C O M B F I L T E R E Ff E C - WILSON AUDIO Sophia Series 2 Owner's Manual

S S 2 O
O P H I A E R I E S
positioning ASC Tube Traps™ in the corners of the room. Very serious low fre-
quency accentuation usually requires a custom-designed bass trap system.
Low frequency standing waves can be particularly troublesome in rooms
constructed of concrete or brick. This rigid and massive construction method
traps the bass in the room unless it is allowed to leak out of the room through
large window and door areas.
In general, placement of the speaker in a corner will excite the maximal
number of standing waves in a room, and is to be avoided for most direct radiator,
full range loudspeaker systems. Some benefit is achieved by placing the stereo pair
of loudspeakers very slightly asymmetrically in the listening room so that the
standing waves caused by the distance between one speaker and its adjacent walls
and floors are not the same as the standing wave frequencies excited by the dimen-
sions in the other channel.
C o m b F i l t e r E f f e c t
A special type of standing wave, noticeable primarily in the midrange and
lower high frequencies, is the so-called "comb filter effect."
Acoustical comb filtering occurs when sound from a single source, such as a
loudspeaker, is directed toward a microphone or listener at a distance. The first
sound to reach the microphone will be the direct sound, followed by delayed
reflected sound. At certain frequencies cancellation occurs because the reflected
sound lags in phase relative to the direct sound. This cancellation is most apparent
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