A signal generator has a filter bank that provides weighted versions of audio signals to speakers. The weights were derived by identifying a first constraint that limits a weight that can be applied to an audio signal to be provided to a first speaker. A characteristic of a second speaker that affects how a user will perceive audio signals output by that speaker relative to audio signals output by the first speaker was also determined. A second constraint was determined based on the determined characteristic and the first constraint. The weights were then determined so as to minimize a difference between an actual balance of each signal that is expected to be heard by a user and a target balance. The signal generator can achieve sweet spot correction and sound stage widening simultaneously. It also achieves a balanced sound stage, particularly when the speakers are asymmetric.