Low Frequency Filters - QSC SRA 1222 User Manual

SETUP-
Low Frequency Filter

Low Frequency Filters

Unless you already have filtering in the signal path
preceding the amplifier, use the low frequency filter to
protect your speakers from cone overexcursion caused
by frequencies below the speaker's limits. The speaker's
documentation will specify the low frequency limit.
Generally, match the frequency selection to your
speaker's low frequency capability. This improves
speaker performance by limiting subaudio cone move-
ment, making more power available for the speaker's
rated frequency range.
Each channel has its own low frequency filter. Channel
1's low frequency filter is operated by switches 2 and 3.
Channel 2's filter is operated by switches 8 and 9.
FILTER ON: To turn the filter on, slide the switch to the right (Sw.2: Ch.1, Sw.9: Ch.2).
FILTER OFF: To turn the filter off, slide the appropriate switch to the left.
20 HERTZ: To set the filter for a 20 Hz. rolloff, slide the switch to the right (Sw.3: Ch.1, Sw.8: Ch.2).
50 HERTZ: To set the filter for a 50 Hz. rolloff, slide the appropriate switch to the left.
NOTE! The filter on/off switch must be set to the "on" position for the frequency
selection to be active. If the on/off switch is set to the "off" position, no filtering will
take place regardless of the frequency selection.
SRA Series amplifier low
frequency response curves.
Output (dB)
Channel 1's low frequency filter is operated by
switches 2 and 3. Channel 2's filter is operated
by switches 8 and 9.
Frequency (Hertz)
19