Free mono checker
Does your mix work in mono?
Check stereo correlation, width and phase, see what each band loses in mono, and switch between stereo and mono while it plays.
Why check your mix in mono
A lot of music is still heard in mono: phone speakers, many Bluetooth and smart speakers, club systems and some radio. When the left and right channels are summed, parts that are out of phase cancel. A wide synth, a stereo-widened vocal or a bass with a chorus on it can sound great on headphones and then thin out or vanish on a mono speaker.
- Stereo correlation runs from −1 to +1. Above about +0.2 the mix is mono-safe; below 0 parts of it cancel.
- Width is the energy of the side signal (L − R) against the mid (L + R), in dB. 0 dB means the sides are as strong as the centre.
- Mono loss is how much quieter the song gets in mono: 0 dB for identical channels, about −3 dB for unrelated ones.
What to fix
- Wide or out-of-phase lows. Keep the kick and bass in the centre below about 150 Hz. Check stereo bass synths, chorus and wideners on bass.
- Negative correlation. Look for a flipped polarity on one side, a spaced microphone pair or an extreme stereo widener. Switch to Mono while it plays and listen for what drops away.
- Very wide but positive. Usually fine. If the mix sounds thin in mono, bring the lead parts a little more to the centre.
MakeItSoundPro masters every song three ways, Gentle, Balanced and Bold. When needed for club systems, the mastering narrows the low end toward mono below about 100 Hz and keeps the highs mono-safe. To check the loudness too, try the free loudness checker, or read how to master a song.
Questions
Is my song uploaded?
No. Your browser decodes and checks the file on your own device; the song never leaves it. Only if you choose to master it is it uploaded, after you sign in.
What is a good stereo correlation?
Anywhere from about +0.2 to +1 is mono-safe: +1 is mono, and most stereo mixes sit somewhere in between. From 0 to +0.2 the mix is very wide and can sound thinner in mono. Below 0, parts of the left and right channels are in opposite phase and cancel when summed.
Why does my mix lose level in mono?
Mono plays (L + R) / 2 on both sides. Parts that are the same in both channels keep their level, unrelated parts such as stereo reverb drop by about 3 dB, and parts in opposite phase cancel. A loss of 1 to 3 dB is normal for a stereo mix; more, especially in the lows, means something disappears.
Why should the bass be mono?
Club systems often run their subwoofers in mono, many phone and Bluetooth speakers are mono, and on vinyl wide bass makes the needle move up and down and can skip. Bass that is wide or out of phase loses weight on all of them. Keeping the kick and bass near mono below about 150 Hz avoids that.
Does mastering fix mono problems?
Partly. Our mastering engine narrows the low end toward mono below about 100 Hz when needed for club systems and keeps the highs mono-safe. A part that is out of phase in the mix, such as a flipped microphone or an extreme widener, is best fixed in the mix itself.