Tannoy B400, Руководство пользователя, Страница: 5 / 13

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 complete range of Tannoy Professional contractor products can be used in
conjunction with the B400 utilising TX1, TX2 & TX3 crossover/controllers (see
product literature for correct TX controller)
For active operation the TDX1 digital loudspeaker management system is also
available (late ’98). If you intend using an alternative loudspeaker management
system (i.e. BSS

, Klark Teknik

, XTA

etc) please contact Tannoy for the correct
parameter settings or refer to the recommended crossover points in the technical
specifications section of this manual. Ideally the crossover should have limiters and
have the capability to invert the polarity of the low frequency section if used with the
B400 enclosure.
Important : always invert the B400 polarity if used with standard reflex loaded
loudspeakers
7. Equalisation
The B400 loudspeaker is designed to need no equalisation or correction to overcome
system limitations. As a result, it 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. Violent equalisation will be detrimental to the overall
sound quality.