QSC Audio ISA 500Ti Manual De Usuario

The amplifier can be set for normal Stereo 
mode, Parallel Input mode, or Bridge Mono 
mode. 

Stereo Mode- Each channel remains inde-
pendent, and may be used for two different 
signals. 

Parallel Mode - This setting connects 
both inputs together. One signal feeds both 
channels. Each channel's Gain control and 
speaker connection remain independent. 

Bridge Mode- This setting combines both 
channels of a pair into a single channel 
with twice the output voltage. Use only the 
first channel's input and Gain control. Set 
the second channel's Gain control at mini-
mum. The load must be rated for the higher 
power (or voltage) and is connected as 
shown on pages 6 and 7.

ISA 280, ISA 450, ISA 750 and ISA 1350: 
Use of the Low Frequency Filters is recom-
mended. Use the appropriate switch set-
tings to turn the filter ON or OFF and to 
select the filter frequency. When set to the 
ON position, the channel has a 12dB per 
octave Low Frequency filter to limit subau-
dio cone movement, making more power 
available for the loudspeaker’s rated fre-
quency range. The filter should only be 
turned OFF for driving subwoofers.

ISA 300Ti, ISA 500Ti, and ISA 800Ti: The 
Low Frequency Filters are always active 
and not defeatable. Each channel has a 
12dB per octave Low Frequency filter to 
prevent saturation of the 70V loudspeaker 
transformers. This reduces distortion and 
prevents amplifier overload. The 50 Hz set-
ting usually works well with high quality 
loudspeaker transformers. The 75 Hz set-
ting works well with speech-grade loud-
speakers and transformers.