Compare polarity while controlling your listening position
In Phase sends the same sine wave to both channels. Out of Phase inverts the right channel. Any audible difference depends on how the two physical outputs combine where you listen.
A repeatable check
- Use two speakers, sit centrally, lower volume, and temporarily disable mono or spatial processing.
- At the initial 200 Hz setting, alternate In Phase and Out of Phase without moving or changing volume.
- Stop before changing frequency, then replay both modes. Repeat at a nearby seat to see whether the result depends on position.
What the result suggests
- In Phase sounds fuller than Out of Phase
- This is consistent with the speakers adding more constructively at that position and frequency. It does not establish correct polarity across the whole system.
- Out of Phase repeatedly sounds fuller
- Check the equipment's polarity labels and processing settings. Inspect any speaker wiring with the system powered off; room effects can produce similar results, so do not change wiring based on one tone alone.
What this cannot establish
This is a relative two-channel polarity comparison, not an absolute phase measurement. Headphones do not combine acoustically in the room in the same way, and a mono downmix can cancel the inverted signal.
Frequently Asked Questions
Does a fuller inverted tone prove that a speaker is wired backwards?
No. Speaker distance, room reflections, frequency, and audio processing can change the comparison. Repeat at another position and check the equipment's polarity labels. Power the equipment off before inspecting connections.
Can I use headphones for the same wiring check?
Headphones can demonstrate the change in stereo image, but their two outputs do not combine in a room like loudspeakers. A headphone listening result cannot establish the polarity of your speaker wiring.