C l e a r l y b e t t e r s o u n d
Performance Graphs
Music Crosstalk
Sweep
Trace Line Style
Thick
Data
Axis
Comment
1
1
Dot
1
Anlr.Ampl
Left
Crosstalk, Adjacent Line Inputs
2
1
Solid
1
Anlr.Ampl
Left
Crosstalk Between Outputs
Note that the crosstalk was not measured using bandpass techniques. It is below the noise floor
between zone outputs and between line inputs below 1kHz.
-120
+0
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
d
B
u
20
20k
50
100
200
500
1k
2k
5k
10k
Hz
Music Frequency Response
-3
+3
-2.5
-2
-1.5
-1
-0.5
-0
+0.5
+1
+1.5
+2
+2.5
d
B
u
20
20k
50
100
200
500
1k
2k
5k
10k
Hz
Z4
MK4
/Z8
MK4
Music Crosstalk
Z4
MK4
/Z8
MK4
Music Output Frequency Response
Architect’s and Engineer’s Specification
The mixer shall be available in two versions, with four or eight electronically
balanced mono outputs (zones) on rear panel multipin connectors respectively.
Unless otherwise stated, all specifications which follow shall apply to both
versions, with the two versions differing only in those facilities specific to the
outputs.
The mixers shall be equipped with two unbalanced stereo music inputs on
phono sockets (RCA jacks), four balanced stereo music inputs on plug-in
screw-terminal connectors and three electronically balanced microphone
inputs on plug-in screw terminal connectors. All inputs shall be on the rear
of the mixer. One of the microphone inputs shall be configured specifically to
operate with paging microphones.
The music input to each zone and the music level in the zone shall be
adjustable by front panel controls. Each zone shall also have its own front panel
microphone level controls, one per microphone input. The level control for the
paging microphone input shall be of the preset type and recessed behind the
panel. It shall be possible to control the level of the music source independently
of the microphone levels in each zone.
Each music input shall have a rear panel input gain trim control with a range of
at least 20 dB. Two-band equalisation adjustment shall be provided on the rear
panel for the music signal in each zone. Two-band equalisation adjustment shall
also be available for each microphone input; phantom power shall be available at
any or all microphone inputs when selected by internal DIP switch.
It shall be possible to connect a compatible paging microphone to the mixer
using a single Cat 5 cable; an RJ45 connector shall be provided for this purpose.
The port shall carry audio, zone selection data and power for the microphone.
A second RJ45 port shall enable a second mixer to be connected such that
microphones able to page a greater number of zones than the mixer can
support may be able to do so via the use of the second mixer. The mixer shall
be provided with a second method of paging, in the form of a control input to
activate the paging microphone input by external contact closure, and route
its signal to any or all zones, replacing the music signal while the contacts are
closed.
It shall be possible to configure the mixer to perform the following functions:
i) detection of a signal on either non-paging microphone input will automatically
reduce the music level by 30 dB, ii) detection of a signal on the paging
microphone input will automatically route the signal to all zones, iii) one line
input will automatically override all others in all zones, even if unselected.
Optional remote control panels shall be available to permit control of i) music
level in any zone; ii) music source selection and music level in any mixer channel;
it shall be possible to retrofit these to the mixer at any time. The remote control
panels shall connect via a rear panel plug-in screw-terminal connector. It shall
be possible to disable either the front panel music level or the music level and
music source selection controls by moving internal jumpers.
An external control input shall be provided to allow muting of the music source
by a fire alarm or other external emergency system via isolated, ‘volt-free’
contacts, and this input shall be configurable to respond to either a short or
open external circuit. Front panel LED indication of the muting action shall be
provided.
Each zone output shall be provided with an additional balanced input on a
multipin connector; this input shall route audio only to its own zone. An optional
input plate shall be available to allow the connection of external microphone
and line level audio sources at a remote location, and this plate shall connect to
the mixer via the multipin connector, which also shall supply DC power and all
necessary control interface connections. The remote input plate shall allow the
connection of one microphone and one stereo line level input, with individual
level controls for each input, and sum the inputs. Controls shall also be provided
for music source selection and music level in the zone to which it is connected.
It shall be possible to enable the mixer’s music ducking facility from the plate.
The mixer shall accept internal plug-in equaliser cards to permit use with
compatible loudspeakers. It shall be possible to fit these in any or all of the
zone outputs.
The mixer shall be built in a 3U steel chassis for mounting in a standard 19” rack.
The mixer will operate from any AC mains supply voltage between 85 V and
253 V. The mains supply shall be connected via a detachable IEC cable and there
shall be a front-panel LED which illuminates when AC mains power is connected.
The mixers shall be the Cloud Z4
MK4
(four output zones) and the Cloud
Z8
MK4
(eight output zones); the optional remote control panels shall be the
Cloud RL- 1 Series (music level only) and the Cloud RSL-6 Series (music level
and source selection). The optional remote input plate shall be the Cloud LM-2.
