FBT QUBE SP27 - Manual (Page 30)

Program Limiter and “D-Max” Limiter
The SP27 units have two levels of dynamic protection on its outputs – a traditional program limiter, and a
newly introduced “D-Max” limiter.
High performance digital limiters are provided for each output with control over attack time, release time and
threshold parameters - see page for details. This level of control allows the user to balance the required
subjective quality of the limiter against the driver protection requirements. It does also mean that an
incorrectly set limiter may sound awful! In particular, as with all limiters, using too fast an attack or release time
will result in excessive low frequency distortion. In the
sub-menu there is an option for automatic
limiter time constants. Use this option if you are unsure how to set the time constants manually. It is
recommended the use of the automatic setting.
In this mode the time constants will be automatically set from the High-Pass filter frequency according to the
table below.
The time constants are set by the high pass filter frequency for that channel.
Program Limiter
DesignaCrossover
High Pass Filter Auto Attack Time Release Time
<10Hz – 31Hz 45mS x16 (720mS)
31Hz – 63Hz 16mS x16 (256mS)
63Hz – 125Hz 8mS x16 (128mS)
125Hz – 250Hz 4mS x16 (64mS)
250Hz – 500Hz 2mS x16 (32mS)
500Hz - 1kHz 1mS x16 (16mS)
1kHz – 2kHz 0.5mS x16 (8mS)
2kHz – 32kHz 0.3mS x16 (4mS)
28
ADVANCED AUDIO FEATURES