Tannoy VQ 60 User Manual page 6

Barrier Strip Connections
The barrier strip accommodates bare wire, tinned leads or spade connectors. The barrier strips are specifically
designed for utilization in fixed/permanent installations. The VQ 60 and VQ 100 are configured for Bi-amp
operation; by removing the 4 link wires between the two barrier strips on the termination panel tri-amp operation is
possible. The VQ DF is configured for single amp operation; by removing the 4 link wires between the two barrier
strips on the termination panel bi-amp operation is possible.
.
VQ 60/100 Bi-amp –
VQ 60/100 Tri-amp -
VQ DF Single Amp -
VQ DF Bi-amp -
VQ MB -
Note that looping out to additional loudspeakers will have the effect of reducing the load on the amplifier. Avoid
loading amplifiers too low. If the amplifier is rated for 4 ohms minimum, don't give it a 2 ohm load. Even when the
amplifier is rated down to 2 ohms remember that in order to keep up with the power the circuit will have much
higher current than before and the wiring will have to handle it. Not only will the wiring losses grow but the
damping factor of the system will be degraded. It might be better to run separate cables from the amp to the
speakers or divide the load across two amplifier channels.
Cable choice consists mainly of selecting the correct cross sectional area in relation to the cable length and the
load impedance. A small cross sectional area would increase the cables series resistance, inducing power loss,
and response variations (damping factor).
Connectors should be wired with a minimum of 2.5 sq. mm (12 gauge) cable. This will be perfectly satisfactory
under normal conditions. In the case of very long cable runs the wire size should exceed this. The following table
shows the change in resistance, sensitivity loss and damping factor due to the effects of cable diameter and
length for two nominal impedance loads (4ohms & 8ohms). Use this table to determine a suitable cable diameter
for the length of run you require. For resultant damping factor, values greater than 20 are generally considered
adequate for high quality sound reinforcement systems.
Cable Run
m ft
1.5mm
2.5mm
5 16
1.5mm
2.5mm
10 33
1.5mm
2.5mm
25 82
1.5mm
2.5mm
50 164
1.5mm
2.5mm
100 328
*The resulting damping factor figures are derived using a good quality professional amplifier
6
Connect LF amplifier to LF +/- on top row of barrier strip.
Connect MF/HF amplifier to MF/HF +/- on bottom row of barrier strip.
Connect LF amplifier to LF +/- on top row of barrier strip.
Connect MF amplifier to MF +/- on top row of barrier strip.
Connect HF amplifier to HF +/- on top row of barrier strip.
Connect MF/HF amplifier to MF/HF +/- on bottom row of barrier strip.
Connect MF amplifier to MF +/- on top row of barrier strip.
Connect HF amplifier to HF +/- on top row of barrier strip.
Connect amplifier to LF +/- terminals
Diameter of
Cable
Resistance
conductor
mm awg ohm
15 0.10
10 0.04
4mm 6 0.01
6mm 3 0.01
15 0.20
10 0.07
4mm 6 0.03
6mm 3 0.01
15 0.49
10 0.18
4mm 6 0.07
6mm 3 0.03
15 0.98
10 0.35
4mm 6 0.14
6mm 3 0.06
15 1.95
10 0.70
4mm 6 0.27
6mm 3 0.12
Wire Loss (dB) Damping Factor*
4ohm 8ohm 4ohm
Load Load Load
0.2 0.1
40
0.1 0
108
0 0
255
0 0
494
0.4 0.2
19
0.2 0.1
55
0.1 0
136
0 0
282
1 0.5
8
0.4 0.2
23
0.1 0.1
57
0.1 0
123
1.9 1
4
0.7 0.4
11
0.3 0.1
29
0.1 0.1
64
3.5 1.9
2
1.4 0.7
6
0.6 0.3
15
0.3 0.1
32
8ohm
Load
80
216
510
988
41
111
272
563
16
45
114
246
8
23
58
127
4
11
29
65