QSC CMXa Série Mode D'emploi page 8

Input Low-Frequency Filter
What it is
The low-frequency (LF) fi lter rolls off signals below either 30 Hz or 50 Hz
This improves bass performance by limiting sub-audio cone motion, making more power available for
the speakers' rated frequency range.
The fi lter settings for each channel are controlled individually through the DIP switch settings shown
in — Figure 6. When the fi lter is turned off
sub-audio inputs.
When to use it (or not)
As a rule, your speakers will sound better with proper
fi ltering. Unless you already have fi ltering in a preceding
device, match the setting to the low frequency rating of
your speakers. Vented (bass refl ex, ported, etc.) speakers
are especially sensitive to cone over-excursion at
frequencies below their rated limit.
EN The 50 Hz fi lter works well with most compact full-range
speakers, and has a slight boost at 100 Hz for greater
fullness. The 30 Hz fi lter is intended for subwoofers and
large full-range cabinets. The "off" position should be used
only for applications such as studio playback monitoring,
where you need to know if there are unwanted sub-audio
signals present in your mix.
(— Figure 8
(— Figure 7), a 5 Hz roll off protects against DC or deep
8
and — Figure 9).
— Figure 7 —
— Figure 8 —
— Figure 9 —
— Figure 6 —