WILSON AUDIO Sasha WP, Owner'S Manual

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W i l s o n A u d i o S p e c i a l t i e s
S e c t i o n 1 . 4 – R e s o n a n c e s
as the standing wave frequencies excited by the dimensions in the other channel.
Comb Filter Effect
The “comb filter” effect is a special type of standing wave noticeable primarily at
higher frequencies and shorter wavelengths.
Acoustical comb filtering occurs when sound from a single source, such as a loud-
speaker, is directed toward a microphone or listener from a distance. The first sound
to reach the microphone is the direct sound, followed by a 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 where the two frequen-
cies are 180 degrees out of phase. Further, there is augmentation at other frequencies
where the direct and the reflected sounds arrive in phase. Because it is a function of
wavelength, the comb filter effect will notch out portions of the audio spectrum at lin-
early spaced intervals. Subjectively, comb filter effect evidences itself as follows:
• Added roughness to the sound
• Reduction of harmonic richness
• Smearing of lateral soundstage image focus and placement
Comb filter effects are often caused by side wall reflections. They are best con-
trolled by very careful speaker placement and by the judicious placement of Pinta
Acoustic Sonex® or air duct panels applied to that part of the wall where the reflection
occurs.
Section 1.4 – Resonances
Resonance in listening rooms is generally caused by two sources:
• Structures within the listening room.
• The volume of air itself within the listening room.
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