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You're in the right place if your Focal speaker is producing an unwanted buzzing, droning, or resonant sound that:

• Only occurs at certain notes or frequencies — but not all the time
• Is most noticeable at moderate to high volume levels
• Appears to come from inside the cabinet rather than from the drivers
• Is present in one speaker but not the other in a matched pair
• Cannot be eliminated by changing the volume, source, or cable

This type of fault is distinct from driver distortion (which is present across all frequencies) or tweeter failure (where high frequencies are absent). Cabinet resonance is a mechanical vibration fault and has a specific diagnosis path.

This article covers the Focal Diablo Utopia Evo, Focal Kanta No.2, and other Focal floorstanding and standmount speakers where cabinet resonance has been reported.

Before you contact us — three checks you can do at home

Check 1: Confirm the resonance is frequency-specific

True cabinet resonance occurs within a specific frequency range — for example, a single octave or even a narrow band of notes. Broad distortion across all frequencies usually indicates a driver fault rather than a cabinet issue.

To test this:

1. Play a sine wave tone sweep through the speaker (many free tone generator apps are available for phones and computers).
2. Sweep slowly from 50Hz up to 500Hz, listening carefully at each frequency.
3. Note the exact frequency or range where the buzzing or resonance is most prominent.
4. Confirm whether the sound disappears completely outside that frequency range.

If the resonance is clearly tied to a specific frequency band — this points strongly to a mechanical/cabinet fault. Note the frequency range when you contact us, as this is valuable diagnostic information.

Check 2: Confirm only one speaker is affected

Play music or tones through each speaker individually by temporarily disconnecting one at a time from your amplifier. If the resonance is only present in one speaker and not the other, the fault is almost certainly in that specific cabinet — not in your amplifier, source, or room acoustics.

Check 3: Check for loose external items

Before assuming the resonance is internal, quickly check that nothing external is causing sympathy vibration:

• Check that the speaker grille (if fitted) is firmly seated with no loose clips
• Check that the speaker's base spikes or feet are all making firm contact with the floor or stand
• Check that no objects on the same surface as the speaker are vibrating in sympathy
• Try temporarily placing the speaker on a folded towel or thick mat and retest

If the resonance persists after these checks, the fault is internal and the speaker needs to be assessed by our team.

What to tell us when you contact us

Cabinet resonance faults can't be repaired in the field — the speaker needs to come to us for internal inspection. When you contact us, the following information helps us assess the fault and determine warranty eligibility before the speaker is collected:

• Your speaker model and serial numbers (both speakers if a pair)
• Your proof of purchase
• The specific frequency range where the resonance is most prominent (from Check 1)
• Whether one or both speakers are affected (from Check 2)
• Whether the resonance appeared suddenly or gradually developed over time
• Whether there has been any physical impact to the speaker (dropping, knocking, moving)
• Photos or a short video demonstrating the fault — even a phone recording is helpful

Contact Westan Support: Email focal.support@westan.com.au or submit a ticket at support.westan.com.au. We aim to respond to all speaker warranty enquiries within 2 business days.

What happens next

Cabinet resonance cannot be reliably diagnosed or repaired without physically opening the cabinet. Once we've reviewed your information, we'll arrange for the speaker to be returned to us for assessment. If the fault is confirmed as a manufacturing defect (loose internal brace, component, or port tube), the repair is covered under Focal's 5-year passive speaker warranty.

If the resonance is found to be the result of physical damage (impact, dropping), it may not be covered under warranty, but we'll always discuss repair options with you before any work is carried out.

Frequently asked questions

My speakers are expensive — do I really need to send them in?

Unfortunately yes — cabinet resonance cannot be accurately diagnosed or fixed without opening the cabinet, and we'd never recommend a customer attempt this themselves on a premium speaker. We take care of your speakers with the same care we'd expect for our own equipment, and we'll pack them securely for return transit.

My warranty claim for cabinet resonance was rejected as accidental damage, but I never dropped the speaker. What can I do?

If you believe the rejection was incorrect, contact us with your technical findings — particularly the frequency measurements from Check 1. Frequency-specific resonance at a consistent pitch, without any evidence of physical impact, is strong evidence of a manufacturing defect rather than accidental damage. We'll review your case.

Is cabinet resonance covered under the 5-year passive speaker warranty?

Yes, if it's confirmed as a manufacturing defect. Focal passive speakers carry a 5-year warranty, and internal mechanical faults that cause resonance are covered within that period. Physical impact damage is not covered.

Both speakers in my pair have started resonating. Does that make it more likely to be a manufacturing issue?

Resonance appearing in both speakers simultaneously, without any physical event, is a strong indicator of a design or batch-related manufacturing issue rather than isolated accidental damage. Please contact us and provide details for both units, including serial numbers.