Wilson Audio WATCH Dog Subwoofer Series-2 - Manual (Page 21)

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duct panels applied to that part of the wall where the reflection occurs.
Section 3.0 - Resonance
Resonance in listening rooms is generally caused by two sources:
• The structures within the listening room
• The volume of the air itself in the listening room
Structural Resonance
Structural resonances are familiar to most people as buzzes and rattles, but this
type of resonance usually only occurs at extremely high volume levels and is usually
masked by the music. In many wood frame rooms, the most common type of structur-
al resonance problem is “booming” of walls and floors. You can test for these very
easily by tapping the wall with the heel of your hand or stomping on the floor If it is a
wooden floor, this is done to detect the primary spectral center of the resonance. To
give you an idea of what the perfect wall would sound like, imagine rapping your hand
against the side of a mountain. Structural wall resonances generally occur in the low
to mid-bass frequencies and add tonal balance fullness to any system played in that
room. They, too, are more prominent at louder levels, but their contribution to the
sound of the speaker is more progressive. Rattling windows, picture frames, lamp
shades, etc., can generally be silenced with small pieces of caulk or with blocks of
felt. Short of actually adding additional layers of sheet rock or bookshelves to flimsy
walls, there is little that can be done to eliminate wall resonances.
Air Volume Resonance
The volume of air in a room will also resonate at a frequency determined by the
boundary location and size of the room. Larger rooms will resonate at a lower frequen-
cy than will smaller rooms. Air volume resonances, wall panel resonances, and low fre-
quency standing waves combine to form a low frequency coloration in the sound. At
I n Yo u r R o o m - C o n t i n u e d