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 |
|
| C.S.A. OF EACH |
| CABLE | % POWER LOSS | % POWER LOSS |
|
|
|
| |||||
| (m) |
|
| CONDUCTOR (mm) |
| RESISTANCE Ω | INTO 8Ω LOAD | INTO 4Ω LOAD |
10 |
| 2.5 |
| 0.14 | 1.7 | 3.5 | ||
|
|
| 4.0 |
| 0.09 | 1.1 | 2.2 | |
|
|
| 6.0 |
| 0.06 | 0.73 | 1.5 | |
25 |
| 2.5 |
| 0.35 | 4.3 | 8.6 | ||
|
|
| 4.0 |
| 0.22 | 2.7 | 5.4 | |
|
|
| 6.0 |
| 0.14 | 1.8 | 3.6 | |
50 |
| 2.5 |
| 0.69 | 8.6 | 17.0 | ||
|
|
| 4.0 |
| 0.43 | 5.4 | 11.0 | |
|
|
| 6.0 |
| 0.29 | 3.6 | 7.2 | |
100 |
| 2.5 |
| 1.38 | 17.0 | 35.0 | ||
|
|
| 4.0 |
| 0.86 | 11.0 | 22.0 | |
|
|
| 6.0 |
| 0.58 | 7.2 | 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 of 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 compressor/limiter or active crossover is being used with multiple cabinets; it is therefore recommended that the same amplifiers be used throughout.
5. Operation
For optimal performance, the iQ 10 has been designed to operate in conjunction with the Tannoy TDX1 & TDX2 System Controllers, and iQ 18B bass unit for extended bass performance. The TDX controllers have been factory preset to provide the recommended eq, crossover points, and overall system balance. Please refer to the TDX1 & TDX2 manual for operation.
If you intend using an alternative loudspeaker management system (e.g. BSS™, KlarkTeknik™, XTA™ etc) please refer to section 12 of this manual.
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