of

the XOVER Menu.

* CROSSOVER MENU *

CENTER

lL

I

2. Select CENTER from the XOVER Menu. The CENTER

CROSSOVER’s RESPONSE screen is displayed.

dB

= 0.0

F3 = 201

20 200 2k 20k

. . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3. To adjust the high-side cutoff frequency (F3) press the

function key on the extreme right. To adjust the low-side

cutoff frequency press

the function key on the extreme left.

4.

To increase the cutoff frequency (F3) press the blue Right

arrow key. To decrease, press the

blue Left arrow key.

Notice how the graph changes as you adjust the cutoff

frequency, here indicating the lowpass cutoff frequency at
201 Hz.

Use the

blue

Up and Down arrow keys to adjust the selected

output’s level over a

±12 dB

range. To return this setting to

unity gain (0.0

dB)

press the blue Zero Set Key.

5.

When finished press the ESC key twice to return to the Main
Menu.

Note: To LOCK the Frequency Response settings from unautho-

rized individuals, see the “Basic SYMMETRY Operator’s
Manual.

”

-12-

4b

Terms and Abbreviations

BP (band-pass filter):

BP1:

BP2:

dB (decibel):

dBA:

F3 (cutoff frequency):

Hz (hertz):

LP (lowpass):

HP (highpass):

A crossover circuit that combines a

low­pass and high-pass filter to create a band
pass.

Bandpass section optimized for higher

frequencies.
Bandpass section optimized for lower

frequencies.

The unit used to measure the difference
between two levels of a sound or electri-

cal signal; a logarithmic expression of
the ratio of two such levels. An increase
of 10

dB

represents a tenfold increase in

power. Doubling power raises the
Sound-Pressure-Level (SPL) by about 3

dB.
Decibels (A-weighted).
The point when a speaker system begins

to gradually roll off.
The standard unit of frequency. Mea-

surements in Hz represent cycles per
second, or changes away from a basic
state and back again. In audio, the basic
state is defined as either ordinary air

pressure (without sound) or its electri-

cal equivalent (constant-level DC sig­nal). The higher the Hz figure, the higher

the sound’s pitch.
A circuit in a crossover network that

passes frequencies falling below a pre­determined point and attenuates those

above.

A circuit in a crossover network that
passes frequencies falling above a prede­termined point and attenuates those
below.

-

13

-

octave: An interval between two frequencies,

the higher of which is twice that of the
lower; in modern music, an octave is
eight notes of the scale.

passband:

The continuous spectrum of frequen­cies transmitted by a filter, amplifier, or

similar device.

signal-to-noise ratio:

The specification which indicates how
much audio signal there is relative to

the noise under specified conditions. It
is the ratio of total audio output level to
the noise level expressed in

dB.

slope:

The rate at which a crossover attenuates

out-of-band frequencies. Expressed in
dB

per octave, typical slopes are 6, 12,
and 18 per octave, with 12 being the
most common; the higher the number,
the faster attenuation occurs relative to

frequency.

sound pressure level

A measurement of acoustic energy

(SPL):

expressed in

dB.

total harmonic
distortion (THD):

The percentage of an audio output sig-

nal that consists of spurious harmonics,
or multiples of the fundamental fre­quencies. These harmonics are intro­duced by a power amplifier or other
component through which the signal

passes; lower figures are better.

-

14 -

Rockford

Fosgate warrants all electronics to the original consumer pur-

chaser to be free from defects in materials or workmanship for a period of

three (3) years parts and labor provided the product was purchased from an
Authorized SYMMETRY 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 replaced at Rockford Fosgate’s discretion. Repaired or replaced
electronics will 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 to the removal or reinstallation of the product, any accessory used
in conjunction with the product, or any damage to the product resulting

from alteration, accident, misuse or abuse. 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 SYMMETRY Service Center.
This warranty is the only express warranty and does not create any implied

warranties. Rockford

Fosgate limits its obligations under any implied
warranties under state laws to a period not to exceed the written warranty
period. Some states do not allow limitation on how long an implied
warranty lasts, so the above 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 SYMMETRY 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 SYMMETRY

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 [phone] 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

205.5 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., [phone] In Canada, call Korbon [phone]

In Europe, Fax [phone] In Pacific Asia, Fax [phone]

REV A. 11 /92
MAN-0031