Inter-m microphone Installation and operating instructions

Installation Advice & Information
All microphones, as standard, are dynamic
(electret versions are available to special
order) and feature non-latching PTT (Press-
to-Talk) buttons which mute the microphone
until pressed. When released the muted state
is restored automatically making accidental
broadcasts all but impossible. The same
button also produces a ‘clean contact closure’
when pressed which can be used to activate
electronic access, chimes or to control paging-
only zones.
Where electret microphones are used, these
require a DC voltage 12v minimum to operate.
This can be supplied down the microphone
cable by the host amplifier if it is capable of
providing ‘Phantom Power’.
Phantom Power
Phantom Power is a method of providing a
voltage at very low current specifically for
this type of microphone. It is not normally
capable of providing sufficient current to power
line-amplifiers and damage to the amplifier may
result if the facility is not used correctly.
Some notes on cable requirements
As the output level of microphones is very low
(from 0.5 to 5mV) it is absolutely essential that
good quality twin-screened microphone cable
is used connected as a balanced circuit. No
system will operate correctly or reliably if wired
in any other manner.
Where the distance between the microphone
and amplifier is greater than 50m, it is advisable
to consider the inclusion of a line amplifier to
compensate for signal loss down the cable. With
a cable length in excess of 100m, a line amplifier
should be considered essential.
Remember, a line amplifier needs DC power
(usually 24v), preferably derived at the amplifier
location. This requires an additional pair of wires
where power is not required for other facilities.
CIE-Group stock a suitable cable (West Penn
357). Local powering is possible but should
only be used as a last resort as, if the supply
is unplugged or switched off, the system will
not operate.
Where additional cables are used for controlling
relays and providing power, it is often more
economical to install a separate multi-core cable
as screening is not required. Twisted pair cable
is desirable and the wise installer allows a few
extra pairs to cater for future expansion.
Single-Zone Microphones
These usually address the entire system as a
single-zone, however it is possible to divide a
system which has music into two-zones. One
with paging and music and one which carries
the paging announcements only by using a
ZRU102 configured as a Music Paging
Selector.
Actual choice of microphone depends on the
distance between the microphone and amplifier
and the sophistication required.
BUD100 is a simple yet robust unit featuring
a gooseneck-mounted microphone well
known for its voice clarity in almost any
operating environment and made in the UK by
Communication Technology.
DPM102/B is a more sophisticated pre-amplifier
with a built-in limiter and progressive bass cut
for improved intelligibility with other optional
facilities.
Multiple-Zone Microphones
As standard, 2/5/10 zone formats are available.
Systems requiring more than 10-zones can
be manufactured to special order (quotations
available on request).
2-Zone
Either a BUD200 or DPM202/B microphone can
be used with the ZRU102 loudspeaker routing
and paging selector to create a versatile 2-zone
system.
Up to 5-zones & 10-Zones
Two methods can be employed depending on
the sophistication required.
The simpler of the two utilises the ZSU-5, part
of the ‘Clever Little Box’ range, to switch 100v
speaker lines and either DM105/CT or DM110/
CT microphones. ZSU-5 is a 5-zone relay
selector where two or more units can be slaved
together to create larger systems. A number of
microphones can be connected with the zone
selection on each being independent of all the
others. Note that a separate input is required
for each microphone on the system. Music
selection is also possible. Full details of the
various applications are contained in the ZSU-5
specification sheet.
The importance of the microphone on the
reception desk is all too often wrongly under
estimated. It is, in reality, a vitally important
component in any sound system as the quality
and intelligibility of the output of any PA system
can self-evidently not be better than what goes
in. ‘Garbage in, equals garbage out’, so the
quality of the microphone dictates the overall
sound quality of the whole system.
Several major factors need to be considered in
the design of desk paging microphones:
•The frequency response needs to be flat
over the speech band without emphasising
low frequencies.
•The polar diagram (area of coverage)
needs to be carefully tailored to avoid picking
up unwanted background noise and
conversation.
•The mechanical construction must be very
robust as paging microphones have a hard
life and have the potential to generate more
service calls than almost any other PA system
component.
•‘Press-to-Talk’ switches need to be
exceptionally robust and non-latching.
In partnership with Communication Technology,
CIE-Group offer a wide range of quality paging
microphone solutions in both single and multiple
zone formats.
Paging Microphones can be divided into two
groups; single zone and multiple zone. For the
multi-zones we offer two ranges of microphones;
‘Buddy’ simple yet effective or ‘Pro Series’ which
is more sophisticated, in addition to specialist
types such as vandal resistant and store-and-
forward.
www.inter-m.uk.com

Pro-range Multi-zone, Multi-point,
Zone Paging System
These dedicated 5/10-zone self-cancelling
paging points operate exclusively with a
rack-mounting ZRU010 relay interface and
central logic processor for up to 10 zones.
ZRU010 processors can be cascaded to create
larger systems. Up to 8 paging points can be
operated by a single ZRU010.
Whilst most system designers will switch zones of
loudspeakers, the system is sufficiently versatile
to operate between pre-amplifiers, 600Wsignal
sources or with individual zone amplifiers. Each
paging point incorporates audio compression;
an in-built pre-announcement ‘gong’ is a link
selectable option.
Audio and data communication between the
ZRU010 central processor and each paging
point uses standard CAT5 technology and
cabling.
Operations of the ‘Press-to-Talk’ button activate
the zone relays. After release, and on completion
of the page, the system is automatically returned
to default ‘All-Call’ state. The operator does
not have to remember to cancel the zone(s)
selected.
Provision is made to connect a dedicated music
amplifier and a separate paging amplifier. When
a system is configured this way, paging into
individual zones will not disturb the distribution
of music to others. Full specifications and
configuration details are contained in the
product application notes.
Gooseneck Microphones
For many years the speciality of Communication
Technology, the UK-designed range now
comprises dynamic and electret gooseneck
microphones in lengths up to 420mm with or
without XLR terminations and rugged heavy duty
versions for such applications as buses, cranes,
transport termini and supermarket check-outs.
Wall Microphones
The most common of these more specialised
types is the wall plate mounted microphone.
Designed to be flush-mounted into a wall, they
are very useful where a microphone is required at
(for example) a security gate or building entrance
but can also be used in industrial applications
where a heavy duty unit is desirable.
Most (but not all) are intended to be mounted in
a standard twin-gang 25mm deep electrical box
and are weather resistant for use outdoors.
The more robust types are designed to withstand
a high degree of misuse or deliberate vandalism.
This usually includes stainless steel front plates,
microphone grilles and heavy duty PTT switches
as in the Pro-Series.
Store & Forward Microphones
Acoustic feedback (howl round) has always
been an issue with public address systems.
Digital technology has now provided the answer
in ‘store-and-forward’ technology. The idea is
simple; record the message into a digital store
which holds the message until the press-to-talk
switch is released.
As the message is not sent out in real time (i.e.
when the microphone is active), any possibility
of feedback is eliminated.
In addition, the inclusion of a storage facility
opens up other possibilities; these include
message screening and more interestingly, the
prospect of storing announcements that are
required on a regular basis. Up to 3 messages
can be stored with a total capacity of 2 minutes.
Messages are user recordable and can be sent
out manually on demand or on a timed basis, the
interval being set on the microphone. It should
be noted that this type of unit is not suitable
for use as the primary microphone in voice
evacuation systems.
www.inter-m.uk.com