Why can solid metal bracing around a sound attenuator make noise worse?

A sound trap cannot do its job if vibration bypasses it through rigid metal. Separate fan, flex connector, silencer, and supports per the approved acoustic detail.

['A sound attenuator reduces airborne noise, but rigid metal tied from the fan casing across the attenuator can carry vibration right around it.', 'Check whether stiffeners, braces, duct, or hangers are creating a continuous metal path across the acoustic break. The recovery is usually to remove the bridge, restore the flex/vibration break, and keep equipment/supports isolated per detail.']

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