2N Lift emergency phone 2N LiftNet - Manual, 1446 v1.8.3 - Manual (Page 29)

Lift Cabin Audio Unit
– Universal
2.2
29
 Do not use this type of audio unit in a position other than mounted on a
sufficiently large board. The acoustic properties of an uninstalled audio
unit cannot be guaranteed.
Separate Microphone Mounting
If the microphone is separated (connected by cable) it has a 25×25 mm large board
with self-adhesive foil. This helps you mount it easily behind any hole in the panel (the
minimum hole diameter is 5 mm, or a group of smaller holes of the same total area).
Just glue the microphone directly onto the required place from behind (be sure to
degrease and clean the surface carefully before!).
Requirements
 The minimum distance between the loudspeaker and microphone
centres is 90 mm. A lower distance may lead to acoustic feedback. A greater
distance (within the available 1m cable) does not matter.
 Make sure that the glued-on microphone does not pick up (even
partially!) the acoustic pressure from the space behind the panel.
Such sensing might result in acoustic feedback since the loudspeaker strongly
radiates sound into the cavity.
Separate Loudspeaker Mounting
The loudspeaker is equipped with a cable and can be separated from the electronics
by simply sliding it out within the reach of the cables delivered (1m). This option is
useful where there is not enough space for the whole electronic equipment. Fit the
loudspeaker according to the instructions below:
 While gluing choose such procedures or adhesives that prevent membrane
damage by adhesives and volatile substances, or heat.
 We recommend you to keep the loudspeaker sealed to eliminate vibrations.
Frequently Asked Questions Concerning Loudspeaker

Is it possible to use a common loudspeaker for the communicator and floor
announcing machine?
No, it is not.

May I use a loudspeaker of my own?
Yes, but make sure that the impedance is 64 Ω. By doing this you assume
responsibility for sufficient volume and frequency range.

May I place the loudspeaker on the cabin ceiling?
This placement is not recommended.

May I use a longer cable with the loudspeaker?
Yes, but not with the microphone.