can contribute minute amounts of noise) are possible. All of our designs are
exhaustively tested. A subwoofers design isn't complete until all components can
survive a 15 hour test of being driven continuously to maximum output.
Amplification
As in all other current SubSeries subwoofers, these subwoofers utilize a high
efficiency high power class H power amp. Briefly, audio amplifiers are inherently
inefficient because they are designed to have the capability of delivering great
output power yet spend most of their life delivering fairly low power. Their output
devices must deliver current while withstanding the high power supply “rail” voltages
needed for peak outputs. With a Class H design the rail voltages are not constant.
They swing high when the music demands it and stay low during quiet passages.
This is achieved by a sophisticated music modulated high frequency switching
power supply. Power dissipated as heat is greatly reduced and more power is
available per dollar of cost. A second benefit is that they tend to have high peak
power relative to their steady state power. The HD10, for example, has 750 watts
continuous but is capable of over 1000 watt peaks. The result is a subwoofer
capable of the great transients required by dynamic music and explosive sound
effects. The HD8 and 10 offer the latest most efficient implementation of this special
Class H technology.
The HD subwoofer’s heavy passive radiators are mounted in a dual opposing
design to drastically reduce cabinet vibrations. For lowest bass notes, an opposed
force would be exerted by a single passive radiator. This force attempts to move the
cabinet opposite the radiators movement. By mounting the dual passive radiators
on opposing cabinet faces, the reaction forces nullify each other and no energy is
lost due to these forces acting on the cabinet. Residual force from woofer movement
may still impart some vibration to the cabinet. In our early testing we noted that, at
maximum levels, the cabinet would tend to “walk” along the floor. We solved the
problem by designing special compliant feet with enough “give” to absorb cabinet
vibration and keep the HD Subwoofer in one place.
Severe duty aluminum cast baskets, very large magnet structures, and high power
voice coils allow the HD8 and HD10 to effortlessly churn out low frequencies at
foundation shaking levels and to do so for years to come.
Whichever PSB subwoofer you have chosen, we hope that you appreciate the
attention to detail that has gone into its design and, of course, that you enjoy using it.
Please take the time to read the following sections about the placement of your
subwoofer, and its connections and adjustments.
III. Warranty Registration
We recommend you take a few moments now to register your warranty, preferably
on-line at www.psbspeakers.com or via the enclosed registration form so that we will
be able to serve you better in the future.
Unpacking
The packing materials of your PSB HD Subwoofers are designed to protect them
from damage during shipping. Retain the packaging in case the need arises to
transport the speakers in the future.
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