Wiring And Connections; Connector Type; Low-Impedance Mode - Tannoy VLS 7 Operation Manual

5. Wiring and connections

5. Wiring and connections

5.1 Connector type

Each VLS Series loudspeaker is equipped with a pair of internally paralleled barrier strip terminals for connection
to the amplifier (or to other loudspeakers in a 70/100 V system or series/parallel configuration). Barrier strips
accept wire up to 4 mm sq CSA (AWG 12). Barrier strip polarity is as indicated.

5.2 Low-impedance mode

If connecting directly to the amplifier in low-impedance mode, connect the positive (+) conductor to a positive
(+) barrier strip terminal and the negative (-) conductor to a negative (-) terminal. Several loudspeakers may
be connected to one amplifier output in parallel, series, or series/parallel configurations using the other
internally paralleled barrier strip connector. Please refer to following section on series/parallel configuration
before connecting.
When choosing cable type, it is important to select the correct cross sectional area in relation to the cable
length and the load impedance. A small cross sectional area will increase the cable's series resistance, inducing
power loss and response variations (damping factor). Connectors wired with 2.5 sq. mm (12 AWG) cable will
be
satisfactory under normal conditions; with very long cable runs, the wire size should be increased. Please
refer to the following table for guidance:
Cable Run C.S.A.of
(m)
conductor
10
25
50
100
Amplifier selection - As with all professional loudspeaker systems, the power handling is a function of voice
coil thermal capacity. Care should be taken to avoid overdriving the amplifier into clipping. Damage to the
loudspeaker will be sustained if the amplifier is driven into clipping for any extended period of time. Headroom
of at least 3 dB should be allowed. When evaluating an amplifier, it is important to take into account its
behaviour under low impedance load conditions. A loudspeaker system is highly reactive, and with transient
signals it can require more current than the nominal impedance would indicate. Generally a higher power
amplifier running free of distortion will do less damage to the loudspeaker than a lower power amplifier that
6
VLS Series Operation Manual rev 1.1.0
AWG
each resistance
(mm )
2
2.5 13
4 11
6 9
2.5 13
4 11
6 9
2.5 13
4 11
6 9
2.5 13
4 11
6 9
Cable % Power dB loss into
loss into 4 ohm load
ohms 4 ohm load
0.13 3.9
0.08 2.5
0.05 1.6
0.33 9.3
0.21 6.1
0.13 3.9
0.66 17.0
0.41 11.4
0.26 7.5
1.31 29.1
0.83 20.5
0.52 14.0
% Power dB loss into
loss into 4 ohm load
8 ohm load
0.17 2.0
0.11 1.3
0.07 0.8
0.42 4.9
0.27 3.1
0.17 2.0
0.81 9.3
0.53 6.1
0.34 3.9
1.49 17.0
1.00 11.4
0.65 7.5
0.09
0.06
0.04
0.22
0.14
0.09
0.42
0.27
0.17
0.81
0.53
0.34