The 40 Hz Null Looked Terrible. It Wasn't the First Problem to Fix.
Verification pending · Evidence-led diagnosis · Reversible first move · Verification pending
A dedicated listening-room review for a high-capability two-channel system. The owner wanted stronger bass continuity and authority from the Wilsons while protecting image depth, centre lock, vocal scale and stage width. had assembled Wilson Audio Sasha II loudspeakers, Audio Research electronics, Holo Audio May KTE DAC, Roon/HQPlayer playback and Sonore opticalRendu. The SVS subwoofers were deliberately excluded from this first review.. The Right channel showed a deep cancellation near 40 Hz, while the combined Left + Right trace retained a severe loss around 90 Hz.
The System and The Challenge
Context: A dedicated listening-room review for a high-capability two-channel system. The owner wanted stronger bass continuity and authority from the Wilsons while protecting image depth, centre lock, vocal scale and stage width.
System: Wilson Audio Sasha II loudspeakers, Audio Research electronics, Holo Audio May KTE DAC, Roon/HQPlayer playback and Sonore opticalRendu. The SVS subwoofers were deliberately excluded from this first review.
Symptoms: The Right channel showed a deep cancellation near 40 Hz, while the combined Left + Right trace retained a severe loss around 90 Hz.
Room Constraints
- The Wilson-only behaviour had to be understood before adding the subwoofers
- Existing treatment was retained during the first test
- The owner did not want ceiling treatment
- Image depth, centre lock and stage width had to be protected
The Starting Point
The supplied plan showed a substantial L-shaped room with treatment already in place and the loudspeakers well into the room. Available decay evidence did not justify more treatment as the first move.
Investigation & Modelling
The Left speaker substantially filled the isolated Right-channel 40 Hz null when both speakers played, but the combined response did not fill the shared loss around 90 Hz. AudioBro therefore prioritised the stereo weakness rather than the most dramatic single trace. A front-wall boundary interaction remained a leading hypothesis, not a proven cause.
Measured diagnosis plus consultant interpretation. Cause remains provisional until controlled before/after captures.
Recommended First Move
Mark both Sasha II positions, move both speakers six inches closer to the front wall together and repeat Left, Right and Left + Right measurements with every other variable held fixed.
- Mark the current position of both loudspeakers
- Move both speakers six inches closer to the front wall together
- Keep spacing, symmetry, toe-in and listening position unchanged
- Keep level and Roon/HQPlayer configuration unchanged
- Remeasure Left, Right and Left + Right with priority on 70–120 Hz
- Refine in small equal increments only if the combined region improves
No post-change improvement has yet been verified. If the combined region worsens, the marked baseline is restored.
Recommended and reversible. Not yet implemented or verified.
Verification Pending
Measured diagnosis. The cause remains unverified, the recommended test has not been implemented and no improvement is claimed.
Why This Case Matters
The largest-looking problem on a graph is not automatically the first problem to solve. AudioBro connected the measurement to stereo listening, chose one reversible variable and protected the evidence trail.
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