An all-pole model of the speech spectral envelope is used to code the sine-wave amplitudes in the Sinusoidal Transform Coder. While line spectral frequencies (LSFs) are currently used to represent this all-pole model, it is shown that a mixture of line spectral frequencies and partial correlation (PARCOR) coefficients can be used to reduce complexity without a loss in quantization efficiency. Objective and subjective measures demonstrate that speech quality is maintained. In addition, the use of split vector quantization is shown to substantially reduce the number of bits needed to code the all-pole model.