Check left and right audio on iPhone
A short SignalProof channel check for stereo headphones and speakers, with setup checks for mono audio, balance and output routing.
Before you start
Keep system volume fixed.
Write down position and conditions.
Start quietly; confirm the output route.
Treat results as practical comparisons.
If the left and right sides seem swapped, one side is quiet, or both sides play the same signal, first check where the sound is actually being sent. A channel check can reveal what you hear on each side. It does not by itself tell you whether the cause is a cable, setting or hardware component.
What you need
Use stereo headphones or a stereo speaker setup connected to your iPhone. No sound meter is required to check direction by listening. SignalProof's left, right and stereo selections refer to the audio channels in the output route.
Confirm the route before testing. A single mono speaker may combine both channels. Bluetooth devices, adapters and speaker processing can alter channel behavior. This check does not individually address a surround system's center or rear speakers, and CarPlay support is not promised.
Run the check
- Connect the stereo device, put it in its normal position, and start with low system volume.
- Open Tests → Check channels in SignalProof 1.1.0, or choose a low-level tone and channel in the generator.
- Play the left channel. Note which side you hear it on. Stop before switching.
- Play the right channel with the same tone and volume. Note the result.
- Check stereo output, then stop playback.
Keep the tone, digital level and system volume fixed. This is a practical direction check; perceived loudness can vary with ear fit and hearing, so use a separate meter and a controlled speaker setup if you need to compare levels.
If both sides play together
Check the iPhone's Mono Audio setting, headphone balance and any mono/downmix mode on the receiving device. Reconnect the output device and confirm the route. Repeat the left and right check after changing one setting.
If the result follows a particular adapter or cable, document that observation. If it follows the headphone or speaker on another source too, that is useful context for support. Keep volume comfortable throughout.
Keep a useful note
Record the output route, cable or adapter, test frequency, digital level, phone volume and what you heard on each side. Repeat the same check after an adjustment.
All signals, channel controls and presets are free in 1.1.0. Lifetime Pro is useful when your work expands to before/after rattle or meter-record comparisons and report sharing; you do not need it for this basic channel check.
For an unusual sound at particular frequencies, read the speaker buzz and retest guide. For comparing speaker readings, read the pink noise guide.