Crossover Filters (High or Low-Pass):
Fully Variable Cutoff Frequency Selection: 50-500 Hz
Detented and Calibrated Potentiometers
Variable Slope: 12dB/oct. Butterworth or 24dB/oct. Linkwitz-Riley
Preamp Outputs
Buffered, pass-through type
Assignable input source on HD600/4 ("front" or "front + rear" summed)
Infrasonic Filter (HD750/1 only)
24dB/oct. at 30 Hz, defeatable.
Helps protect ported subwoofer systems from overexcursion caused by low frequencies below port tuning.
Output Polarity Switch (HD750/1 only)
0 or 180 deg.
Helps quickly tune subwoofer to midbass speaker transition for optimal impact and coherence.
Security Cover for Controls
A cast aluminum alloy security cover is included to keep unauthorized fingers away from your critical system settings.
Remote Level Control
Requires HD-RLC controller (sold separately).
Assignable channels on HD600/4 (rear only or all channels)
Multiple amplifiers can be controlled with one controller by adding standard phone cable splitter (not included).
This is a true level control, not a "bass boost", and can be used as a subwoofer level control or as a full-range volume control, if desired.
Please note that the RBC-1 controller will NOT work with HD amplifiers... you must use the HD-RLC controller.