Power spectra derived from the velocity fields of three different models, mapped over frequency and radial distance. For easier comparison all the different power spectra have been area normalized. Left: model st29gm04n001, the hottest and smallest model, is shown. Middle: the standard model st28gm06n26 is shown. Right: model st28gm07n001, the coolest and most luminous model with the largest radius, is shown.