To mono.
The two channels are averaged sample by sample, so what they share keeps its level and what differs between them is softened or cancels.
SOLIPSIUM Super resolution audio engine
Free audio tool
Stereo to mono, mono to stereo, or sound that plays in one ear only.
Fold stereo to mono, copy a mono file to both channels, or give the live channel of a one-sided recording to both ears, in your browser. Each channel's loudest peak is shown first, and you save an MP3 or a WAV.
Drop a recording here
Your browser measures each channel on this device. It stays on your device until you ask for a repair.
MP3, M4A, WAV, FLAC, OGG, Opus and more, up to 30 minutes or 200 MB.
Your channels
| Channel | Loudest peak |
|---|
To mono averages the two channels. To stereo copies the one channel to both sides. One ear to both copies the channel that holds the sound to both sides at its own level, and is offered when one side is silent.
Converted
MP3 files are made with lamejs, a JavaScript port of LAME, under the GNU LGPL. A WAV holds 16-bit samples and is not compressed.
Is the recording itself clear?
Converting the channels does not clean the sound. Solipsium's free try is built for speech: the check below looks at your original file in your browser for background noise, hum, clipping, dropouts and muffled sound, and you can hear the first 20 seconds of a voice recording repaired with no account.
Your first 20 seconds
After signing up, drop the same file into the editor to repair all of it.
What Solipsium hears
Make a free account to repair the whole recording
Then drop the same file into the editor. Scans and short repairs are free.
How it works
Two channels, measured one at a time.
The file is decoded in your browser at 44.1 kHz, the sample rate of a CD, and each channel's loudest sample is measured. A side that stays under -50 dBFS while the other passes -20 dBFS is named silent.
To stereo.
The one channel is copied to both sides. Both sides then hold the same samples, so no width is added.
One ear to both.
The channel that holds the sound is copied to both sides at its own level, and the silent channel is dropped. An average would halve the level instead.
Questions
Before you convert.
Why does my recording play in one ear?
Usually a mono microphone was plugged into a stereo input, so the sound landed on one side and the other recorded nothing. The channel report on this page names the silent side, and One ear to both copies the live one across.
Does mono lose anything?
It loses the difference between the two channels, which is where a sound sits from left to right. A voice recorded in the middle has none, so it comes through as it was.
Does mono to stereo add width?
No. It sounds as it did, in a file with two channels.
Can folding music cancel something?
It can, when a sound is opposite on the two sides. After converting, the page shows the mono file's loudest peak, and says so when the mono file is 6 dB or more quieter than the two channels were.
What about more than two channels?
A 5.1 or quad file is first folded to two channels the way a browser plays it on stereo speakers: 5.1 keeps the centre and the surrounds and drops the low frequency channel. The conversion then runs on those two.
Is my file uploaded?
Not to convert it. Your browser measures and converts the channels on this device, and Solipsium's check of the recording runs in your browser too. Audio is sent only if you press Repair the first 20 seconds. For a mono or stereo recording of up to five minutes, only its first 20 seconds leave this browser; Solipsium repairs them on its server and deletes them within an hour. A longer file would have to go whole, so the try is offered for it only under 25 MB, and Solipsium keeps just its first 20 seconds.
Both ears now, still hard to hear?
The check runs in your browser and lists the background noise, hum and clipping it finds. For a voice recording, you can hear its first 20 seconds repaired.
Check a recording
The check and the 20-second try need no account.