Soundcraft B400 BROCHURE

Production, on-air and OB faciliti

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adio production, live, and outside broadcast each

demand specific qualities in a mixing console, and
addressing these disciplines in a single desk requires
flexibility and uncompromised fidelity. The Soundcraft B400
takes these tasks in its stride while offering the additional
benefits of inherent reliability, serviceability and
Soundcraft’s unique experience in the field of broadcasting.
Based on the highly successful B800, the B400 delivers a
level of configurability unrivalled in its class. Input frames
can comprise any combination of Mono, Stereo and Stereo
Telco modules. 8 Mono or 4 Stereo Groups can be specified
while the individual Monitor, Communications and Stereo
Master Modules, fitted to the B400 as standard, offer a
range of facilities to satisfy the most demanding engineer.
Yet despite its specification, the B400 provides a budget­friendly solution for facilities of all sizes. And whatever role
you ask it to play, the B400 performs with the
professionalism Soundcraft customers around the world
have come to expect.

• 24, 32, 40, 48, 56-module frames

• 1 stereo and 3 mono auxes

• LED indication on all switches

• Wide variation in module audio and logic / control

functions via internal jumpers

• Stereo ISDN cleanfeed facilities via direct outputs

on Telco channels

• Versatile and highly configurable monitoring via

speakers and studio and guest headphones

• Limiters on master output

• Wide range of meterbridge options

• Balanced audio inputs and outputs throughout, on

XLRs and EDACs

• Balanced internal bussing

The Mono Input Module accepts mic or line signals, selected by
the LINE switch, from separate rear panel input XLR sockets. The
48V switch provides for mic phantom powering. All front panel
switches incorporate a status indication LED.

The rotary channel GAIN pot provides continuous variation from
+10dB to +72dB mic gain, and -10dB to +20dB line gain. The (ø)
switch reverses phase of the selected mic or line input, which
can be replaced with the desk oscillator by the TONE switch.

The Mono Input has a 3 band EQ with frequency sweepable HF
and MF, and fixed frequency LF sections. Each EQ level control
provides maximum 15dB cut or boost, the HF being internally
selectable bell or shelving response, and covering from 1kHz ­16kHz. The MF has centre frequency sweepable from 250Hz to
4kHz. The shelving LF section is fixed at 100Hz. The entire EQ
section is placed in circuit by the EQ switch.

A variable frequency high pass filter (HPF) is controlled by a
rotary pot, covering 32Hz to 500Hz, and has an anticlockwise
end stop click off position.

There are four auxiliary sends. AUX 1,2, and 3 are mono, while
AUX 4 is a stereo send with a dedicated PAN control. All four
auxiliaries feature rotary level pots, and are individually
switchable PRE/post fade. The AUX 1 pot can be switched into
the channel direct output circuit by the DIR switch; in this state
there is no output to the AUX 1 bus. The direct output then
follows the AUX 1 PRE/post switch, but the signal can also be
replaced by desk oscillator and talkback slate from the
Communications Module.

The PANorama pot positions the input signal within the main
stereo mix. When the PAN switch is lit, the pot also pans
between odd numbered groups (left) and even numbered groups
(right). The panned signal is routed via the five buttons at the
top of the channel strip to any combination of the four pairs of
groups (1-2, 3-4, 5-6, 7-8) and to the stereo master bus (ST).
The 100mm channel fader offers +10dB maximum gain.

The eight segment LED meter can be selected as pre fade or pre
EQ by an internal jumper and follows the direct output when
DIR is pressed. The PK LED monitors the signal at three points;
pre EQ, post EQ and post fade. An EXT MUTE LED is provided to
indicate when the channel has been remotely muted via the rear
panel D-sub connector. When the channel is ON and the fader is
open, this is used as a cough mute in mic mode. Also in mic
mode, when the fader is raised, the relevant monitors will be
muted or dimmed depending on the jumper settings. A relay
contact output pair for mic levels is also provided on D-sub
connector. The Fader Open control signal can be set via a jumper
to Rem Com on the Stereo Master fader. Monitor mutes will
therefore not be activated until the stereo master fader is open.

The console's cue system has two modes - if the CUE button is
depressed for less than half a second it latches electronically,
otherwise it will operate in momentary mode. If the channel fader
is down when the cue system is active, then the PFL signal will be
sent to the cue left and right busses, whatever the AFL/PFL
settings on the Monitor Module. When in AFL mode, this signal is
fed in stereo. The CUE button is (optionally) reset whenever the
channel fader is moved from the down position. If the CUE
button is pressed when the fader is raised, the AFL/PFL signal will
be selected according to the position of the AFL/PFL MASTER
switch on the Monitor Module. When the input is in line level
mode and the CUE switch is pressed, this will (optionally) trigger
the remote start/stop facility which has two sets of relay contacts,
available via the rear panel D-Sub connector. These relays can be
set to either latching or pulsed operation via internal jumpers,
enabling most types of machines to be remotely started and
stopped. When both CUE and ON are selected, the cue will
(optionally) automatically be cancelled and the signal will be live,
provided that the fader is already raised. If the fader is down, the
cue will only be cancelled when raised from its end position.

If the module input is switched to TONE the monitor mutes and
remotes (start/stop) are disabled.

The Stereo Line Input Module accepts two stereo
pairs via 4 input XLRs selected by the B input switch
(TLCO on the Telco Module). A phase reverse (ø)
switch affects the right channel only.

The status of the L and R buttons determines
whether the left and right input signals are treated
as a stereo pair, are switched to mono, or whether
either signal is routed to both sides of the stereo
channel bus. The TONE switch operates as on the
Mono Module.

The channel GAIN pot provides continuous control
covering -12dB to +12dB on both line inputs. The B
switch on the Stereo Input selects the second line,
whereas this is labelled TLCO on the Telco Module
which accepts a telephone input from an external
hybrid.

The EQ is 3 band with a sweepable MF section and a
separately switched high pass filter (12dB/Octave at
80Hz). The HF and LF shelving sections both offer
±15dB of cut and boost at 10kHz and 100Hz
respectively. The MF band features a ±15dB bell
response filter and sweepable centre frequencies
from 500Hz to 8kHz. An EQ in/out switch is
provided.

There are four auxiliary sends. AUX 1, 2 and 3 carry
a mono summed signal whereas AUX 4 is fed in
stereo. All four sends are controlled by individual
pots, and each is selectable pre or post fade. A
stereo channel direct output is on XLRs on the rear
panel, and is sent at unity gain from the Stereo
Input. The Stereo Telco Input has a separate level
control for the direct output, and can be switched
pre or post fade. A TB switch allows talkback from
the overbridge microphone XLR input to be routed
to the direct output. When in telco mode, and the
channel is routed to the stereo master, the direct
output sends a stereo clean feed signal consisting
of the stereo mix, minus the channel's input signal.
If not routed to the stereomaster, the signal at the
direct output will be the stereo mix. When switched
to telco, the function of the PRE button is disabled.

The dual-function BAL/PAN pot is used to trim the
stereo balance of the channel signal. The balance
control automatically becomes a pan control if
either or both the L or R switches are selected, and
at this point the PAN LED will illuminate.

The panned or balanced signal can be routed via
the five buttons at the top of the module, to any
combination of the four pairs of groups and the
stereo master bus. When the signal is routed to the
groups, the left side is routed to the odd numbered
groups, and the right side to the even numbered
groups.

The 100mm fader offers +10dB maximum gain. The
8-segment LED meter can be set to pre fade or
post fade by an internal jumper. The PEAK LED
monitors the signal at three points: pre EQ, post EQ,
and post fade.

The Stereo Input Module logic functions operate as
on the Mono Input Module in line mode, except
that the feed to the CUE bus is always in stereo. The
Stereo Telco Module operates the same in Line A
mode, however when the Telco Input is selected the
(pulsed or latching) start B relay is used as a
“divert” or “hybrid latch”. This is initially activated
from the CUE function to set up a call or remote
line with a clean feed return. Switching the channel
ON will maintain this relay closure, ensuring that
the line is held while the fader is opened. Closing
the fader will drop the line from the hybrid.

Mono Input
Module

Stereo and Telco
Input Modules

A fully featured Stereo Master Module is provided. Individual
PSU status LEDs offer constant visual confirmation for the
phantom, audio and logic voltage rails. The ON-AIR switch,
operated manually or via an opto-isolator circuit, is used to
close a set of relay contacts, for external signalisation; it also
disables oscillator and some talkback facilities on the
Communications Module.

The aux master controls are located on this module. Each
master has a rotary level pot and an AFL button to monitor
the after-fade listen signal via the cue system.

The Stereo Master insert can be switched in and out of the
signal path, though the signals are always available on the
insert send XLRs.

The limiter in the Master Module signal path offers a 4­position switch for threshold, 0.5ms or 10ms attack, and
release continuously variable from 200ms to 10 secs. An auto
release facility is also available, giving 1 sec release time with
a 2-stage release action.

The stereo output from the module is controlled via a stereo
master fader. A mute circuit, operated remotely, is positioned
after the fader. The PEAK LED monitors both L & R signals,
pre-fader, and illuminates if either comes within 6dB of
clipping.

A mono output is also available, jumper selectable pre or post
the limiter. This output has a rotary level control, offering up
to 0dB of gain, a mute circuit, and PFL. The signal is a mix of
the stereo master left and right signals, and is taken pre or
post fader, as determined by the PRE switch.

Stereo Master
Module

The Mono and Stereo Group Modules are almost
identical in operation, providing both Stereo
Return and Group Master facilities. The Stereo
Group offers greater packing density, and is more
suited to applications where groups are treated as
a stereo left-right pair.

Stereo Return

Stereo Return inputs via rear panel XLR sockets.
Alternatively, by depressing the BUS switch the
stereo return section will pick up signals from the 8
group output busses. (Feedback is avoided as no
group can route to itself.) PAN, LEVEL and MUTE
controls are provided.

The post mute stereo signal can be routed to the
stereo mix and / or the group. The GROUP and BUS
switches are interlocked such that the GROUP
switch is over-ridden if both are depressed at the
same time.

The Stereo Return cue facility operates in the same
manner as the cue facility on the input channels.

Group Master

The group insert can be switched in and out of the
signal path, and an internal switch sets pre or post­fade operation. Whether the insert is switched in or
not, the group signal always appears at the insert
send XLR.

The group mute section, placed immediately before
the fader, can be manually or remotely switched.
An LED is provided to indicate remote mute
activation.

A remote control facility for machine start is
available, via relay contacts which are closed when
the fader is raised.

The signal is sent to the group outputs (XLR on the
mono, EDAC or stereo group). The signal is also
passed to the PAN pot and then routed to the
stereo bus. The stereo group is fitted with a
BALance control, switchable to PAN, and an IMAGE
WIDTH control.

Feeds from the group to AUXes 1-4 are controlled
by four pots. Each is switchable to pre or post fade
operation.

The group cue system operates as on the Mono and
Stereo Input Modules.

Two level indicator LEDs are provided: the SP LED
illuminates when a signal is present on the group
mix bus, and the PEAK LED illuminates whenever
the output of the group mix amplifier or the post­fader signal comes within 6dB of clipping.

Mono and Stereo
Group Modules