Connection | en
The L1 or L2 audio inputs allow to connect local audio sources, e.g. in stand-alone mode. The
audio signal L1 is mixed with input signal LINE IN 4 (provided via RJ-45) and amplified by
amplifier output channel 1. Audio signal L2 is mixed with input signal LINE IN 4 and amplified
by amplifier output channel 2.
If local audio sources should be used while full system supervision is required, a pilot tone
must be available at LINE IN 4. Please refer to section Circuit diagram, page 32 and the
documentation of IRIS-Net.
The audio inputs are electronically balanced. You must always use a balanced audio signal at
the input of the device where this is possible. The scope of delivery for the device includes a
3-pin connector. Conductor cross-sections of 0.14 mm² (AWG26) to 1.5 mm² (AWG16) can be
Recommended connecting cable: balanced cable with shielded flexible 2 x 0.14 mm².
The following illustration shows the balanced cabling of an audio input (or output) on the
Figure 6.2: Balanced cabling
If the connecting cable(s) is/are very short and no interference signals are to be expected in
the environment of the device, then an unbalanced signal can also be connected. In this case,
it is imperative that a bridge in the connector between the shield and the inverting pin is
switched (see diagram below), otherwise the level can drop by 6 dB. However, for reasons of
immunity to external interference sources such as dimmers, mains supplies, HF control lines
etc., balanced cabling is always preferable.
18-Jun-2015 | 04 | F01U306898