APA-4E8 Operator’s Manual
Page 67
ta
x
Appendix II: Program Limiter and Peak Limiter
Your amplifier has two levels of dynamic protection on its outputs — a traditional program
limiter, and a peak limiter.
Program Limiter
High performance digital limiters are provided for each output with control over attack time,
release time and threshold parameters. 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.
There is provision, within the remote software application, to set automatic limiter time
constants. Use this option if you are unsure how to set the time constants manually. XTA
recommend the use of the automatic setting.
In this mode the time constants will be automatically set from the corresponding channel’s
High-Pass filter frequency according to the table below.
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)
