A relationship between the spectrum of a cold jet at 90° and the spectra at arbitrary angles and temperature ratios is explored, by combining limiting forms of analytical solutions of Lilley's equation for the high and low frequency limits. The model extends that presented previously at ICSV13 (2006), and considers the sources as compact. For angles inside the cone of silence, refraction is explicitly included. For the hot jet, it is shown that new components which exist in addition to those contributing to the cold one, can show both dipole and quadrupole efficiency. Predictions are compared to experimental results and it is shown that the model achieves good to reasonable agreement both for cold and hot jets. For the hot jet, at 30°, however, the model over-predicts the spectra. The discrepancies point out to the possible relevance of non-compactness effects. Empirical corrections are proposed to enhance the prediction capability of the model.
