Class-H Amplifier: The PSB HD8 features an efficient, high
power class H amplifier. Class H improves efficiency by using a variable power
supply rail voltage; the voltage only swings high when necessary, using a music
modulated high frequency switching power supply. The available power output is
500 watts continuous, 800 watts dynamic, and 1600 watts dynamic peak.
Woofer: To compliment the powerful amplifier, the HD8 subwoofer
uses an 8" high mass poly-coated fiber cone active driver with a cast aluminum
basket and high density rubber surround.
Passive Radiator Design: The HD8 powered subwoofer incorporates
two opposing 8-inch passive radiators to reinforce the bass output, without taking
up enclosure volume with a port tube. The radiator design is high mass and high
excursion, and the two radiators facing opposite directions reduces cabinet
Volume: The Bass Level control on the back panel adjusts the
volume of the sub.
Low-pass Crossover: The crossover control allows you to adjust
the upper limit of the subwoofer's frequency response. The crossover point is
continuously variable from 50 to 150 Hz and the slope is 24 dB/octave.
Phase Adjustment: A rotary knob on the back of the HD8 allows
you to adjust the phase of the subwoofer's output. The phase is continuously variable
from 0° to 360° for perfect transition from the main speakers to the sub, regardless
Auto Turn-on: When the master power switch is on and a line-level
or speaker-level signal is presented to the sub, the amp will automatically turn on.
The amp turns off automatically approximately one hour after the signal is removed.
LED: The front panel power LED is red when the HD8 is in
standby and changes to green when the amp turns on.
Stereo Preamp Connections (RCA): The line-level input jacks
should be used when connecting the subwoofer to a preamp, integrated amp, signal
processor, line-level crossover, or receiver with stereo preamp outputs. The HD8
also has preamp outputs, useful if your amp has pre-out/main-in jacks.
LFE Connections (RCA): Use the single LFE (Low Frequency
Effects) input when the preamp signal is already crossed over by a surround
processor or line-level crossover. This input bypasses the built-in crossover.
The HD8 also has an LFE output for adding additional subwoofers.
Speaker Level Input: The 5-way binding post speaker-level
input jacks connect directly to the speaker outputs of any amplifier, integrated
amplifier, or receiver. Your amplifier will not notice a significant additional
load when you use these inputs due to their high impedance.
Trigger Input: The sub can be turned on using an external
trigger voltage. Applying an AC or DC (tip positive) voltage of 2-30 volts to
the mono 3.5mm mini-jack will engage the amplifier. The amp turns off automatically
approximately one hour after the voltage is removed.
Power: The rear panel master power switch can be turned off
to defeat the automatic and voltage trigger turn on circuitry.