Shure Music Mixer DFR22 User Manual

DFR22  
Audio Processor  
with Feedback Reduction  
2009 Shure Incorporated  
27B8813 (Rev. 5)  
Printed in U.S.A.  
 
ENGLISH  
DESCRIPTION  
The DFR22 Audio Processor with Feedback Reduction is a 2–input, 2–output digital audio processor. It is designed to equalize sound system  
response, provide dynamics processing and alignment delay, and automatically detect and control acoustic feedback. A built-in 2 X 2 matrix  
mixer allows either or both inputs to be routed to either or both outputs, with additional controls for levels and polarity.  
The DFR22 is ideal for installed sound reinforcement applications, such as houses of worship, theaters, and meeting facilities. It is also a  
powerful setup tool in live music applications. Using the DFR22’s drag–and–drop graphical user interface, processors can be placed any-  
where in the signal path.  
DFR22 Features  
S Shure’s patented digital feedback reduction algorithm:  
S Front and back panel RS232 ports:  
Now includes stereo DFR processing capability  
3–pin Phoenix connector on back panel.  
New Auto Clear mode clears dynamic filters after a pre-  
set change or power cycle. Dynamic filters can be auto-  
matically removed after a specified number of hours.  
DB9 connector on front panel; requires only TX, RX, and  
GND to be connected.  
S Three pre–loaded presets:  
S Configurable signal path with drag and drop Windows inter-  
face. Includes graphic and parametric EQ, up to 10 seconds  
of delay, compression, limiting, gating, automatic gain control,  
ducking, and a fully configurable two–way crossover.  
Preset 1: Two mono 16 filter DFRs.  
Preset 2: A stereo 16 filter DFR.  
Preset 3: A mono 16 filter DFR on each input. Each input  
is routed to each output.  
S Phoenix and XLR connectors for each input and output  
S Compatible with USB to serial port converters.  
S Preset selector and indicator for up to 16 presets  
S Control input pins for setting up remote preset, volume, and  
mute controls  
SPAPoCwKerINCaGbleLIST  
S Five 3-Pin Block Connector Terminals (for audio input/output  
and RS–232 communication)  
S 5-pin DIN ShureLink Cable  
S One 6-pin Block Connector Terminals (for control inputs)  
S 4 Rackmount Screws with Nylon Washers  
S One DFR22 Software CD–ROM and Online User Guide  
REQUIREMENTS  
Power Requirements  
S 100–240 Vac, 50/60 Hz  
S 45 W maximum  
Computer Requirements  
S 20 MB of hard drive space  
S CD ROM drive  
NOTE: Processor speed and memory requirements vary, depend-  
ing on the version of Windows and number of background applica-  
tions you are running. Operating the DFR22 software simulta-  
S RS–232 serial port and cable, or approved USB-to-Serial port  
neously with programs such as SIA–Smaart or Gold Line TEFt  
adapter*  
requires a faster processor and more RAM. The chart below lists  
the minimum requirements for running the DFR22 software with no  
other applications––including virus protection, firewall, instant  
messaging, or email––in the background.  
S VGA monitor with 640 x 480/256 color, or higher resolution  
S Mouse or other pointing device  
Windows Version  
98, Second Edition  
NT  
Processor Speed  
Pentium 166 MHz  
RAM  
48 MB  
64MB  
Pentium 233 MHz  
Pentium 300 MHz  
Pentium 300 MHz  
ME  
64 MB  
96 MB  
128 MB  
2000 Professional  
XP Professional, Home Pentium 300 MHz  
SOFTWARE INSTALLATION  
1. Insert supplied CD into your CD-ROM drive and follow the on-  
screen instructions.  
3. Type [D:/setup}, where “D” is your CD-ROM drive letter.  
4. Click OK and follow the on-screen instructions.  
2. If installation does NOT start automatically, click on the [Start]  
button the the Windows taskbar and select [Run...] from the  
pop-up menu.  
USING THE DFR22 SOFTWARE  
Instructions for the DFR22 software are available in PDF format on  
the CD-ROM included with the system, or on the Shure web site at  
NOTE: Register this product by filling out and mailing the enclosed  
registration card, or register online at the Shure web site  
about software updates as they become available.  
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ENGLISH  
OVERVIEW  
Front Panel  
DFR22 FRONT PANEL  
Figure 1  
1. INPUT/OUTPUT Level Meters:  
5. BYPASS DFR FILTERS Button and LEDs. Press these but-  
tons to suspend feedback reducer operation and remove feed-  
back filters from the audio path. When a Bypass LED illumi-  
nates, feedback reduction is bypassed on the corresponding  
channel. Bypass does not affect other processors (such as  
equalizers, delay, limiters, etc.).  
CLIP. Illuminates at 3 dB below clipping level.  
0 VU. +4 dBu, –10 dBV; software selectable. 0 dB is equal to  
+4 dBu by default. If the input or output sensitivity is  
changed to –10 dBV using the DFR22 software, 0 dB  
equals –10 dBV.  
6. LOAD Button. Press this button to activate a selected preset.  
–20 dB. Illuminates when the signal meets or exceeds the  
indicated level.  
7. PRESET Indicator. Shows the number of the currently active  
preset. Blinks to show the number of the other presets in the  
DFR22 when pressing the SELECT buttons.  
MUTE. Illuminates when input or output is muted.  
2. DFR Filter LEDs. Illuminate when individual feedback filters  
are active. When a filter changes or is added, an LED flashes,  
then stays on.  
8. SELECT Buttons. Press to scroll through the presets stored  
in the DFR22.  
9. COMM LED. Flashes in unison with the feedback filter LEDs  
when the detector is deploying a new filter or changing an ex-  
isting one, and also blinks whenever the unit is communicating  
with a connected computer.  
3. AUTO CLEAR Buttons and LEDs. Press and release these  
buttons to configure Auto Clear mode for each channel. Press  
them again to activate Auto Clear. When an Auto Clear LED  
illuminates, Auto Clear is active on its corresponding channel.  
10. RS232 Port. Connects the DFR22 to a computer.  
4. PRESS TO LOCK / HOLD TO CLEAR Button and LEDs.  
Press this button to lock filters at their current values. Holding  
this button down will reset all feedback filters, even if they are  
locked. The LED lights to indicate that the lock is active.  
11. POWER LED. Illuminates when 100–240 VAC power is is ap-  
plied to the DFR22.  
Back Panel  
U.S. PATENT NO. 5,999,631  
OTHER PATENT PROTECTION  
APPLIED FOR  
DFR22 REAR PANEL  
Figure 2  
1. Power Connector. Connects to 100–240 VAC power.  
7. Output Connectors ( XLR). These active, cross–coupled,  
balanced outputs can be used with balanced or unbalanced in-  
puts. They can be switched between +4 dBu/–10 dBV line–lev-  
el operation using the DFR22 software. Refer to the Audio  
Connections section.  
2. Shure Link Interface. Allows linking of up to 16 Shure Link de-  
vices, which may be accessed by a computer.  
3. 3-Pin RS-232 Port. Connects the DFR22 to a computer. For  
use with DFR22 software and control systems. Refer to the  
Computer Connections section.  
8. Input Connectors (Phoenix). These active balanced inputs  
can be used with balanced or unbalanced outputs. They can-  
not be used simultaneously with an XLR connector for the  
same input. They can be switched between +4 dBu/–10 dBV  
line–level operation using the DFR22 software. Refer to the  
Audio Connections section.  
4. CONTROL IN Pins. Use control input pins for remote control  
of preset switching, muting, and gain. Refer to the Control Pin  
Connections section.  
5. DIP Switches. Use Switches 1–4 to select a Shure Link De-  
vice ID. Use Switch 5 to lock or unlock front panel controls. Re-  
fer to the Front Panel Lockout section for information on lock-  
ing front panel controls.  
9. Input Connectors ( XLR). These active balanced inputs can  
be used with balanced or unbalanced outputs. They cannot be  
used simultaneously with a Phoenix connector for the same in-  
put. They can be switched between +4 dBu/–10 dBV line–level  
operation using the DFR22 software. See Audio Connections  
section for more information.  
6. Output Connectors (Phoenix). These active, cross–  
coupled, balanced outputs can be used with balanced or un-  
balanced inputs. They can be switched between +4 dBu/–10  
dBV line–level operation, using the DFR22 software. Refer to  
the Audio Connections section.  
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ENGLISH  
DEFAULT PRESETS  
The DFR22 comes with three factory-configured presets. Although  
a computer is required to configure the DFR22’s equalizers, dy-  
namics processors, delays, and crossover, you can use the DFR22  
“out of the box” as an automatic feedback reducer, without connect-  
ing it to a computer.  
Preset 2: Provides a stereo feedback reducer. Signal going into  
each input is analyzed independently, but the feedback reducer ap-  
plies the same notch filters to each channel. As with Preset 1, Row  
A of the DFR filters and controls on the front panel is assigned to the  
feedback reducer on Input 1; row B is assigned to the feedback re-  
ducer on Input 2. Because the feedback reducers always apply the  
same filters to both channels, the DFR filter indicators and controls  
are linked.  
Preset 1: Provides two independent feedback reducers. The  
audio signal going to Input 1 is analyzed and filtered by a feedback  
reducer using up to 16 notch filters, and is then routed to Output 1.  
Input 2 is analyzed by another feedback reducer and then routed to  
Output 2. On the front panel, Row A of the DFR Filters and controls  
is assigned to the feedback reducer on Input 1; Row B is assigned  
to the feedback reducer on Input 2.  
Preset 3:Similar to Preset 1, except both inputs are routed to both  
outputs.  
FRONT PANEL CONTROL FUNCTIONS  
Auto Clear  
By default, the DFR22 saves all feedback filters during a preset  
change or power cycle. However, you can configure the device to  
automatically remove dynamic feedback filters and changes to the  
depth of fixed feedback filters, according to parameters that you  
specify.  
Each time the DFR22 detects a feedback frequency, it assigns that  
frequency to one of the filters. By default, the first eight frequencies  
are assigned to fixed filters, and the second eight are assigned to  
dynamic filters. Both types of filters can deepen if feedback reoc-  
curs at the same frequency. The frequency of a fixed filter will not  
change unless you manually clear all of the filters. However, if all  
filters are in use and an additional feedback frequency is detected,  
the DFR22 replaces the oldest existing dynamic filter with a new fil-  
ter at a new frequency.  
Press to Lock / Hold to Clear  
Pressing these buttons locks the filters at their current values. If  
Auto Clear is not engaged, holding them down for three seconds  
resets all filters. If Auto Clear is engaged, holding them down only  
resets dynamic filters. When the PRESS TO LOCK/ HOLD TO  
CLEAR LEDs are illuminated, the Lock function is engaged and no  
filters can be added or changed. Also, the Auto Clear timer is sus-  
pended.  
Bypass DFR Filters  
Pressing the DFR BYPASS button suspends the feedback reducer  
operation and bypasses existing feedback filters. It does NOT af-  
fect any other processors. When the DFR BYPASS LED illumi-  
nates, the feedback reducer is disengaged.  
Changing Presets  
Establishing the Auto Clear Function. To establish the Auto  
Clear function, proceed as follows:  
The Preset Indicator on the front panel displays the number of the  
active preset. You can scroll through all presets stored in the device  
By pressing the arrow keys on the preset selector. When you select  
a preset number, the display blinks. If you press the LOAD button  
within five seconds, the device will make the selected preset the  
new Live preset. If you do not press the LOAD button, the preset  
will not change and the display will return to the original Live preset.  
NOTE: The procedure for setting up the Auto Clear function using  
the front panel controls differs slightly from the procedure in the  
DFR22 Windows software.  
1. Ring out the sound system to set any feedback filters that you  
want to be a permanent part of the system equalization.  
The preset indicator and controls are also used for setting the num-  
ber of hours after which each dynamic filter is removed when en-  
gaging Auto Clear.  
2. Press the Auto Clear button on the DFR22 front panel. The  
Auto Clear button will blink. Auto Clear will automatically re-  
designate any engaged filters as fixed and the rest as dynam-  
ic. For example, if you have five filters set, Auto Clear will des-  
ignate those as fixed and will designate the remaining 11 filters  
as dynamic.  
Front Panel Lockout  
When this DIP switch is in the “Unlock” position, all front panel con-  
trols are enabled. When it is in the “Lock” position, all front panel  
controls are disabled. However, all front panel indicators still func-  
tion and show the state of each parameter.  
3. The preset indicator will display a flashing [–h]. If you want  
Auto Clear to work automatically after a certain number of  
hours, you must use the Preset Select buttons to set the num-  
ber of hours (1 to 99). Each filter has its own timer, starting from  
the time it is set or changed. If you leave the preset indicator  
at [–h], Auto Clear will only work on a preset change or power  
cycle.  
You can override this DIP switch using the DFR22 software and in-  
dividually enable or disable each button on the front panel of the  
DFR22. Access to the DFR22 via a computer can only be disabled  
by setting the appropriate security level through the DFR22 soft-  
ware.  
4. Press either the LOAD button or the AUTO CLEAR button  
again. The AUTO CLEAR LED will glow steadily.  
5. When a preset is changed, or if power is turned off and on, the  
DFR filters will return to the state they were in when Auto Clear  
was engaged. If a number of hours was specified, each dy-  
namic filter and change to the depth of each fixed filter will be  
removed that many hours after it is set.  
Disengaging the Auto Clear Function. To disengage the Auto  
Clear function, press the AUTO CLEAR button again. The Auto  
Clear LED will go out, and the number of fixed filters and dynamic  
filters will reset to eight of each type.  
NOTE: Holding the clear button down while Auto Clear is engaged  
will only clear the dynamic filters.  
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ENGLISH  
DFR22 Theory  
Feedback Reduction  
No sound system (microphones + mixing/signal processing + power amplifiers/loudspeakers + room acoustics) has an absolutely flat fre-  
quency response. When the level of a sound system is increased, the frequencies at which peaks occur will be the first to exceed the feed-  
back threshold. The DFR22 attenuates these frequencies, flattening the response of the sound system. The system can then operate at a  
higher overall level.  
The DFR22 includes Shure’s patented Adaptive Notch Filter algorithm that can discriminate between feedback and non–feedback sounds.  
When this algorithm detects feedback, it inserts a shallow, narrow filter into the audio path, reducing gain at the frequency that is feeding back.  
(See Figure 3.) This filter is called a notch filter, since it affects a narrow section of the audio spectrum. If the feedback does not stop, the filter  
depth is increased. By default, filters in the DFR22 are deployed as HIGH Q filters. As a High Q filter gets deeper, its Q increases up to a Q of  
101 (1/70th of an octave). Using the DFR22 software, you can also set filters to deploy as LOW Q. Low Q filters affect a slightly wider range of  
frequencies by maintaining a Q of 14.42 (1/10th of an octave) as they deepen. By default, the DFR22 can insert up to 16 notch filters per  
channel to reduce feedback.  
The DFR22’s feedback reduction algorithm can be used as a tool during system setup and for peace of mind against unexpected feedback.  
When setting up a sound system with the DFR22, you can ring out the system by slowly raising the gain while talking into the microphones  
until the first frequency begins to feed back. The DFR22 will automatically insert a notch filter to attenuate that frequency. Once the system  
stops feeding back, you can further raise the level and repeat the process for additional frequencies. Typically, you can raise the gain 3 – 9 dB  
above the level at which feedback first occurred. You should leave some filters available to catch feedback that might occur later, when the  
sound system is in use.  
Measured Frequency Response with Peak  
Measured Frequency Response with Notch Filter Added  
EFFECTS OF NOTCH FILTER ON FREQUENCY RESPONSE  
Figure 3  
DFR22 Limitations  
The DFR22 (or any other feedback reduction processor) will not let you to increase gain beyond the physical limits of the sound system. In  
most cases, the point of diminishing returns is reached once 5 to 8 notch filters have been set. This is because there are usually only a few  
dominant peaks in a system’s frequency response (Figure 4A). In most cases, you can expect a 6 to 9 dB improvement in gain-before-feed-  
back. When you are ringing out a system and notice that many frequencies feed back simultaneously, even when you increase the gain  
slowly, you have reached the point of diminishing returns. If the system still has insufficient gain before feedback at this point, other changes  
must be made to the sound system, such as changing the placement of the microphones and/or loudspeakers.  
= Feedback Threshold  
Figure 4A  
Figure 4B  
Use notch filters to lower peaks  
Lower overall system gain  
FREQUENCY RESPONSE OF AN UNEQUALIZED SOUND SYSTEM  
Figure 4  
RACK MOUNTING THE DFR22  
Mount the DFR22 in any standard 19-inch audio equipment rack,  
using the supplied screws. Refer to Figure 5.  
NOTE: Avoid mounting wireless equipment and power amplifiers  
directly above or below the DFR22. Additional rack mount supports  
may be necessary for mobile installations.  
RACK MOUNTING THE DFR22  
Figure 5  
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ENGLISH  
POWER AND INITIALIZATION  
Power Mains Connections  
Use the supplied power cable to connect the DFR22 Audio Proces-  
sor to an active 100–240 Vac power source, as shown in Figure 6.  
The Power LED on the front panel will glow green when power is  
applied.  
NOTE: The DFR22 Audio Processor is designed to operate contin-  
uously. Therefore, there is no power on/off switch.  
..  
Power LED  
DFR22 POWER CONNECTION  
Figure 6  
Initialization  
Once power is applied, the DFR22 Audio Processor takes approxi-  
mately 5 seconds to initialize. When initialization is complete, the  
Input/Output LEDs will flash, as shown in Figure 7. The DFR22 is  
ready to use once the LEDs stop flashing.  
DFR22 INITIALIZATION  
Figure 7  
AUDIO CONNECTIONS  
NOTE: Audio will pass from the inputs to the outputs, even if it has  
CAUTION: DO NOT connect equipment to both the Phoenix  
and XLR connectors of the same input or output at the same  
time. Doing so could damage the equipment.  
not yet been configured through the computer interface.  
Wiring Connectors  
DFR22 XLR CONNECTORS (OUTPUT)  
DFR22 XLR CONNECTORS (INPUT)  
2
1
3
XLR  
Male)  
RCA  
RCA  
XLR  
(Female)  
Phone Plug  
(Balanced)  
Phone Plug  
(Unbalanced)  
Phone Plug  
(Balanced)  
Phone Plug  
(Unbalanced)  
DFR22 PHOENIX CONNECTOR OUTPUTS / INPUTS  
XLR  
Female)  
XLR  
Male)  
RCA  
Phone Plug  
Phone Plug  
(Balanced) (Unbalanced)  
INPUT/OUTPUT CONNECTOR WIRING DIAGRAMS  
Figure 8  
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ENGLISH  
12 dB and 18 dB Output Pads  
Each DFR22 output has a 12 dB pad and an 18 dB pad that can be  
engaged through the software interface. Use these pads when con-  
necting the DFR22 to lower-level inputs. They cannot be used to  
prevent clipping at the output stage of the DFR22  
NOTE: The Output meters indicate the signal level present at the  
digital-to-analog converters. The 12 and 18 dB pads act upon the  
signal after the digital-to-analog converters, so the meters do not  
reflect the pads.  
COMPUTER CONNECTIONS  
RS-232 Connections  
Connect the COM port on your computer to the 9-pin RS-232 con-  
nector on the front panel of the DFR22, shown in Figure 9, using a  
male-to-female serial cable. Pin outs for a 9–pin RS–232 cable are  
shown in Figure 10 and listed in Table 1.  
NOTE: Only the TX, RX, and GND pins need to be connected in  
order to communicate with the DFR22.  
RS-232  
You can also connect a computer or control system to the 3–pin  
RS-232 Phoenix connector on the back panel of the DFR22, as  
shown in Figure 11.  
IMPORTANT: You CANNOT connect two PCs to the DFR22 at the  
same time. However, you CAN connect an AMX or Crestron sys-  
tem and a PC to the DFR22 at the same time.  
PHOENIX RS-232 SERIAL PORT CONNECTION  
Figure 11  
RS-232 SERIAL PORT CONNECTION  
Figure 9  
Table 1. RS-232 PIN OUTS  
DFR22  
––  
COMPUTER  
––  
PIN NO.  
COMPUTER 9-PIN RS-232  
MALE CONNECTOR  
9-PIN FEMALE  
TO COMPUTER  
1
2
3
4
5
6
7
8
9
TX  
RX  
RX  
––  
TX  
DTR  
GND  
DSR  
RTS  
CTS  
––  
GND  
––  
DFR22 9–PIN RS-232  
FEMALE CONNECTOR  
9-PIN MALE  
TO DFR22  
––  
––  
RS-232 CABLE PINOUTS  
Figure 10  
––  
Shure Link Network  
Up to 16 Shure Link devices, including the DFR22, DFR11EQ,  
DP11EQ, P4800, and UA888, can be linked and controlled from  
one computer. Using 5-pin DIN cables, connect the Shure Link IN  
and Shure Link OUT of each device, as shown in Figure 12.  
NOTE: The last device in the chain MUST be connected to the  
first device (the one connected directly to the computer) to  
form a loop.  
SHURELINK IN  
DEVICE ID # 0  
RS-232  
DEVICE ID # 1  
DEVICE ID # 2  
SHURELINK OUT  
SHURELINK NETWORK CONNECTIONS  
Figure 12  
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ENGLISH  
DIP Switch Settings for Networked Devices  
Assign each Shure Link device a unique Device ID Number, using  
DIP Switches 1–4, as shown in Figure 13. Refer to Table 2 for De-  
vice ID settings.  
Table 2. DEVICE ID SETTINGS  
DIP Switch  
DIP Switch  
Device  
ID  
Device  
ID  
1
2
3
4
1
2
3
4
IMPORTANT: Each Shure Link device MUST have a unique  
Device ID number.  
0
1
2
3
4
5
6
7
DN DN DN DN  
UP DN DN DN  
DN UP DN DN  
UP UP DN DN  
DN DN UP DN  
UP DN UP DN  
DN UP UP DN  
UP UP UP DN  
8
9
DN DN DN UP  
UP DN DN UP  
DN UP DN UP  
UP UP DN UP  
DN DN UP UP  
UP DN UP UP  
DN UP UP UP  
UP UP UP UP  
10  
11  
12  
13  
14  
15*  
*Default setting.  
DIP SWITCH SETTINGS FOR NETWORKED DEVICES  
Figure 13  
CONTROL PIN CONNECTIONS  
The control pins on the back of the DFR22 connect to switches, potentiometers, and controller hardware. The Control Input pins can be used  
to change presets, adjust gain, and mute channels.  
NOTE: Use the DFR22 software to configure the control pins so that they match the attached control hardware. You can also use the software  
to assign minimum and maximum gain values for each control, as well as the gain increment for up/down volume control buttons. Refer to the  
Control Pin section of the Online Help or to the Online User Guide.  
Determining Control Pin Allocations  
Table 3. BINARY CONTROL PIN ALLOCATION  
When allocating control pins, you should first determine which pins  
are to be used for preset control. Any remaining pins can then be  
used to adjust gain or to mute channels. The number of pins need-  
ed for preset control depends on the type of control hardware used,  
as well as the number of presets.  
Number of Presets  
Pin Numbers  
2
4
1
1 and 2  
8
1–3  
16  
1–4  
The following methods can be used to allocate control pins:  
S One-to-One: Use one pin for each preset, starting at Pin 1,  
and proceeding toward the right. You MUST use consecutive  
pins. Connect momentary or latching switches.  
S Shure DRS10 Switch: Use Pin 1 for up to 10 presets.  
S Custom Switch: Use Pin 1 for up to 10 presets.  
S Binary: Use the pin numbers listed in Table 3. Connect latch-  
ing switches.  
Preset Control Connections  
Various types of control hardware can be connected to the Control  
Input pins, as shown in Figure 14. When properly configured, the  
DFR22 changes to the appropriate preset in response to the  
switch. Resistor values for custom switches and the Shure DRS10  
are listed in Table 4.  
One-to-one Configuration  
(Each pin represents one preset)  
NOTE: The total resistance of the cable run, from the switch to the  
DFR22, should be less than 100 ohms. Two-conductor, unshielded  
cable, such as a Belden 8442, is recommended.  
Table 4. CUSTOM SWITCH RESISTOR VALUES  
PRESET  
RESISTOR VALUE  
1
Binary Configuration  
97 kΩ  
44–60 kΩ  
26–32 kΩ  
2
3
4
17–20 kΩ  
5
6
7
8
9
10  
11.3–13.6 kΩ  
7.8–9.3 kΩ  
5.2–6.3 kΩ  
3.3–4.1 kΩ  
1.9–2.5 kΩ  
0.63–1.1 kΩ  
Shure DRS10 or Custom Switch Configuration*  
WIRING CONTROL INPUT PINS FOR PRESET CONTROL  
Figure 14  
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ENGLISH  
Mute Control Connections  
For mute control, use either a latching switch or a momentary  
switch. The total resistance of the cable run from the switch to the  
DFR22 should be less than 100 ohms.  
Figure 15 shows an example of how to connect either a latching  
switch or a momentary switch to the Control Input pins to mute an  
input or an output.  
Ground  
Switch  
(momentary or latching)  
MUTE CONTROL PIN CONNECTIONS  
Figure 15  
Gain Control Connections  
For gain control, use either a potentiometer or two momentary  
switches (one for gain up and one for gain down). If you want to  
have multiple sets of gain controls acting on the same inputs or out-  
puts, use momentary switches connected in parallel. Figure 16  
shows a typical connection between a potentiometer and the Con-  
trol Input pins. Figure 17 shows a typical connection between two  
momentary switches and the Control Input pins.  
10kW Potentiometer  
(Audio Taper)  
GAIN CONTROL PIN CONNECTIONS USING A POTENTIOMETER  
Figure 16  
When using a potentiometer, the total resistance of the cable run  
should be less than 100 ohms.  
Switch  
(momentary)  
When using momentary switches, the total resistance of the cable  
run should be less than 100 ohms.  
NOTE: As supplied, the DFR22 control pins are configured for use  
with a 10 Kohm audio taper potentiometer. However, you can use  
the Potentiometer Calibration Wizard in the DFR22 software to  
configure the DFR22 for use with any 10 Kohm, 20 Kohm, 50  
Kohm, or 100 Kohm linear or audio taper potentiometer.  
Ground  
Switch  
(momentary)  
GAIN CONTROL PIN CONNECTIONS USING SWITCHES  
Figure 17  
AMX / Crestron Control Connections  
You can connect an AMX or Crestron controller to the back panel  
RS-232 port, using a Phoenix connector, or to the front panel  
RS-232 port, using a DB-9 connector. In either case, you only need  
to connect three wires: send, receive, and ground. See page 8 for  
the pinout of the RS-232 ports.  
To access AMX/Crestron control codes for the DFR22, visit the  
DFR22.asp.  
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ENGLISH  
SPECIFICATIONS  
Frequency Response  
Certifications  
20 Hz to 20 kHz ±1 dB  
cULus. Listed and cUL Listed to UL 6500 and CSA E60065. Au-  
thorized under Verification provision of FCC Part 15 as a Class B  
Digital Device.  
Dynamic Range  
110 dB minimum, A-weighted, 20 Hz to 20 kHz  
Sampling Rate  
This Class B digital apparatus complies with Canadian ICES–003.  
48 kHz  
Conforms to European Union Directives, eligible to bear CE  
marking. Meets European Union Low Voltage Requirements:  
Certified to EN 60065. Meets applicable tests and per-  
formance criteria in European Standard EN55103 (1996) parts 1  
and 2, for residential (E1) and commercial and light industrial  
(E2) environments.  
Digital-to-Analog, Analog-to-Digital Conversion  
24 bit  
Impedance  
Input: 10 kΩ  
Output: 120 Ω  
Input Clipping Level  
+24 dBu minimum  
NOTE: EMC conformance testing is based on the use of sup-  
plied and recommended cable types. The use of other cable  
types may degrade EMC performance.  
Output Clipping Level  
+24 dBu  
+12 dBu (with 12 dB pad)  
+6 dBu (with 18 dB pad)  
EMC conformance testing is based on the fact that the computer  
is used for setup purposes only and disconnected during EMC  
testing.  
Total Harmonic Distortion  
< 0.05%, +4 dBu, 20 Hz to 20 kHz  
Propagation Delay from Input to Output  
<1.5 ms  
Polarity  
Input to output: non-inverting (inverting optional)  
Operating Voltage  
100–240 Vac, 50/60 Hz (auto-switching), 1 A, maximum  
Maximum Power Drain  
45W  
Temperature Range  
Operating: –7_ to 49_ C (19_ to 120_ F)  
Storage: –29_ to 74_ C (–20_ to 165_ F)  
Dimensions  
482.6 mm x 247.7 mm x 44.4 mm (19 in. x 9.75 in. x 1.75 in.)  
(See Figure 18)  
Weight  
2.83 kg (6.25 lbs)  
Furnished Accessories  
Power Cable (DFR22) . . . . . . . . . . . . . . . . . . . . . . . . 95B8389  
Power Cable (DFR22E) . . . . . . . . . . . . . . . . . . . . . . . 95C8247  
5-pin DIN Shure Link Cable . . . . . . . . . . . . . . . . . . . . 95B8676  
Hardware Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90AY8100  
12 Block Connector Terminals, 3-pin  
(for audio inputs and outputs)  
2 Block Connector Terminals, 10-pin  
(for control inputs and outputs)  
4 Rackmount Screws and Washers  
Optional Accessories  
DRS10 Wallplate unit with 10-position rotary switch for preset  
control  
DFR22 DIMENSIONS  
Figure 18  
9
 
ENGLISH  
Information to User  
Changes or modifications not expressly approved by Shure Incorporated could void your authority to operate this equipment.  
This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful  
interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference  
to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can  
be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:  
S Reorient or relocate the receiving antenna.  
S Increase the separation between the equipment and receiver.  
S Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.  
S Consult the dealer or an experienced radio/TV technician for help.  
LIMITED TWO YEAR WARRANTY  
Shure Incorporated (“Shure”) hereby warrants that this product will be free from defects in materials and workmanship for a period of two years  
from the date of purchase. At its option Shure will repair or replace the defective product and promptly return it to you, or refund the purchase price.  
You should retain proof of purchase to validate the purchase date and return it with any warranty claim.  
If you believe this product is defective within the warranty period, carefully repack the unit, insure it, and return it postage prepaid to:  
Shure Incorporated  
Attention: Service Department  
5800 W. Touhy Avenue  
Niles, IL 60714-4608 U.S.A.  
Outside the United States, return the product to your dealer or Authorized Service Center.  
This warranty does not apply in cases of abuse or misuse of the product, use contrary to Shure’s instruction, or unauthorized repair. All implied  
WARRANTIES OF MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE are hereby disclaimed and Shure hereby disclaims liabil-  
ity for incidental, special, or consequential damages resulting from the use or unavailability of this product.  
Some states do not allow limitations on how long an implied warranty lasts, or the exclusion or limitation of incidental or consequential damages,  
so the above limitation may not apply to you. This warranty gives you specific legal rights, and you may have other rights which vary from state  
to state.  
10  
 
SHURE Incorporated http://www.shure.com  
United States, Canada, Latin America, Caribbean:  
5800 W. Touhy Avenue, Niles, IL 60714-4608, U.S.A.  
Phone: 847-600-2000 U.S. Fax: 847-600-1212 Intl Fax: 847-600-6446  
Europe, Middle East, Africa:  
Shure Europe GmbH, Phone: 49-7131-72140 Fax: 49-7131-721414  
Asia, Pacific:  
Shure Asia Limited, Phone: 852-2893-4290 Fax: 852-2893-4055  
 

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