A full practical Guide to design a silent and vibration-free ICE and Electric powered vehicle

A: Pick the wrong stiffness and you ship a car that booms at traffic lights, then comes back as a warranty NVH claim. The isolation target must sit above 1.4× firing frequency, not engine speed, and the rubber rate tolerance belongs in the calculation or production drift will wipe out margin. Option D lands the natural frequency safely below excitation even at rate high-side.

A: Miss this and the car passes bench tests but screams on-road, forcing late-stage bushing swaps. The dominant path is structure-borne; increasing loss factor reduces transmissibility in the mid-frequency band without breaking packaging or durability. The other options either move the problem or worsen force transmission.

A: Do this wrong and weeks vanish correlating noise that never existed in production form. A baseline modal in as-built condition locks down structural dynamics before excitation is added. That sequence lets you separate source from path instead of guessing on public roads.

A: Assume the wrong protection and you under-rate fatigue risk elsewhere in the system. ANC only cancels airborne components at the listener; it does nothing to block force paths through mounts or frames. Treating it as a vibration safeguard breaks DFMEA logic.