Xantech SR21 Installation Instructions Manual

INSTALLATION INSTRUCTIONS

SR21

SPEAKER RELAY MODULE

The SR21, Fig. 1, is an IR Remote Controlled A/B Speaker Relay Module. It allows the installer and user
to switch the output of one stereo amplifier between two speaker pairs, or, to switch one speaker pair
between the outputs of two stereo amplifiers. The switching is accomplished by way of infrared commands
originating from a Xantech RC68+ (or RC68) Programmer. It can also be switched by a DC voltage applied
between the CI (control input) and GND terminals. The RC68+ commands are "taught" to learning devices
and passed to the IR IN and GND input terminals of the SR21 via Xantech IR Receivers, Keypads and
Connecting Blocks.

SR21

0

1

CODE

7

2

6

3

5

4

IR IN
CI
GND
+12VDC

IR CONFIRM

SPEAKER RELAY
MODULE

OFF = A

ON = B

A

R+ R– L– L+

L+ L– R– R+

B

R+
R–

L–
L+

Fig. 1 The SR21

SUB-

GROUP

NOTE: The SR21 can also be used as an IR router.

FEATURES AND SPECIFICATIONS

• 4-terminal IR input (IR IN = IR Signal, CI = Control Input, GND and +12VDC) for connection of Xantech
IR Receivers, Smart Pads, Connecting Blocks and other devices.

• Three 4-terminal plug-in connectors for stereo amplifier and speaker connections.

• Isolated Left and Right grounds. Allows use of bridging type power amplifiers.

• 5 Amp/30V DC relay contact rating; provides 200 watts per channel capability into 8 Ohms.

• All plug-in connectors accept wire sizes from 24 to 12 gauge.

• IR CONFIRM LED goes ON only when an RC68 IR command signal activates unit.

• LED indicates A or B switching status.

• Four RC68+ IR commands permit OFF=A, ON=B, Pair, Toggle (A or B), and Momentary operation of
the switching relay.

• IR activated ON condition (ON=B) goes OFF (Off=A) if power is interrupted.

• +3V to +30V DC 1 mA applied to CI terminal will switch unit, instead of IR, if desired.

• Factory preset Group Code number: 50.

• CODE SUB-GROUP switch allows a choice of 8 different groups of the four RC68+ (or RC68) commands
that operate the SR21. This prevents mutual interaction in common IR systems when using more than

2

one SR21. Also, internal E

PROM can be set to different code groups, allowing up to 240 different IR code

combinations if the system uses more than eight SR21's or in combination with CC12's.

• Power: +12V DC @ 50 mA. Use the 781RG Power Supply for each SR21. If IR receivers or keypads are
used on the same 12V line, use the 782-00 Power Supply.

• Flanges, plus supplied screws, permits easy mounting to flat surfaces.

• Dimensions: 5-1/4" x 2-3/8" x 1-7/8" (133mm x 60mm x 46mm)

Remote Control Switchers



1

RC68+ PROGRAMMER / REMOTE CONTROL

The RC68+ (and RC68) Programmer (available separately) contains
all the commands necessary to operate the SR21.

• You will need it to program universal learning devices such as the
Xantech URC series learning remote, the Xantech Smart Pads, the
590 Programmable Controller, the 710 Fone Link, etc., with com­mands that operate the SR21.

• NOTE: The RC68+ codes operate several other Xantech models as
well, such as the RS41AV, RP41AV, ZPR68, etc. Therefore, only

the button descriptions that apply to the operation of the SR21
(Overlay "B") are listed below. All others should be ignored..

CAUTION: While the RC68+ will operate as a separate remote

control, it is highly recommended it not be given to the final user for the
following reasons:

• Since it includes setable code groups, the user may inadvertently
alter the installer configurations.

• Also, since the user will require IR commands from other brands of
equipment to control the total system, in addition to those of the
SR21, all commands should be consolidated into one learning
device, for ease of use.

5

CODE

SUB-

GROUP

0

1
2

3

4
5
6

7

0

80 48 10 90 01

OFF ON TGL MMT

1

00 C0 50 D0 41

OFF ON TGL MMT

2

40 A0 30 B0 21

OFF ON TGL MMT

3

20 E0 70 F0 61

OFF ON TGL MMT

4

60 88 18 98 09

OFF ON TGL MMT

5

08 A8 38 B8 29

OFF ON TGL MMT

6

28 E8 78 F8 69

OFF ON TGL MMT

7

68 C8 58 D8 49

OFF ON TGL MMT

E1 89 C9 A9 E9

71 19 59 39 79

F1 99 D9 B9 F9

B

Fig. 2 The RC68 Programmer

1

2

3

4

Place the

"B" Overlay

on the RC68+

RC68+

6

APPLICABLE RC68 BUTTON DESCRIPTIONS

1. Pair OFF Command. This button activates the IR command that turns the internal relay of the SR21

to the OFF position (the A selection).

2. Pair ON Command. This button activates the IR command that turns the internal relay of the SR21

to the ON position (the B selection).

3. TGL (toggle) Command. The first press of this button turns the relay ON (the B selection) -the second

press turns it OFF (the A selection).

4. MMT (momentary) Command. Pressing this button causes the SR21 relay to go ON (the B selection)

but stays ON only as long as the button is held down. When released, the relay returns to the OFF
position (the A selection).

5. IR Emitter Lens.

CODE SUB-GROUP

The RC6+8 has 11 rows of 5 buttons each. Each row, identified by the numbers 0 through 7 (see Fig. 2),
will execute the same set of 4 commands listed above, when selected by the CODE SUB-GROUP switch
on the SR21. This is useful to prevent mutual interaction in common IR systems when using more than one
SR21, or if CC12's are used with SR21's.

To change the CODE SUB-GROUP, simply rotate the CODE SUB-GROUP switch on the SR21 to the
number that corresponds to the desired row on the RC68+. Remove and reapply power (after 20
seconds), then use the chosen row to execute the commands for that particular SR21.

NOTE: No changes are needed on the RC68+!

6. Code Group Numbers. The SR21 is also capable of being set to different basic code groups as well

as the sub-groups.

NOTE:

When shipped from the factory, the SR21 is set to code group number 50. Be sure to

set the RC68+ to the same number!

It may be necessary to change the SR21 to a different code group if it is used in a common IR bus controlled
system with many SR21's, CC12'S, etc., to avoid mutual interaction.

2



SR21

Refer to the RC68+ instruc­tions for code group set­ting procedures.

INSTALLATION

Fig. 3 is a simple installation
where the amplifier speaker
outputs of an AM/FM receiver
are switched, by IR control,
between the speakers in a
main room and those in a
remote room.

• This system allows speak­ers to play in the main room

or

the remote room, de-

pending on the IR remote

Fig. 3 Main/Remote Speaker

Switching Using an SR21

REMOTE ROOM

L

+– +–

780-80

"J" Box

IR Receiver

+12V
GND
STATUS
IR OUT

4-Conductor Inter-room
Cable (unshielded OK)

R

+–

CODE

SUB-

GROUP

IR CONFIRM

To 120 V AC
(unswitched)

(To +12V System Status
Voltage, if desired).

Left
Speaker

0

1

7

2

6

3

5

4

IR IN
CI
GND
+12VDC

782-00

Power

Supply

SR21

SPEAKER RELAY
MODULE

OFF = A

ON = B

A

B

R+ R– L– L+

L+ L– R– R+

MAIN ROOM

SR21

Speaker Relay Module

R+
R–

L–
L+

789-44

Connecting Block

PWR

CONNECTING BLOCK

+12VDC

789-44

EMITTERS

GND

STATUS

SIGNAL

®

RCVR

IR

Right

Speaker

–

+

AM/FM Receiver

283M Blink IR™

CD Changer

283M Blink IR™

Cassette DecK

283M Blink IR™

Mouse Emitter

Micro Link™
IR Receiver

(For Main

IR Control)

490-30

Room

command sent to the SR21.

They can not play simul­taneously!

• A 780-80 provides IR control from the Remote Room. It includes a STATUS LED indicator that can be
driven by a +12V System Status (ON/OFF) source, such as an adapter plugged into the Switched AC
outlet on the AM/FM receiver.

• IR control in the Main Room is provided with a 490-30 Micro Link IR Receiver as shown (other Xantech
models could also be used).

• The 781C-00 powers the IR receivers as well as the SR21 through the 789-44 Connecting Block.

• In this type of system, you would "teach" either the Pair or the Toggle commands from the RC68 into a
learning remote to operate the SR21 (along with your other system commands).

A

B

MAIN ROOM

R+ R– L– L+

L+ L– R– R+

AM/FM Receiver #1

R+
R–

L–
L+

AM/FM Receiver #2

Fig. 4 is a basic system where the speaker outputs of

two AM/FM receivers are made available, via A/B
switching, to a stereo pair of speakers in a remote
room.

• This system is a relatively
low cost means of provid­ing two different sources to

REMOTE ROOM

SR21

Speaker

Relay Module

0

1

CODE

7

2

6

SUB-

3

5

4

GROUP

IR IN
CI
GND
+12VDC

IR CONFIRM

SR21

SPEAKER RELAY
MODULE

OFF = A

ON = B

a remote room.

• IR control in each room and
power supply consider­ations are the same as de­scribed for Fig. 3.

• To simplify the illustration,
other possible system com­ponents are not shown in
Fig. 4.

L

+– +–

780-80

"J" Box

IR Receiver

+12V
GND
STATUS
IR OUT

4-Conductor Inter-room
Cable (Unshielded OK)

R

To 120 V AC
(unswitched)

(To +12V System
Status Voltage, if desired).

Fig. 4 Amplifier A/B Switching Using an SR21

782-00

Power
Supply

789-44

Connecting Block

PWR

CONNECTING BLOCK

+12VDC

789-44

EMITTERS

GND

STATUS

SIGNAL

®

RCVR

IR

To Emitters on Other
Controlled Equipment

490-30

Micro Link™
IR Receiver

(For Main

Room

IR Control)

• Again, you would "teach"
either the Pair or the Toggle
commands from the RC68+ into a learning remote to operate the SR21 (along with your other system
commands).

Remote Control Switchers

SR21



3

Additional Remote Rooms

You may add more remote rooms to the system shown in Fig. 4. Proceed as follows:

• Use one additional SR21 for each additional remote room.

• Connect the A and B terminals of each additional SR21 in parallel to the A and B terminals of the preceding
SR21 (daisy chain).

• Connect the center 4-terminal connector to the additional remote room speakers in the same manner as
shown in Fig. 4.

NOTE: Be careful not to overload the amplifiers as you add rooms. It is recommended that you use
Xantech Match Maker speaker volume controls whenever you have three or more rooms connected in
this way, to ensure correct impedance matching.

• Connect the IR IN, GNDn +12VDC terminals in parallel also and connect the IR receiver's to these same
terminals, one from each room.

• Be sure to use the higher current power supply, model 782-00 (one only).

• Finally, set the CODE SUB-GROUP (refer to page 2) on each SR21 to a different number, to avoid mutual
operation and "teach" the commands to dedicated learning remotes for each room.

NOTE: To avoid the use of dedicated remotes, you could connect each SR21 to it's own dedicated power
supply, connecting block and room IR receiver.

USING THE SR21 AS AN IR ROUTER

The SR21 can also be used as simple 2-way IR router - to switch between two satellite receivers, TV
monitors, etc. Fig. 5 is an example of how it can be used to improve the system shown in Fig. 4 so that the
IR control is automatically switched from one AM/FM receiver to the other when the speaker outputs of the
AM/FM receivers are switched.

• In this case, be sure that both SR21's are set to the same CODE SUB-GROUP! This ensures that they
switch together when the Pair or Toggle A/B commands are sent.

• Note that both operate from the same power supply.

MAIN ROOM

SR21

Speaker

Relay Module

SR21

0

1

CODE

7

2

6

SPEAKER RELAY

SUB-

3

5

4

GROUP

MODULE

A

B

EMITTERS

R+ R– L– L+

L+ L– R– R+

To Emitters

on Other

Controlled

Equipment

R+
R–

L–
L+

White Striped
Side (+)

6015900

3.5mm-to­stripped
ends cable

Second

SR21

(for IR Routing)

IR IN
CI

OFF = A

ON = B

GND
+12VDC

IR CONFIRM

REMOTE ROOM

L

+– +–

780-80

"J" Box

IR Receiver

+12V
GND
STATUS
IR OUT

4-Conductor Inter-room
Cable (Unshielded OK)

R

Fig. 5 Using a 2nd SR21

For IR Routing

4

(To +12V System
Status Voltage, if desired).

782-00

To 120 V AC
(unswitched)

Micro Link™ IR Receiver

(For Main Room IR Control)

Power Supply

PWR

+12VDC

GND
STATUS
SIGNAL

RCVR

IR

789-44

Connecting Block

490-30

CONNECTING BLOCK

789-44

®



AM/FM Receiver #1

283M

Blink IR™

Mouse Emitter

AM/FM Receiver #2

283M

Blink IR™

R+

R–

L+

L–

L+ L– R– R+

R+ R– L– L+

A

B

ON = B

OFF = A

SR21

SPEAKER RELAY

MODULE

2

3

IR INCIGND

+12VDC

1

4

0

5

7

6

SUB-

CODE

GROUP

IR CONFIRM

SR21

1-30-01

Rev.B