Problem
Stereo and mono routing differences make one microphone effectively disappear on some playback systems.
Solution
Root Cause / Diagnostic:
A mono microphone plugged into an audio interface is recorded onto a single channel (e.g., Input 1 / Left) of a stereo track without mono downmixing, panning hard left. When mobile viewers listen on devices with summed mono speakers, or when playback platforms collapse stereo channels with polarity inversion, phase cancellation or channel dropping completely mutes the vocal track.
Actionable Fix:
1. In the streaming encoder's audio properties, check the "Mono" downmix checkbox for all single-capsule microphone inputs, forcing the single mono channel to pan center and feed both Left and Right program channels equally.
2. Ensure the microphone input is not wired with an inverted polarity balanced cable; verify that the phase correlation meter on the master output stays firmly between +0.8 and +1.0.
3. Test audio playback on a mobile phone in portrait orientation (mono loudspeaker) and verify that host speech is loud, centered, and fully intelligible.
Pro Tip:
Always insert a goniometer or stereo phase correlation meter on your master broadcast output bus; any correlation values dropping into negative territory (-1.0 to 0) signal destructive phase cancellation on mono consumer devices.
A mono microphone plugged into an audio interface is recorded onto a single channel (e.g., Input 1 / Left) of a stereo track without mono downmixing, panning hard left. When mobile viewers listen on devices with summed mono speakers, or when playback platforms collapse stereo channels with polarity inversion, phase cancellation or channel dropping completely mutes the vocal track.
Actionable Fix:
1. In the streaming encoder's audio properties, check the "Mono" downmix checkbox for all single-capsule microphone inputs, forcing the single mono channel to pan center and feed both Left and Right program channels equally.
2. Ensure the microphone input is not wired with an inverted polarity balanced cable; verify that the phase correlation meter on the master output stays firmly between +0.8 and +1.0.
3. Test audio playback on a mobile phone in portrait orientation (mono loudspeaker) and verify that host speech is loud, centered, and fully intelligible.
Pro Tip:
Always insert a goniometer or stereo phase correlation meter on your master broadcast output bus; any correlation values dropping into negative territory (-1.0 to 0) signal destructive phase cancellation on mono consumer devices.