Your new DCX amplifier has a TC-XCrossover (Total Control X- over® ) 30Hz-4kHz (see this guide for Crossover Chart).12dB per octave phase correlated crossover built-in to provide superior system flexibility without the added expense and installation of an outboard crossover. The speaker outputs of your amplifier are high pass, low pass, or all-pass according to the HP/LP/FULL switch on the front endplate. You would choose low pass (middle position of switch) to use this amplifier for subwoofers, choose high pass (left position of switch), or full (right position of switch) to use this amplifier for full range speakers.
The RCA outputs are controlled by a separate HP/LP/FULL switch, and are always independent of the speaker output crossover. As well as being able to independently select HP/LP/FULL, your new DCX amplifier allows independent selection of frequencies from 30Hz-4kHz (see Crossover Detent Chart in this guide).
DCX 300.4/600.4/1000.4
Front - 12dB/Octave, Detented High Pass 30Hz-4kHz Rear - 12dB/Octave, Detented High Pass; HP/LP/FULL
RCA Outputs - 12dB/Octave, Detented High Pass; HP/LP/FULL QBASS PLUSTM - on Rear Channel - up to 18dB @ 30, 36, 44, 60Hz
DCX 800.5
Front - 12dB/Octave, Detented High Pass 30Hz-4kHz Rear - 12dB/Octave, Detented High Pass; HP/LP/FULL
RCA Outputs - 12dB/Octave, Detented; HP/LP/FULL Sub-Summed Stereo - 12dB/Octave Detented; 30Hz-4kHz;
HP/LP/FULL
QBASS PLUSTM - on Sub Channel - up to 18dB @ 30, 36, 44, 60Hz
