In the art of audio sound capture, the recording engineer must contend with and balance many sonic issues (external noise bleed, structure-borne resonance, off-axis colorations) in order to arrive at sounds that are truly sonically robust. AuralXpanders give the recording engineer a high degree of control by providing the capability to filter the undesirable external overtones that tend to push the engineer to over-process on the back-end during the mixing stage. AuralXpanders offer the recording engineer a means of tonal control and passive filtering before the sound ever hits the signal path and before ever reaching for a knob or booting-up a plug-in.