Klark Teknik HELIX DN9848E, Руководство оператора

Страница: 46 / 52

Application Notes
38
DN9848E is caused by the use of sigma-delta converters for both analogue-to-digital and digital-to
analogue conversion (the competitor unit uses a different method of digital-to-analogue conversion),
which allows the DN9848E to achieve its superior dynamic range.
In order to prevent driver failure, the competitor product’s limiter threshold needs to be reduced such
that the peak of the transient is at the same level as the threshold of the DN9848E’s look-ahead
limiter, with a major effect on efficiency of speaker systems, as the effect of reducing the limiter
threshold is to limit the amount of continuous output power available, which means more amplifiers
and more speaker cabinets to achieve the same SPL. In the example below the competing unit’s
limiter threshold has been reduced so that level of the transient peak matches the threshold of the
DN9848E’s limiter:
The limiter threshold of the competitor’s unit has been lowered to -10.0 dBu to avoid the risk of driver
damage from the initial transient, at the cost of greatly reducing the efficiency of the PA system. The
look-ahead capability of the DN9848E’s limiters allows the thresholds to be set at the levels required
to protect the loudspeaker drivers, without the need to be concerned about transients being passed
by the limiters. This allows the PA system performance to be maximised by safely exploiting the full
operational range of the loudspeaker drivers.