Example techniques may involve controlling a passive radiator. An implementation may include a device buffering successive samples of audio content. For sets of buffered samples, the device predicts excursion of the passive radiator caused by playback of the respective set of buffered samples by active speakers via a model. The device limits excursion of the passive radiator to less than an excursion limit when certain sets of buffered samples are predicted to cause the passive radiator to move beyond the excursion limit. The device plays back the successive samples of the modified audio content via the active speakers. The device measures excursion of the passive radiator when sets of buffered samples are played back via the active speakers. For sets of samples, the device determines respective differences between the predicted excursion and the measured excursion and adjusts the model to offset determined differences between the predicted and measured excursion.