Filter QSC LF-3

QSC LF-3

The LF-3 Low-Frequency filter, when used with the XC-3 two-way crossover, provides the low-frequency crossover to create a three-way active system. The unit mounts to the rear panel of a two-channel DCA or CX amplifiers to save cost and rack space. The output signal andthe operating power for the unit are conducted through the amplifiers DataPort, eliminating added external wiring or power transformers.

The LF-3 features two discrete channels with 4th-order Linkwitz- Riley low-pass filters with 24 dB/octave slopes. Each channel has an all-pass filter providing delay for time alignment of lowfrequency drivers with mid- or high-frequency drivers, as well as a trim control providing 0 to 20 dB of attenuation for matching levels among the various frequency bands. Frequency and delay parameters for both channels are set individually. One LF-3 mounted on an amplifier will support two other amplifiers with XC-3 accessories installed, even in stereo.

Features

Compatible with 2-channel DCA series or CX series amps
Designed for tri-amp cinema or installed sound systems
Adds crossover and time alignment functions without requiring additional rack space, cabling, or AC outlets
Selectable low-pass frequencies from 80 to 500 Hz
Selectable time-alignment delays from 0.3 to 1.8 millisecond
Mounts directly to back of amplifier via DataPort interface
Precision components for accurate performance
Active balanced XLR inputs

Specifications

Low-pass frequency: Selectable using SIP resistor networks: 80, 150, 200, 250, 300, 400 & 500 Hz
Time alignment (all-pass) delay: Selectable using SIP resistor networks: 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 1.0, 1.3, 1.4 & 1.8 miliseconds
Low frequency delay: Bypass or engage using DIP switch
Gain adjustment: Trim potentiometer 020 dB attenuation
Input: Female 3-pin XLR, one per channel
Output to amplifier: Male HD-15 connector to amplifier DataPort
Accessorys operating power: Male HD-15 connector to amplifier DataPort
Input stage type: Electronically balanced differential
Output stage type: 3Balanced
Dynamic range: 118 dB nominal
Total harmonic distortion: Less than 0.1%
Signal to noise ratio: Min. 103 dB
Low-pass filter type: 4th-order Linkwitz-Riley alignment; -6 dB at crossover frequency
Low-pass roll-off type: 24 dB/octave rolloff
Supply Voltage (no load): +15 volts provided by amplifier, -15 volts provided by internal charge-pump converter
Supply Current Requirements: Less than 50 mA
Operating Temperature: 070 degrees Celsius
Input type, each channel: Electronically balanced differential
Input impedance: 22.6 kohm balanced; 11.3 kohm unbalanced