RDL STCX2S Data Sheet

STICK-ON® SERIES

Model ST-CX2S
Subwoofer Filter

ANYWHERE YOU NEED...

• Active Subwoofer Equalization

• Isolated Stereo Inputs

• Adjustable Low-frequency Boost

• Very Low Noise & Distortion Filter

• STICK-ON Convenience

• RDL SupplyFlex™ Power Input

Configuration

You Need The ST-CX2S!

The ST-CX2S is a subwoofer signal equalizer in the STICK-ON series of products from Radio Design
Labs. Various mounting options permit installation right where you need it, or use it with RDL racking
accessories. The ST-CX2S offers flexibility in equalization adjustment, with the exceptional performance
RDL products are known for.

APPLICATION: The ST-CX2S features two separate isolated balanced-bridging inputs, which may each
be wired balanced or unbalanced. The output driver is 150 Ω balanced which can drive low or high
impedance balanced or unbalanced lines. The module operates at unity gain at 63 Hz (balanced input to
balanced output). A BOOST control permits adjustment of the output at 32 Hz from flat to +5.5 dB.

The ST-CX2S line-level stereo inputs are intended to bridge existing line-level feeds, and are totally
isolated from each other to produce no degradation of an existing stereo signal. A mono signal may be
connected to either one of the two inputs (and the other input remains unused). The output from the
ST-CX2S feeds the line-level input of the power amplifier being used to drive the subwoofer.

This module is the ideal companion to the RDL ST-CX2 active two-way line level crossover. The ST-CX2
modules provide line-level audio for amplified two-way systems plus a loop-through output to feed an RDL
ST-CX2S if a subwoofer is included in the system design.

The ST-CX2S features RDL’s SupplyFlex power input configuration for operation directly from ground­referenced, floating or bipolar 24 Vdc power.

Whether adding a subwoofer amplifier/speaker to an existing system, or designing an audio system with
subwoofers, the ST-CX2S is the ideal choice. Its extremely low noise and low distortion makes it suitable
for the most demanding applications. Whenever used in conjunction with other RDL RACK-UP
STICK-ON, TX™, or FLAT-PAK™ series products, the ST-CX2S can be part of the most versatile and
high performance sound systems!

RDL • 659 N. 6th St. • Prescott, AZ., USA 86301 • [phone] • FAX [phone] • www.rdlnet.com

®

,

STICK-ON® SERIES

Model ST-CX2S
Subwoofer Filter

SUBWOOFER CROSSOVER

INPUT A

ACTIVE LINE-LEVEL EQUALIZATION

GND

SIGNAL

FROM

BALANCED

LINE-LEVEL

SOURCE

Fully Clockwise

Fully
Counter­Clockwise

302010

FREQUENCY IN HERTZ

BOOST ADJUST Adjust for desired
low frequency boost. This control
is factory set to match the JBL
Model 4645 THX approved subwoofer
(THX is the registered trademark of
Lucasfilm, Ltd.). This is a 25-turn
control which sets the boost at 30 Hz.
It may be turned counterclockwise for
subwoofers not requiring this boost.

50020010050

OUTPUTINPUT B

SIGNAL

FEEDING

BALANCED

LINE-LEVEL

EQUIPMENT

+5
0

-5

-10

-15

-20

-25
DECIBELS

-30

-35

-40

-50

PWR

U

STEREO SOURCE

INPUT A

OPTIONAL JUMPER

(WHEN USING GROUND-REFERENCED POWER SUPPLY)

AUDIO

B
O
O

WIRING

S
T

25 TURN

BOOST

ADJUST

USE BOTH

INPUTS FOR

SUBWOOFER CROSSOVER

ACTIVE LINE-LEVEL EQUALIZATION

GND

OUTPUTINPUT B

24 VDC

POWER

SOURCE

Installation/Operation

EN55103-1 E1-E5; EN55103-2 E1-E4

Typical Performance reflects product at publication time
exclusive of EMC data, if any, supplied with product.
Specifications are subject to change without notice.

SUBWOOFER CROSSOVER

INPUT A

SIGNAL

FROM

UNBALANCED

LINE-LEVEL

SOURCE

ACTIVE LINE-LEVEL EQUALIZATION

GND

OUTPUTINPUT B

SIGNAL

FEEDING

UNBALANCED

LINE-LEVEL

EQUIPMENT

POWER

CROSSOVER

NE-LEVEL EQUALIZATION

GND OUTPUT

BIPOLAR SUPPLY

PWR

WIRING

B
O
O

DO NOT

S

GROUND

T

U

NEGATIVE

FOR FLOATING

OR BIPOLAR

POWER

INSTALLATION

OR

GROUND

NEGATIVE

FOR GROUND-

REFERENCED

POWER

INSTALLATION

B
O

PWR

O
S
T

U

B
O

PWR

O
S
T

U

12

OR

15

Vdc

12

OR

15

Vdc

G
N
D

TYPICAL PERFORMANCE

Input/Output Level: +4 dBu line level
Input Impedance: 50 kΩ
Input Configuration: Balanced or unbalanced, bridging
Output Impedance: 150 Ω
Output Configuration: Balanced or unbalanced line level
Output Bandwidth: 22 Hz to 80 Hz, adjustable boost

per curve
High Freq. Attenuation: Per curve, > 45 dB at 400 Hz
Gain: Unity at 63 Hz; adjustable flat to

5.5 dB at 32 Hz

Radio Design Labs Technical Support Centers

U.S.A. [phone], [phone]; Fax: [phone]

891-1147

Europe [NH Amsterdam] (++31) 20-6238 983; Fax: (++31) 20-6225-287

Headroom: 18 dB minimum at 30 Hz

(maximum boost), 22 dB typical
THD+N: < 0.05%
CMRR: > 60 dB at 60 Hz or above
Residual Noise: < 90 dB below operating level;
95 dB typical
Power Requirement: 24 to 33 Vdc @ 30 mA,
Ground-referenced or Floating
Dimensions: Height: 1.55 in. 3.94 cm
Width: 3.00 in. 7.62 cm
Depth: 0.65 in. 1.65 cm