BSS Audio FCS-966 Owner's Manual - Manual (Page 23)

It is highly undesirable
to send large amounts of
low frequency energy to
speaker systems that are
unable to cope with it.
This leads to distortion and
premature overload. As the
HP filter is steep, it is able
to more effectively remove
this energy than the main
equalizer low frequency
bands. In addition to
cleaning up the sound this may well enable the low frequency controls of
the main equalizer to be used more creatively, as they do not now need to
be employed to deal with sub-bass. Because power absorbing low frequency
content has been removed, it may be possible to turn up the gain beyond the
point that previously resulted in system overload.
One major application for the HP filter is for removing the bass signals from
monitor wedges designed for vocalists. As it may also be required to use one
monitor mix for more than one performer, the HP filter provides a convenient
method of effectively removing inappropriate signals from individual monitor
feeds.
Be aware that making the system ‘flat’ by applying large amounts of boost
is not desirable; when real program is applied to a system setup this way,
overload is almost certain to occur. It is far better to reduce the level of peaks
than try to fill in large holes. Be cautious also of pushing a speaker, particularly
a bass speaker, to reproduce sounds which it is not capable of. This just leads
to extra distortion. The extra heat and cone movement may also permanently
damage the driver.
8.4 Uses for the HP
Filter
Fig 8.2 using the graphic
with RTA