Abstract: An apparatus for homogenizing liquid such as emulsions and dispersions wherein the liquid is jetted from a nozzle onto a blade which is allowed to or cause to vibrate. To each side of the blade is a tuning member such as a plate which is adjustable towards and away from the blade thereby to constrain the passage of the liquid over the blade to the spaces at opposite sides of the blade and between the tuning plates and the blade. The position of the tuning plates depends upon the conditions of or in the liquid such as pressure, temperature and viscosity and the apparatus is set for optimum running depending upon these conditions.