Avalon Acoustics Sentinel - Manual (Page 32)

32
6 Subwoofer Amplifier
Design Principle
The Sentinel subwoofer amplifier provides essential support for the lowest
octaves of the musical spectrum. As a fundamental component of the
Sentinel Reference System, the subwoofer amplifier has been specifically
designed to match the superlative speed and coherence of the Sentinel's
upper frequency response.
The 2400 watt subwoofer amplifier is a push-pull bridged design with fully
balanced circuitry. The amplifier utilizes a massive (2 KVA) toroidal transformer
and a storage capacity totaling over 70000 uF, with 10 high voltage/current
Bi-Polar output devices per channel and discrete high voltage/current
voltage regulation. The amplifier has a built-in electronic crossover that is
tuned specifically to the subwoofer driver array and box alignment. The result
is full-bandwidth low frequency output that has perfect phase coherence
down to 16 Hz.
Room Compensation
Loudspeaker positioning within a room dramatically influences sound
reproduction quality. In particular, the distances to the room boundaries
define a complex system of wave nodes and antinodes that can play havoc
with low frequency response and phase characteristics. For example, the
reflection from each room boundary (floor, side walls, front and rear walls,
and ceiling) creates antinodes when the sound wavelength is about four
times the distance to that boundary. The overall effect of these reflections is
acoustic room loading, more commonly known as "room boom."
The Sentinel subwoofer amplifier has a sophisticated electronic network that
allows for in-room tuning and adjustment that can compensate for this
loading effect. We strongly recommend the application of room treatment
(See Section 7, Maximizing Performance) before attempting any
compensations using the subwoofer amplifier. Once your system and room
have been properly set-up and treated, the following procedure can assist
you in fine-tuning your system.