
LIMITED WARRANTY
This product is warranted to the original consumer purchaser to be
free from defects in materials and workmanship under normal installation, use
and service for a period of one (1) year from the date of purchase as shown on
the purchaser’s receipt.
The obligation of Rolls Corporation under this warranty shall be
limited to repair or replacement (at our option), during the warranty period of
any part which proves defective in material or workmanship under normal
installation, use and service, provided the product is returned to Rolls Corporation, TRANSPORTATION CHARGES PREPAID. Products returned to us or to
an authorized Service Center must be accompanied by a copy of the purchase
receipt. In the absence of such purchase receipt, the warranty period shall be
one (1) year from the date of manufacture.
This warranty shall be invalid if the product is damaged as a result of
defacement, misuse, abuse, neglect, accident, destruction or alteration of the
serial number, improper electrical voltages or currents, repair, alteration or
maintenance by any person or party other than our own service facility or an
authorized Service Center, or any use violative of instructions furnished by us.
This one-year warranty is in lieu of all expressed warranties, obligations or liabilities. ANY IMPLIED WARRANTIES, OBLIGATIONS, OR
LIABILITIES, INCLUDING BUT NOT LIMITED TO THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, SHALL BE LIMITED IN DURATION TO THE ONE YEAR
DURATION OF THIS WRITTEN LIMITED WARRANTY. Some states do not
allow limitations on how long an implied warranty lasts, so the above limitation may not apply to you.
IN NO EVENT SHALL WE BE LIABLE FOR ANY SPECIAL,
INCIDENTAL OR CONSEQUENTIAL DAMAGES FOR BREACH OF THIS
OR ANY OTHER WARRANTY, EXPRESSED OR IMPLIED, WHATSOEVER. Some states do not allow the exclusion or limitation of special, incidental or consequential damages so the above limitation or exclusion may not
apply to you. This warranty gives you specific legal rights, and you may also
have other rights which vary from state to state.
Stereo Electronic
Crossover
INPUT LEVEL LOW LEVEL LOW FREQ.
CLIP
-OO dB +20
INPUT LEVEL
RIGHT CHANNEL
LOW LEVEL LOW FREQ.
OO dB 0 -OO dB 0
500
200
150
MID LEVEL HIGH MID FREQ. HIGH LEVEL
100 5K
HIGH LEVEL
750
1K
2K
3K
4K
Hz
RX321
-OO dB 0
LOW LEVEL
HIGH FREQ.
500
200
150
100 5K
HIGH FREQ.
LEFT CHANNEL
500
200
150
100 5KHz
LOW FREQ.
750
1K
2K
3K
4K
Hz
HIGH LEVEL HIGH FREQ.
750
1K
2K
3K
4K
-OO dB 0
E
C
STEREO 2-WAY / MONO 3-WAY + SUB WOOFER
500
200
150
100 5K
LOW MID FREQ.
LECTRONIC
ROSSOVER
Hz
750
1K
2K
3K
4K
RX321
SUB WOOFER
IN
OUT
MONO
3 WAY
INPUT LEVEL
CLIP
-OO dB +20
OWNERS MANUAL
Rolls Corporation
Salt Lake City, UT
1/97

FRONT PANEL DESCRIPTION
NOTE: Channel One descriptions are identical to Channel Two
INPUT LEVEL: Adjust the amount of input signal to the crossover
circuits.
LOW, HIGH LEVEL: Sets the output signal level of the indicated output
jack.
LOW,HIGH FREQUENCY: Adjusts the cut-off (3 dB down) frequency for
each crossover filter.
SUBWOOFER SWITCH: Sets the frequency at which the low filters
rolloff. Out is 20Hz, in is 80 Hz.
CLIP
-OO dB 0
LOW LEVEL
LEFT CHANNEL
500
200
150
100 5KHz
LOW FREQ.
INPUT LEVEL LOW LEVEL LOW FREQ.
-OO dB +20
INPUT LEVEL
HIGH LEVEL HIGH FREQ.
750
1K
2K
3K
4K
-OO dB 0
SUB WOOFER
750
500
200
1K
2K
150
3K
4K
100 5K
Hz
LOW MID FREQ. MID LEVEL HIGH MID FREQ. HIGH LEVEL
INPUT LEVEL
IN
OUT
-OO dB +20
MONO
3 WAY
RIGHT CHANNEL
LOW LEVEL LOW FR EQ.
CLIP
-OO dB 0 -OO dB 0
200
150
500
100 5K
750
1K
2K
3K
4K
Hz
HIGH LEVEL
200
150
HIGH FREQ.
500
Hz
100 5K
HIGH FREQ.
750
1K
2K
3K
4K
REAR PANEL DESCRIPTION
INPUT: 1/4" and XLR jacks for receiving the signal to be frequency
divided.
HIGH, LOW OUTPUTS: 1/4" and XLR jacks containing the high-frequency and low-frequency material to be sent to the power amplifiers.
SUBWOOFER OUT: 1/4" unbalanced jack containing the subwoofer
frequency signal.
INVERT/NORMAL switch: Reverses the phasing of the High Frequency
output by 180 degrees.
MONO/STEREO switch: Sets the mode of operation from Stereo 2-Way
to Mono 3-Way.
WARNING:
NRTL /C
50/60 Hz 15 VA
MADE IN U.S.A.
do not expose this device to rain or moisture.
CAUTION:
shock do not remove lid. No user
serviceable parts inside. Refer servicing
to qualified service personnel.
MODEL
RX321
120 VAC
Risk of electric shock or fire,
To reduce the risk of electric
SERIAL NUMBER
321-
RISQUE DE CHOC - NE PAS ENLEVER
HIGH
HIGH OUTPUT
NORM
INVERT
HIGH OUTPUT
RIGHT CHANNEL
LOW OUTPUT
MID OUTPUT
INPUT
WOOFER
SUB
OUT
STEREO 2-WAY MODE
HIGH
NORM
STEREO
INVERT
MONO
MONO 3-WAY MODE
HIGH OUTPUT
LEFT CHANNEL
LOW OUTPUT
LOW OUTPUT
INPUT
INPUT
MONO OPERATION
HIGH OUTPUT
HIGH OUTPUT
CONNECT TO POWER AMPLIFIER DRIVING
HIGH-FREQUENCY HORNS OR SPEAKERS
RIGHT CHANNEL
LOW OUTPUT
CONNECT TO POWER AMPLIFIER
DRIVING MID-FREQUENCY SPEAKERS
STEREO 2-WAY MODE
INPUT
WOOFER
HIGH
HIGH OUTPUT
NORM
STEREO
SUB
INVERT
MONO
OUT
MONO 3-WAY MODEMID OUTPUT
LEFT CHANNEL
LOW OUTPUT
LOW OUTPUT
SIGNAL TO BE DIVIDED (CROSSED OVER)
CONNECT TO POWER AMPLIFIER
DRIVING LOW-FREQUENCY SPEAKERS
INPUT
INPUT
FROM MIXER ETC.
For mono operation, set the Stereo/Mono switch on the rear panel IN,
ST
and see that the MONO LED on the front panel is lit. Set all level controls
to 0. Only the left channel input will be functional, and the labeling at the
bottom of the front panel should be used for setup. Connections should
be made using the reversed lettering on the rear panel as shown. After
proper connections are made and power is applied to the system, adjust
the Low, Mid and High Levels as needed.
STEREO OPERATION
HIGH OUTPUT
HIGH OUTPUT
CONNECT TO POWER AMPLIFIER DRIVING
HIGH-FREQUENCY HORNS OR SPEAKERS
SIGNAL TO BE DIVIDED (CROSSED OVER)
RIGHT CHANNEL
LOW OUTPUT
CONNECT TO POWER AMPLIFIER
DRIVING LOW-FREQUENCY SPEAKERS
FROM MIXER ETC.
INPUT
STEREO 2-WAY MODE
HIGH
NORM
STEREO
SUB
WOOFER
INVERT
MONO
OUT
MONO 3-WAY MODEMID OUTPUT
CONNECT TO POWER AMPLIFIER DRIVING
HIGH-FREQUENCY HORNS OR SPEAKERS
HIGH OUTPUT
DRIVING LOW-FREQUENCY SPEAKERS
CONNECT TO POWER AMPLIFIER
LEFT CHANNEL
LOW OUTPUT
LOW OUTPUT
SIGNAL TO BE DIVIDED (CROSSED OVER)
FROM MIXER ETC.
INPUT
INPUT
For stereo operation, ensure that the Stereo/Mono switch on the rear
panel is OUT, and the MONO LED on the front panel is not lit. Set all
INSTALLATION
The RX321 will mount in a standard 19" single rack space. It requires no
special ventilation but should be properly grounded and kept dry for
safety reasons. Use good quality input and output cableing. The RX321
has plenty of level to drive most any line or power amplifier. The 1/4"
outputs may be used TRS balanced or TS unbalanced.
level controls to 0. Connect an input signal to each of the right and left
inputs from your signal source (mixer, sound system etc.) as shown
above. Set the frequency controls to the desired crossover points consult speaker manufacturer's specifications for suggested crossover
frequencies. Connect cabling to the High and Low output jacks and to
their proper amplifier. Apply power to the entire system and adjust each
channel's High and Low Levels as needed.
2 3

SPECIFICATIONS
Input Impedance: 10kΩ XLR or 1/4" bal.
Max Input Level: +27 dB bal.
Max Output Level: +27 dB bal. XLR
Output Impedance: 50Ω
Max Gain: 20 dB
Filter Slope: 24dB/Oct.
Frequency Controls: 100Hz - 5kHz
Subwoofer Xover: 80Hz
Rumble Filter: 20Hz
S/N Ratio: 106dB
THD: <.003%
IMD (SMPTE): <.003%
CMRR: 52dB
Size: 1.75" x 6" x 19"
(4.5cm x 15cm x 48.3cm)
Po wer 120VAC (230VA C) 15VA
INTRODUCTION
Thank you for your purchase of the Rolls RX321 Stereo Two-Way/Mono
Three Way Crossover. The RX321 was designed with the most demanding audio applications in mind. The separate crossover controls and 24
dB/Octave rolloff rate provide a level of performance unmatched for the
price. The subwoofer filter and CD eq put the RX321 in a class of its own.
The frequency controls are a special 9-wiper design making them more
reliable than two or three wiper potentiometer-based crossover designs.
Because the RX321 has separate Hi-Pass and Lo-Pass filter frequency
controls, the sound engineer is no longer subjected to an "ideal" crossover curve. With the RX321, the actual crossover points may be overlapped or underlapped to provide the best solution for each specific
sound system. The RX321 also has built in 18 dB subsonic filters at 20
Hz to help protect the sound system from low transients. The versatile
inputs and outputs as well as commercial grade design make in an
important problem solver wherev er an electronic crossover is needed.
FEATURES
• Separate control of Hi-pass and Low-pass filter frequencies
• Right and Left mixed subwoofer output
• Overload lights to help prevent clipping
• Stereo 2-Way or Mono 3-Way operation
• +27 dB maximum output level to drive long lines
• Phase reversal switch on Hi-pass outputs
• Built-in subsonic filter at 20Hz
• Constant Dispersion (CD) Horn equalization available.
• True 24 dB/Octave rolloff rates, not state variable filters
• Subwoofer switch to start Low-pass filters at subwoofer frequency
• XLR balanced and 1/4" unbalanced inputs and outputs
• Professionally designed circuit board and chassis for durability
• One year limited warranty
INSPECTION
1. Unpack and Inspect the RX321 package
Your RX321 was carefully packed at the factory in a protective carton.
Nonetheless, be sure to examine the unit and the carton for any signs of
damage that may have occurred during shipping. If obvious physical
damage is noticed, contact the carrier immediately to make a damage
claim. We suggest saving the shipping carton and packing materials for
safely transporting the unit in the future.
2. Please complete the Warranty Registration Card and return it to the
factory.
14

Table of Contents
Introduction 1
Features 1
Inspection 1
Front Panel Description 2
Rear Panel Description 2
Installation 2
Stereo Two-Wa y Operation 3
Mono Three-Way Operation 3
Specifications 4
Schematic 5
Warranty Back Cover
SCHEMATIC
5