TOA Electronics i12 Speaker User Manual


 
5. 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 or the loudspeaker to be realised.
It is important when using different manufacturers amplifiers in a single installation that the 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 are used throughout.
6. Crossovers
The T12 and i12 are supplied as standard for passive operation via the internal crossover network.
If higher peak outputs are required then both models can be used in conjunction with the Tannoy
TX2 controller/crossover which provides high pass filtering and a degree of parametric
equalisation (see performance data section), as well as a fixed crossover point for use with sub-
bass loudspeakers.
7. Equalisation
The T12 and i12 loudspeakers are designed to need no equalisation or correction to overcome
system limitations. As a result, they will only need equalisation to compensate for difficult acoustic
environments.
Over equalisation can reduce system headroom, and introduce phase distortion resulting in
greater problems than cures. If equalisation is required then it should be applied gently and
smoothly. T12 and i12 loudspeakers are point source, phase coherent designs and violent
equalisation will be detrimental to the overall sound quality.