Crest Audio X-RACK XRM User manual

owner’s manual
X-Rack rack mount mixers
XRM - 12 Output Monitor Mixer

1Save the carton and packing materials!
Should you ever need to ship the unit,
use only the original factory packing.
For replacement packaging, call Crest Audio’s
Customer Service Department directly.
2Read all documentation before
operating your equipment. Retain all
documentation for future reference.
3Follow all instructions printed on
unit chassis for proper operation.
4Do not use the unit if the electrical
power cord is frayed or broken.
The power supply cord should be rout-
ed so that it is not likely to be walked on
or pinched by items placed upon or
against it.
5Always operate the unit with the
AC ground wire connected to the
electrical system ground. Precautions
should be taken so that the means of
grounding of a piece of equipment is not
defeated.
6Damage caused by connection to
improperAC voltage is not covered
by any warranty.
7Do not spill water or other liquids
into or on the unit, or operate the
unit while standing in liquid.
8The power cord of equipment
should be unplugged from the out-
let when left unused for a long peri-
od of time.
Service Information
Do not open unit!
Opening the unit will expose you to
potentially dangerous voltages.There are
no user serviceable parts inside.
Equipment should be serviced by
qualified service personnel when:
A. The equipment has been exposed to rain.
B. The equipment does not appear to oper-
ate normally, or exhibits a marked change in
performance.
C. The equipment has been dropped, or the
enclosure damaged.
To obtain service:
contact your nearest Crest Audio
Service Center, Distributor, Dealer,
or Crest Audio at 201.475.4600 USA
or visit www.crestaudio.com for addi-
tional information.
email [e-mail]
This symbol is used to alert
the operator to follow important
procedures and precautions
detailed in documentation.
This symbol is used to warn opera-
tors that uninsulated “dangerous
voltages” are present within the
equipment enclosure that may
pose a risk of electrical shock.
XRM owner’s manual
Important precautions

4
1
2
3
Master section P .29
Solo and Monitoring System, Output Masters.
Front panel controls and rear panel connectors.
Stereo Input channels p.19
Front panel controls and rear panel connections
Mono Input channels p. 7
Front panel controls and rear panel connections
table of contents
Introduction
Thank you and congratulations on your purchase of your new
Crest Audio X-Rack mixer.We’re confident that you will enjoy
many years of trouble-free service from it.You will quickly find
that it fits into a wide variety of mixing applications with ease.
Due to well thought out sets of features, coupled with intelli-
gent circuit design and the highest standards in construction &
workmanship, all Crest Audio console products excel above and
beyond the competitor’s products, in every area.
This owner’s manual covers the XRM X-Rack mixer.The XRM
has 12 Mono inputs and 4 Stereo inputs, adding up to a total of
20 microphone inputs. Each input can feed any of 12 outputs.
Please read this manual thoroughly and keep it handy for future
reference. If you have any operating concerns that are not cov-
ered in this manual, or have application questions of any type,
don’t hesitate to contact Crest Audio directly either by phone,
fax, or email. Here is our technical support contact information:
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Specifications P. 4 1

XRM owner’s manual
p.4
XRM block diagram
BAL XLR
IN
BAL LINE IN
INPUT
PREAMP
GAIN
10 - 70 dB
FOUR BAND EQ
LEVEL
LF LOW MID HI MID HF
HPF
LINE
(MIC PAD)
26dB
PA D
PRE-SOURCE
SELECT
PRE
SOURCE
MUTE ?
SOLO DC
+10
MUTE
INSERT
SEND / RTN
+48V ON
EQ ON
FADER AMP
PRE-SOURCE
BUFFER
NO
YES
SOLO LEFT MAIN
RIBBON
CABLE
-
40 WAY
XRM MONO INPUT MODULE
12 MONO INPUTS AVAILABLE
HPF
70Hz
-18dB/Oct
FREQ
INPUT
SIGNAL
LED
PRE
FADER
POST
FADER
LEVEL LEVELFREQ LEVEL
SOLO RIGHT
12 KHZ400 - 8 KHZ80 - 2 KHZ80 HZ
XRM BLK DIA-REV1.0 - 5/20/02
PFL
SOLO
TRIGGER
CHAN
FADER
MIX 1-4
PRE
PRE
FADER
PRE
EQ
PRE
INSERT
REAR PANEL
GAIN
15 - 60 dB
FOUR BAND EQ - LEFT
LEVEL
LF LOW MID HI MID HF
LINE
(MIC PAD)
PRE
SOURCE
MUTE ?
+10
MUTE
+48V ON
EQ ON FADER
AMPS
PRE-SOURCE
BUFFERS
NO
YES
SOLO LEFT
XRM STEREO INPUT MODULE
4 STEREO INPUTS AVAILABLE
SUM
MONO FREQ
POST
FADER
L & R
LEVEL LEVELFREQ LEVEL
SOLO RIGHT
12 KHZ400 - 8 KHZ80 - 2 KHZ80 HZ
PFL
SOLO
TRIGGER
CHAN
LEVEL
PRE
FADER
PRE
EQ
REAR PANEL
BAL LINE IN
INPUT
PREAMP
26dB
PA D
LF LOW MID HI MID HF
12 KHZ400 - 8 KHZ80 - 2 KHZ80 HZ
FOUR BAND EQ - RIGHT
+10
PRE-SOURCE
SELECT
PRE
FADER
PRE
EQ
LEFT
RIGHT
LEFT
RIGHT
LEFT
RIGHT
LEFT
RIGHT
PRE
FADER
L & R
PRE-AMP
OUT
L & R
PRE
FADER
POST
FADER
PRE
EQ
ODD MIX
BAL OUT
MIX INSERT
SEND / RTN
XRM MIX PAIR
1 OF 6 PAIRS SHOWN
ODD
MIX AMP
+10
PEAK
(AFL)
SIG
SIG/PK
LED
POST
FADER
ODD
FADER
60MM
PRE
FADER
ODD MIX
BUS IN
SOLO DC
SOLO LEFT
SOLO RIGHT
AFL-ODD
PEAK
(PFL)
SIG
TO
PEAK
CIRCUIT
R
G
INPUT
SIGNAL
LED
PEAK
(PFL)
SIG
R
G
SOLO DC
TO
PEAK CIRCUIT
G
R
M1 M2
MONITOR
OUT - L
MONITOR / HP
LEVEL
L
R
HEADPHONE
AMP
SOLO LEFT
SOLO
MIX AMPS
SOLO DC
SOLO
FEED
L - R
SOLO CONTROL LOGIC
+9
6 3 0
-3
6 9
12 15 18 21 24
SOLO
ON
PWR
ON
LED
METERS
FOLLOW SOLO
ON
POWER
AC IN
100-240V
50 / 60 Hz
80W
X-RACK REAR PANEL:
AC INLET & SWITCH
UNIVERSAL INPUT-VOLTAGE
SWITCHING POWER SUPPLY
+17V
-17V
+12V
+48V
INTERNALLY FUSED AND
SHORT-CIRCUIT PROTECTED
TO POWER
DISTRIBUTION
RIBBONS
ANALOG
GROUND
AUX DC
GROUND
SAFETY
GROUND
TO CHASSIS CHASSIS
GROUND
BNC CONNECTOR
FOR 12VOLT LAMP
( ON FRONT PANEL )
SHORT-CIRCUIT
PROTECTION
POLY
FUSES
XRM BLOCK DIAGRAM
GC
PGAIN
ROTARY
POT PAD LED
AMP PANEL
SWITCH
FADER
FET
SWITCH
BALANCED
DRIVER
ALL SWITCHES SHOWN IN THE UP (DESELECTED) POSITION AMP(LIFIER) GAIN SHOWN IN DB WHEN NEEDED WHEN SHOWN: 1/4” TRS SWITCHING JACKS HAVE NORMALLY CLOSED CONTACTS USER OPTIONS IMPLEMENTED WITH REMOVABLE LINKS AND SOLDER BLOBS DEFAULT OPTION POSITION SHOWN UNDERLINED
GROUND COMP
DRIVER
BICOLOR
LED
1/4” TRS
JACK
XLR
JACK
OBE
FRANK
ELECT
SWITCH
STANDARD OUTPUT LEVEL IS +4 dBu AT 0 VU PIN 2 HOT ON ALL BALANCED INPUTS AND OUTPUTS (XLR JACKS) FOR UNBALANCED OPERATION: TIE PIN 3 TO PIN 1, USE PIN 2 FOR OUTPUT, PIN 1 FOR GND “Ø” SYMBOL INDICATES POLARITY REVERSE LEGENDS
USER OPTIONS
SOLDER
BLOB
FITTED
LINK RCA
JACK
SOLO
LINK
IN OUT
Use 5-Pin DIN cable to
interconnect two Consoles
SOLO-LINK CONNECTORS.
USE 5-PIN DIN CABLE FROM
SLAVE CONSOLE OUT
TO MASTER CONSOLE IN
SOLO-LINK:
TIES SOLO AUDIO AND
CONTROL BETWEEN
CONSOLES. SLAVE SOLOS
SHOW UP ON MASTER
CONSOLE.
DC OUTPUT
PIN 1 LIFT
MIX SENDS 1 & 2
LEV / LEV
__
LEV / PAN
SWITCHING
M3 M4
MIX SENDS 3 & 4
LEV / LEV
__
LEV / PAN
SWITCHING
M5 M6
MIX SENDS 5 & 6
LEV / LEV
__
LEV / PAN
SWITCHING
M7 M8
MIX SENDS 7 & 8
LEV / LEV
__
LEV / PAN
SWITCHING
M9
M10
MIX SENDS 9 & 10
LEV / LEV
__
LEV / PAN
SWITCHING
M11 M12
MIX SENDS 11 & 12
LEV / LEV
__
LEV / PAN
SWITCHING
26dB
PA D
PIN 1 LIFT
SPLIT
OUT
BAL XLR
IN
SPLIT
OUT
BAL XLR
IN
SPLIT
OUT
MIX 1-4
PRE
M1 M2
MIX SENDS 1 & 2
LEV / LEV
__
LEV / PAN
SWITCHING
PRE
FADER
M3
M4
MIX SENDS 3 & 4
LEV / LEV
__
LEV / PAN
SWITCHING
M5 M6
MIX SENDS 5 & 6
LEV / LEV
__
LEV / PAN
SWITCHING
M7
M8
MIX SENDS 7 & 8
LEV / LEV
__
LEV / PAN
SWITCHING
M9
M10
MIX SENDS 9 & 10
LEV / LEV
__
LEV / PAN
SWITCHING
M11
M12
MIX SENDS 11 & 12
LEV / LEV
__
LEV / PAN
SWITCHING
SUM
HPF
HPF
40Hz
-18dB/Oct
EVEN MIX
BAL OUT
MIX INSERT
SEND / RTN
EVEN
MIX AMP
+10
PEAK
(AFL)
SIG
SIG/PK
LED
POST
FADER
EVEN
FADER
60MM
PRE
FADER
EVEN MIX
BUS IN
G
R
HPF
HPF
40Hz
-18dB/Oct
STEREO PAIR
STEREO
PA I R
LO-CUT
ON
AFL-EVEN
CTRL TO
INPUT SENDS
SOLO
LOGIC
&
SWITCH
AFFECTS BOTH
ODD & EVEN
SOLO RIGHT
SPEAKER
ON
MONITOR
OUT - R
COMMON
INPUT - L
COMMON
INPUT
LEVEL
ODD
MIX BUSES
1 3 5 7 9
11
2 4 6 8
10
12
EVEN
MIX BUSES
L
R
SOLO AND MONITOR CIRCUITS
HEADPHONE
JACK
COMMON
INPUT - R
COMMON INPUT CIRCUITRY

how to use this manual
format
This manual uses a format that is intended to be easy to read, yet technical for those
who need to know all the details. For feature descriptions, this is done by devoting the
left side of each page to 1) an overall module picture, 2) a block diagram, and 3) a con-
trol closeup.These images all pertain to the features and control descriptions on the
right side of the page.The intention is to make the manual easy to read while including
all the technical details needed for getting the most out of the X-Rack - a compact, flexi-
ble, feature-rich addition to Crest Audio's growing line of audio mixing console products.
conventions
Control Icons
This manual uses symbols to illustrate what the control descriptions are referring to.This
makes it possible to avoid redundant wording and makes the control descriptions clear.
Switch in the UP, non-activated position
Switch in DOWN, activated position
Switch that illuminates when in the DOWN position
Momentary switch that illuminates when activated
LED that is on, indicating that it's associated feature is activated
Potentiometer
Standard 1/4" TRS jack (used for line level inputs)
1/4" TRS jack with normal switching (used on inserts)
Female XLR input jack
Male XLR output jack
T= Send
R= Return
S= GND
T= IN +
R= IN –
S= GND
LED
p.5

Mono input channel
1
p.6
XRM owner’s manual
500500500500500500500500500500500
6
500
PFL
40
20
10 0
6
•
3
30
+
–
40
20
10 0
10
•
5
30
+
–
CHAN
LE VEL
0
1515
88
+–
0
1515
88
+–
0
1515
88
+–
0
1515
88
+–
LM
LF
HF
HM
EQ
ON 1
600
1K
2K 3K
8K
400
5K
300
500
1K
2K
100
MIX SENDS
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
SIG
PK
1
MUTE
GAIN
LO CUT
20
10
50
70
40
500500500
PRE
1
2
3
4
5
6
7
8
9
10
11
12
S
T
R
S
T
R
S
T
R
S
T
R
S
T
R
S
T
R
500500500500500500500500500500500
0
HF
500
F
500
LINE INPUT
(MIC PAD )
LO CUT
500500500
GAIN
20
10
50
70
40
BAL XLR
IN
BAL LINE IN
INPUT
PREAMP
GAIN
10 - 70 dB
HPF
LINE
(MIC PAD)
26dB
PA D
INSERT
SEND / RTN
+48V ON
HPF
70Hz
-18dB/Oct
I
N
SI
G
L
REAR PANEL
PEAK
(PFL)
SIG
PIN 1 LIFT
SPLIT
OUT
Module
Block diagram
Controls

Front panel features
Line Input (Mic Pad)
With this switch in the UP position, the input preamp circuit is set up to accept a mic-level
signal. This signal is brought in via the XLR mic-input connector located on the rear panel.The
1/4" TRS input jack is ignored.
When the switch is depressed, a Pad is inserted into the signal path and the input preamp
circuit is set up to accept a line-level signal from either the XLR mic-input connector or the 1/4"
TRS input jack, both located on the rear panel.The XLR signal is normal'd to the 1/4” TRS jack. If
nothing is plugged into the TRS jack, the XLR signal is fed to the preamp when the LINE switch is
pressed. Since the TRS signal is always padded down by 26dB, this feature allows the LINE switch
to act as a PAD switch for bringing a very hot microphone signals down to a controllable level,
avoiding overload.When a plug is inserted into the 1/4" TRS input jack, the XLR mic-input signal is
disconnected and the signal present on the 1/4” plug is fed to the preamp. If plugs are inserted
into both the XLR and TRS jacks, this switch acts as an input selector switch between the two
jacks.
Gain
The Input gain control is used to establish proper gain structure in the channel. For best
results, use the Solo system to monitor the channel while you set the gain.The goal is maximum
gain without distortion. Both the main LED meters (during Solo) and the channel’s Level/Peak
indicator can be used for adjusting gain.
70 Hz Lo-Cut filter
This filter reduces or eliminates unwanted low frequencies without substantially affecting the pro-
gram material. Quite often, such unwanted low frequencies are included with mic- or line-input
signals. For example, stage rumble or wind can be picked up through vocal mics.The cut-off fre-
quency of the filter is 70 Hz and the slope is -18dB per octave.This type of filter is also referred
to as a Hi-pass filter (HPF). It allows the hi-frequencies to pass, but stops the lo-frequencies.
Lo Cut Switch
Lo-Cut filter is bypassed.
Lo-Cut filter is on.
Mono Input channel 1
p.7

Mono input channel
1
p.8
XRM owner’s manual
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4
2
3
2
3
6
0
1
3
0
500
2
3
2
3
2
3
2
3
2
3
2
3
4
2
3
4
2
3
4
2
3
4
2
3
4
2
3
PFL
40
20
10 0
6
•
3
30
+
–
40
20
10 0
10
•
5
30
+
–
CHAN
LE VEL
0
1515
88
+–
0
1515
88
+–
0
1515
88
+–
0
1515
88
+–
LM
LF
HF
HM
EQ
ON 1
600
1K
2K 3K
8K
400
5K
300
500
1K
2K
100
MIX SENDS
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
SIG
PK
1
MUTE
GAIN
LO CUT
20
10
50
70
40
500500500
PRE
1
2
3
4
5
6
7
8
9
10
11
12
S
T
R
S
T
R
S
T
R
S
T
R
S
T
R
S
T
R
500500500500500500500500500500500
8
8
8
8
6
0
1
3
0
500
0
1515
88
+–
0
1515
88
+–
0
1515
88
+–
0
1515
88
+–
LM
LF
HF
HM
EQ
ON 1
600
1K
2K 3K
8K
400
5K
300
500
1K
2K
100
MIX SENDS
LO CUT
10 70
500500500
PRE
FOUR BAND EQ
LEVEL
LF LOW MID HI MID HF
M
EQ ON
XRM MONO INPUT MODULE
12 MONO INPUTS AVAILABLE
FREQ LEVEL LEVELFREQ LEVEL
12 KHZ400 - 8 KHZ80 - 2 KHZ80 HZ
CHAN
FADER
Module
Block diagram
Controls

Front panel features
Equalizer (EQ)
Many audio signals coming into the console require some degree of corrective eq in order to be
part of a good sounding mix. XRM offers a 4-Band EQ on each channel.The input EQ consists of
the bands: High, High-Mid, Low-Mid and Low.The High and Low frequency bands are shelving
equalizers, each have a boost/cut control and their frequencies are fixed.The High-Mid and Low-
Mid bands have a bell-shaped response, each band features variable boost/cut and adjustable fre-
quency.
high frequency—HF
Boost / Cut 15dB boost and cut. Shelving @ 12 kHz
high mid—HM
Frequency Continuously variable between 400 Hz and 8 kHz.
Boost / Cut 15dB boost and cut. Bell curve with a BW of approx 1.5 octaves
Low mid—LM
Frequency Continuously variable between 100 Hz and 2 kHz.
Boost / Cut 15dB boost and cut. Bell curve with a BW of approx 1.5 octaves
Low frequency—LF
Boost / Cut 15dB boost and cut. Shelving @ 80 Hz.
EQ on
Equalizer is OFF. The equalizer circuitry is bypassed.
Equalizer is ON. This switch is used to activate the EQ section and can be used to make
A/B comparisons between "flat" and eq'd signals.
p.9
Mono Input channel 1

p.10
Mono input channel
1XRM owner’s manual
500500500500500500500500500500500
4
2
3
2
3
6
0
1
3
0
500
2
3
2
3
2
3
2
3
2
3
2
3
4
2
3
4
2
3
4
2
3
4
2
3
4
2
3
PFL
40
20
10 0
6
•
3
30
+
–
40
20
10 0
10
•
5
30
+
–
CHAN
LE VEL
0
1515
88
+–
0
1515
88
+–
0
1515
88
+–
0
1515
88
+–
LM
LF
HF
HM
EQ
ON 1
600
1K
2K 3K
8K
400
5K
300
500
1K
2K
100
MIX SENDS
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
SIG
PK
1
MUTE
GAIN
LO CUT
20
10
50
70
40
500500500
PRE
1
2
3
4
5
6
7
8
9
10
11
12
S
T
R
S
T
R
S
T
R
S
T
R
S
T
R
S
T
R
500500500500500500500500500500500
4
2
3
500
2
3
2
3
2
3
2
3
2
3
2
3
4
2
3
4
2
3
4
2
3
4
2
3
4
2
3
40
20
10 0
6
•
3
30
+
–
ON
500
MIX SENDS
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
40
20
10 0
6
•
3
30
+
–
MUTE
500500500
PRE
1
2
3
4
5
6
7
8
9
10
11
12
S
T
R
S
T
R
S
T
R
S
T
R
S
T
R
S
T
R
HF
PRE-SOURCE
SELECT
PRE
SOURCE
MUTE ?
SOLO DC
+10
MUTE
EQ ON
FADER AMP
PRE-SOURCE
BUFFER
NO
YES
SOLO LEFT
R
C
4
U
LE
E
L
EVEL
SOLO RIGHT
12 KHZ
PFL
CHAN
FADER
MIX 1-4
PRE
PRE
FADER
PRE
EQ
PRE
INSERT
TO
PEAK
CIRCUIT
M1
M2
MIX SENDS 1 & 2
LEV / LEV
__
LEV / PAN
SWITCHING
M3
M4
MIX SENDS 3 & 4
LEV / LEV
__
LEV / PAN
SWITCHING
M5
M6
MIX SENDS 5 & 6
LEV / LEV
__
LEV / PAN
SWITCHING
M7
M8
MIX SENDS 7 & 8
LEV / LEV
__
LEV / PAN
SWITCHING
M9
M10
MIX SENDS 9 & 10
LEV / LEV
__
LEV / PAN
SWITCHING
M11
M12
MIX SENDS 11 & 12
LEV / LEV
__
LEV / PAN
SWITCHING
Module
Block diagram
Chan SendsChan Fader
500500500500500500500500500500500500
PFL
40
20
10 0
10
•
5
30
+
–
CHAN
LEVEL
500
40
20
6
•
3
30
+
40
20
10 0
6
•
3
30
+
–
SIG
PK
1
MUTE
500500500
12
S
T
R
SOLO PWR COMMON
I
NPUT
M
L
F
M
4
500500
5
10
0
5
10
20
30
SIG
PK
1
AFL
234
OUTPUT MASTERS
STR PAIR LO CUT STR PAIR LO CUT
1–23
–4
STR PA R O CUT STR PA R O CUT
500500500500500500500500500500500 500500500
1
2
S
T
R
Master Faders