Acoustic performance comes from the complete floor assembly rather than the underlay alone. The subfloor material, slab or timber construction, ceiling below, carpet type, fixing method, room geometry and installation details can all influence impact noise. Dunlop's guidance specifically warns that building information is needed because acoustic results are site-dependent. That is why an underlay test result should be treated as evidence for a tested system, not as a guarantee that every home will achieve exactly the same result.
