Danley DNA 10K4 User Manual Download Page 30

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Limiters

The DNA Pro includes three limiters in the output signal   path.   Please note that while the Limiters in
this product   offer   protection for   amplifiers and drivers, they can never   protect   from all possible
scenarios, therefore Danley Sound Labs is not responsible for   any damage which   might occur.

VX Limiter (Unique to DNA Pro series )

This is a peak-‐detecting signal limiter. The VX Mode parameter determines the style of limiter. When
Virtual Crossover (VX) mode is off, the limiter is controlled in a conventional manner; the only
controls being Threshold and Overshoot.

The Overshoot limiter prevents the signal from exceeding threshold during the attack phase of the
main limiter by more than a predetermined amount. The optimal Overshoot setting is usually about
8dB. Lower Overshoot settings will sound progressively ‘harder’.

When VX mode is engaged, the user can choose the crossover point of a ‘virtual crossover’, which
incorporates two limiters per   output   so the user can individually limit the drivers in a passive 2-‐way
enclosure using individual thresholds, and optimised attack   and release characteristics   for each. The
Threshold of the second ‘Hi’   limiter is set relative to the threshold of   the first   ‘Lo’   limiter.

The effect of the VX threshold and split frequency on the Limiter curve can be seen in PodWare.

This Limiter introduces some delay. In non-‐VX mode, this delay will depend   on   the lowest high-‐pass
frequency used in the crossover   filters in a given Drive Module. In VX mode, the delay is related to
the Split   frequency.   This delay will   be applied to all   of the outputs in a given Drive Module to keep
them in phase.

Also see

Latency Delays

Tmax Thermal Limiter

The Thermal Limiter is intended to protect the driver against damage due to over-‐heating. It models
the temperature of   the driver, and constrains the output   signal level in order   to keep the average
output power below a predetermined   limit, applying attack and   release characteristics to   go   some
way towards modelling the complex thermal circuit of a   driver’s voice   coil and magnet assembly.
Three parameters are available for adjustment:
Threshold – the continuous RMS voltage which the driver   should be able to withstand. This is
calibrated at the output of the amplifier. The Thermal Limiter can be defeated by setting the
Threshold to the maximum “Off” value.
Attack – The time-‐constant of the speed at which the driver heats   up (in seconds).
Release – The time-‐constant of the speed at which the driver cools   down (expressed as   a multiple of
the Attack time).

Xmax Excursion Limiter

The Excursion Limiter protects the driver against excessive linear movement of the cone and voice-‐
coil which could otherwise cause mechanical damage. Since this   movement (excursion) is   largely
related to the inverse of   the signal frequency, drivers are prone to being damaged by very low
frequencies. This limiter   is progressively more sensitive at   lower   frequencies and, rather   than varying
the gain to provide the limiting action, it   uses a sliding high-‐pass filter to progressively curtail the