Telex DOC02-DN9848, DN9848 Loudspeaker Processor specifications Application Notes

Application Notes

DN9848 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 DN9848 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 DN9848’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 DN9848’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 DN9848’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.

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