Tannoy VS15 HL, User Manual

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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, refer to the following table for guidance:-
CABLE RUN (m) C.S.A. OF EACH
CONDUCTOR (mm) CABLE
RESISTANCE
Ω
% POWER LOSS
INTO 8
Ω LOAD
% POWER LOSS
INTO 4
Ω LOAD
10 2.5
4.0
6.0
0.14
0.09
0.06
1.7
1.1
0.73
3.5
2.2
1.5
25 2.5
4.0
6.0
0.35
0.22
0.14
4.3
2.7
1.8
8.6
5.4
3.6
50 2.5
4.0
6.0
0.69
0.43
0.29
8.6
5.4
3.6
17.0
11.0
7.2
100 2.5
4.0
6.0
1.38
0.86
0.58
17.0
11.0
7.2
35.0
22.0
14.0
4. Amplification & Power Handling
As with all professional loudspeaker systems, the power handling is a function of voice
coil thermal capacity. Care should be taken to avoid running the amplifier into clip
(clipping is the end result of overdriving any amplifier). Damage to the loudspeaker will
be sustained if the amplifier is driven into clip for any extended period of time.
Headroom of at least 3dB 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 from distortion will do less damage to
the loudspeaker than a lower power amplifier continually clipping. It is also worth
remembering that a high powered amplifier running at less than 90% of output power
generally sounds a lot better than a lower power amplifier running at 100%. An
amplifier with insufficient drive capability will not allow the full performance of the
loudspeaker to be realised.
It is important when using different manufacturers’ amplifiers in a single installation
that they have very closely matched gains, the variation should be less than +/- 0.5dB.
This precaution is important to the overall system balance when only a single active
crossover is being used with multiple cabinets; it is therefore recommended that the
same amplifiers be used throughout.