XTA DC1048 - Manual (Page 48)

Page 48 DC1048 Integrated Audio Management Operator’s Manual
Setting Accurate Limiter Thresholds
The limiters in the DC1048 are intended to be used for loudspeaker driver
protection, as opposed to amplifier protection. All modern professional power
amplifiers designed for live sound use have their own limiters, which are tailored
to protecting the amplifier from clipping. The following section describes how to
set up the units’ limiters to provide exceptional protection against driver
overheating, and cone over-excursion.
Most speaker systems are given a power rating in Watts RMS. This is the
maximum continuous power that the system will handle and often appears very
conservative. In reality, as music program is far from continuous in nature, the
peak power of the system is much higher – up to ten times the continuous figure.
Any limiter, which is to protect the driver from damage, must be able to fulfil the
following tasks.
Have an attack time, which is calculated to allow transients through but
keep the RMS level below the speaker manufacturers specification;
Have a release time, which is sufficiently long to avoid the limiter itself
modulating the program;
Be intelligent enough to adjust the envelope of the limiter according to the
frequency content of the program material.