The best way to soundproof a ceiling follows three main principles:

  1. Improve the mass of the ceiling. The heavier and more dense the ceiling is, the harder it is for sound to pass through it. Use different high density materials, as different materials are better at blocking different sound frequencies. It is the law of diminishing returns if simply using more of the same material
  2. Use high impact clips and bars such as the ReductoClip and Furring Bar System which help to absorb sound energy and vibration. Without this the addition of mass will have very little effect on impact noise
  3. Fill all cavities between joists with acoustic mineral wool. For concrete ceilings use acoustic mineral wool between the concrete ceiling and the first layer of acoustic plasterboard. This will prevent sound resonating and amplifying in this sealed chamber

Learn more: How to soundproof a ceiling