Crest Audio X-Eight HS User manual

owner’s manual
X-Eight HS and RT mixing consoles

X-Eight owner’s manual
HS block diagram
2
5
5
1
3
7
7

1
2
3
4
5
groups HS p. 41
groups RT p. 59
master HS p. 73
6
master RT p. 101
7
micro muting system p. 125
8
power supply p. 141
stereo inputs p. 25
mono inputs p. 7
table of contents

X-Eight owner’s manual
RT block diagram
OFF
SCL+
∑
Ø
1
+8
2 3 4
LINE 1 IN
L R L R L
R
L
LF
POST FADER CTRL
FDR
Σ
Σ Σ Σ
LR
MUTE SCENE SELECT
GC
P
2
4
6
6
1
7
7

how to use this manual
conventions
terms
indicators or controls employed on the X-Eight console
will appear as:TERMS
tasks
are broken down into steps 1
2
3
warnings
indicators
tips
see
see—references other sections of the manual containing
supplementary information on the current topic or a related issue
Prefered methods.
Helpful hints.
Feature insights.
+
Procedures not to attempt.
Issues or hazards to keep
in mind when operating
the equipment.
a
What to look
for on-screen.
Alerts, indicators, or
prompts that may appear.
®

p.6
X-Eight owner’s manual
mono input module
module panel
legend
block diagram
1

p.7
mono input module
features
phantom power—+48V
48 volts DC is applied to pins 2 and 3 on the mic-input XLR con-
nector. This option is used with condenser microphones and active direct
boxes that require an external DC voltage (phantom power) in order to
operate.
pad
The mic-input signal is attenuated by 20dB to prevent some signals
(e.g.kick drum or lead vocal) from overloading the preamp stage.The pad
is used to bring a hot mic-input signal down to a controllable level.The
20dB pad is not functional when the LINE switch is depressed.
line
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 disabled.
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 locat-
ed on the rear panel.
When a plug is inserted into the 1/4" TRS input jack, the XLR mic-input
connector is disabled.
polarity reverse—ø
This feature is used for correcting or minimizing polarity and phase relat-
ed errors. For example, occasionally a balanced input connection is
reverse-wired before it gets to the mixing console.This can happen in
microphones,or in snake line interfaces.By using the polarity reverse fea-
ture,this type of error can be corrected.
polarity inverted
polarity not inverted
If the channel peak
LED is illuminated,
first try lowering
the input gain control.
Only when this method is
unsuccessful should the pad
switch be engaged.
+
If the 48V phantom
power switch is
engaged, depressing this
switch disconnects phantom
power from the mic input
XLR.
+
1
When similar signals
from different chan-
nels are combined, phase
cancellations can occur.
Reversing the polarity of an
input signal often corrects
such phasing errors.
+
The 48V switch should
not be engaged when
using standard (dynamic)
microphones, or other
sources that do not use
phantom power.
a

p.8
X-Eight owner’s manual
mono input module
module panel
legend
block diagram
1

p.9
mono input module
features
gain
The Input gain control range is closely related to the status of the PAD
switch and the LINE switch. In order to establish proper gain structure in
the console,input gain settings must be set correctly.
LINE—switch-up PAD—switch-up
15 to 75dB of gain can be added the mic-input signal.
The impedance at the input XLR is 4kΩ.
LINE—switch-up PAD—switch-down
-5 to 55dB of gain can be added to the mic-input signal.
The impedance at the input XLR is 4kΩ.
LINE—switch-down PAD—switch-up or -down
-10 to 45dB of gain can be added the line-input signal.
The impedance at the input XLR and input 1/4"TRS is 20kΩ.
high-pass filter—HPF
Proper use of the high-pass filter reduces or eliminates unwanted low fre-
quencies without substantially affecting the program material.Quite often
such unwanted low frequencies are included with in-coming mic- or line-
input signals.For example,stage rumble or wind can be picked up through
vocal mics.The slope of the high-pass filter is 12dB per octave.
HPF
High-pass filter is on.
HPF—variable control
When the high-pass filter is on, this control selects a frequency
between 20Hz and 400Hz as the point where attenuation begins.
1
If the channel peak
LED is illuminated,
first try lowering
the input gain control.
Only when this method is
unsuccessful should the pad
switch be engaged.
+

1
p.10
X-Eight owner’s manual
mono input module
module
legend
block diagram panel

p.11
mono input module
EQ features
Many audio signals coming into the console require some degree of cor-
rective eq in order to be part of a good sounding mix.
The input eq consists of four-bands: high, high-mid, low-mid and low.
The high and low bands have fixed frequencies while the high-mid and low-
mid bands are sweepable, with their higher and lower frequencies over-
lapping adjacent bands.
high frequency—HF
15dB boost and cut at 12kHz—Shelving Response.
high-mid frequency—HM
15dB boost and cut.
Selectable frequency range of 400Hz to 8 kHz.
The response is bell-shaped with a fixed Q of 1.5
low-mid frequency—LM
15dB boost and cut.
Selectable frequency range of 80Hz to 2kHz.
The response is bell-shaped with a fixed Q of 1.5
low frequency—LF
15dB boost and cut at 80Hz.
The boost response is bell-shaped and the cut response is shelving.
eq on
Equalizer is on. This switch can be used to make A/B comparisons
between "flat" and eq'd signals.
1

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p.12
X-Eight owner’s manual
mono input module
module panel block diagram

p.13
mono input module
aux send features
Eight auxiliary AUX SENDS are available for creating individual output mixes.
These mixes can be used for driving effects processors,providing monitor
mixes, creating broadcast or alternate sound reinforcement mixes, or
other special requirements.
aux sends 1–8
These knobs adjust the amount of signal sent to the AUX buses.
Unity gain occurs at the zero setting. AUX 6and 8controls pan function
when selected for stereo operation.
aux 1–4,5/6 and 7/8 pre-fader—PRE
The default signal source for the AUX SENDS is post-fader.These switches
are used for selecting the pre-fader signal for their respective auxes.The
pre-fader signal is derived post-mute and post-eq.
see—internal jumper options
AUX SENDS are post-eq,post-mute,and post-fader.
AUX SENDS are post-eq,post-mute,and pre-fader.
aux stereo 5/6 and 7/8
The default configuration for AUX 5,6,7and 8is mono,as with AUX 1–4.
In situations where stereo-aux signals are required (such as driving stereo
in-ear monitors or effects processors),these switches reconfigure the AUX
SENDS to operate in stereo by changing the functions of the potentiometers.
AUXES are configured as individual mono sends.
AUXES are configured as level and pan for stereo operation.
1

1
p.14
X-Eight owner’s manual
mono input module
module panel block diagram

p.15
mono input module
bus assignment features
The Input bus assignment section offers considerable flexibility for creat-
ing what eventually becomes the main output mix. Such features as LCR,
GROUP PAN ON and eight-individual group assignments allow several
approaches to building the desired mix.All assignments are derived post-
fader,post-eq,and post-mute.
left-center-right—LCR
This feature is used to precisely position a signal in a sound system with a
center speaker cluster in addition to left and right clusters.The PAN control
becomes an integral part of how the input-signal is sent to the LEFT,CEN-
TER,and RIGHT outputs.
The post-fader signal is assigned to the LEFT,RIGHT,and MONO/CENTER
buses.Relative amounts of the signal fed to each bus is determined by the
position of the PAN control.
pan control
The pan control positions the signal within the stereo left/right field,
(or between left/center or center/right in LCR mode).The signal must be
assigned to either LCR or the L-R bus for the pan control to have any
affect.
see—left-center-right
safe preview—LED
Green steady
This means that the mute function is in safe-mode.If the channel is part
of a mute scene,it will not be activated when the scene is recalled.The
local mute function operates normally regardless of whether or not the
channel is in safe-mode.
Green flashing
The micro mute system is in edit-safe mode,and the channel is included
in the safe-scene.Pressing the local mute button will include or exclude
the mute from the safe-scene.
Pressing the edit-safe button in the micro channel section will remove the
console from edit-safe setup mode and save any changes that have been
made to the safe-scene. At this point,the green-LED will stop flashing.
The green-LED will light steadily if the channel is part of the safe-scene,or
extinguish if it is not part of the safe-scene.
LED
LED
1
When in safe-mode,
a channel will not
accept commands for any
external source.
Commands sent from the
master onboard processor
and any external MIDI
device will also be ignored.
+
green-LED status
flashing green
edit-safe mode
channel included in safe-scene
steady green
part of the safe-scene
no light
not part of the safe-scene
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p.16
X-Eight owner’s manual
mono input module
module panel block diagram

p.17
mono input module
bus assignment features
safe preview—LED
Red steady
This indicates that the mute has been activated by the micro mute sec-
tion and is part of the current mute scene.
Red flashing
This indicates that the micro mute system is in edit-preview mode and
the channel is part of the mute scene that is currently being created or
edited.Pressing the local mute button will include or exclude the channel
from the selected mute scene.
Pressing the edit-preview button (LED-off) in the micro mute section will
remove the console from edit-preview mode and save any changes that
have been made to the selected mute scene. At this point,the red-LED will
stop blinking.
The red-LED will light steadily if the channel is part of the active mute
scene,or extinguish if it is not part of the active mute scene.
see—microprocessor muting
mute
The Mute switch has three functions:
1It acts primarily as a local mute switch by activating and deactivating the
mute.When any mute is activated locally, it will remain muted until it is
deactivated locally regardless of whether or not the mute is part of the
safe-setor an activemutescene(or a mutescene that hasbeen made inac-
tive).
2It is used in creating and editing mute scenes when the micro-
processor mute section is in edit-preview mode.
3It is used for including and excluding the mute in the safe-set when the
microprocessor mute section is in edit-safe mode.
This switch is illuminated whenever the channel is muted.
see—microprocessor muting
write-in label
This label may be written on with a grease-marker,and later wiped clean
with a cloth moistened with isopropyl/rubbing alcohol.Masking tape may
also be placed on this surface,if desired.
LED
LED
1
red-LED status
flashing red
edit-preview mode
channel in mute scene
steady red
part of active mute scene
no light
not part of mute scene
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p.18
X-Eight owner’s manual
mono input module
module panel block diagram

p.19
mono input module
level meter features
level meter
Each input includes a five-segment LED meter
for visually monitoring signal levels.This is essential for setting up and main-
taining proper gain structure.
peak indicator—PK
The input signal is monitored at several points throughout the chan-
nel.These points are the mic preamp, the EQ stage and the fader stage.
Overloads at any of these stages will cause the red peak-LED to light.
Then the channel gain should reduced.
signal level LED’s
These three LED's light up at +8—yellow,0—green, and -6 dB—
green. This level range -6 to +8 is the optimum operating range.
Compressed or relatively constant signals should remain close to 0.
signal present indicator—SIG
This green-LED varies in brightness in response to signal levels
between -40 dB and -6 dB.
LED
LED
LED
LEDLEDLEDLEDLED
Occasional flashing of the
peak LED is acceptable,
but frequent flashes indi-
cate that channel levels
must be lowered.
®
1
If the channel peak
LED is illuminated,
first try lowering
the input gain control.
Only when this method is
unsuccessful should the pad
switch be engaged.
+

1
p.20
X-Eight owner’s manual
mono input module
module panel block diagram