A polymorphic playback system in which one or more parameters of a signal path of the polymorphic playback system are varied based on one or more characteristics of a playback signal processed by the signal path may include a control subsystem configured to detect an out-of-band noise profile of the playback signal and set one or more playback signal magnitude thresholds for switching between polymorphic modes of the polymorphic playback system based on the out-of-band noise profile, wherein the polymorphic modes comprise at least a first polymorphic mode in which one or more first parameters are applied to the signal path and a second polymorphic mode in which one or more second parameters are applied to the signal path.