An apparatus for generating a drive signal for a sound transducer (109) comprises a sound generator (101) which provides an input audio signal. A divider (101) divides the input audio signal into at least a low frequency signal and a high frequency signal and an expander (105) generates an expanded signal by applying a dynamic range expansion to the low frequency signal. A combiner (107) then generates the drive signal by combining the expanded signal and the higher frequency signal. The threshold for applying the dynamic range extension may be adjusted depending on the amplitude of the low frequency signal. The low frequency signal may furthermore be compressed into a narrow frequency band around a resonance frequency. The approach may allow improved audio quality especially from high Q low frequency sound transducers by attenuating decay parts of bass signals thereby reducing sustain or ringing for bass notes.