SOLIPSIUMAlpha

SOLIPSIUM Super resolution audio engine

Audiobooks

Clean up audiobook narration.

Drop a chapter here. Solipsium measures its noise, hum and clipping in your browser before anything changes, and the loudness checker reads it against ACX afterwards.

Drop a chapter here

Solipsium checks it in your browser for clipping, hum and noise, without uploading it. It can then repair the first 20 seconds for you to hear, with no account.

WAV, MP3, M4A, MP4 and more, up to five minutes for the check.

Choose a chapter

The numbers

What ACX asks of each file.

ACX, the service that publishes audiobooks to Audible, lists its numbers in its audio submission requirements. The loudness checker reads all three.

  1. RMS between -23 and -18 dB.

    The average level of the chapter. Raising or lowering the whole file moves it.

  2. Peaks no higher than -3 dB.

    The loudest sample. A limiter in your own editor holds it there.

  3. A noise floor no higher than -60 dB.

    The level of the room between sentences. Turning the file up raises it too, so a floor less than 37 dB under the RMS level cannot pass by gain alone: only less noise can.

Fault by fault

What a home booth leaves, and what is repaired.

The try repairs the first 20 seconds on Solipsium's server and lists a reason for each step. The editor, with a free account, repairs the whole chapter.

Room noise.

A steady floor within 26 dB of the voice gets Full-band speech cleanup, a speech model that keeps the voice's full range and lowers what surrounds it. The result reads: “A steady noise floor was found, so it is removed.” A floor further down than 26 dB is not labelled, though ACX can still fail it. A listening model then decides; when it hears damage the cleanup clearly reduces, the result reads: “Nothing was measured wrong, but a listening model heard damage that speech cleanup clearly reduced, so speech cleanup is used.” In the editor you can run Full-band speech cleanup yourself.

Hum from the interface.

A ground loop between a USB interface and a computer puts mains hum into the narration. It is notched out in bands 3 Hz wide: “Mains hum was found, so it is notched out before any cleanup.”

Mouth clicks.

A few clicks do not reach the try's crackle label. In the editor, select the passage and press Clicks, which redraws every short spike it detects. Its note says “in clean audio it can find spikes that are not clicks and change them too, so use it only where you hear clicks.”

Pops on p and b.

In the editor, the pop tool filters a deep thump from a p or b hitting the microphone where it finds one. On October 3 we added made-up pops to 474 versions of 80 recordings: 125 measured better and 2 worse, and the sound around the pops moved further from the original in 424. In 10 of the 80 recordings with no pops added, part of the sound measured worse.

Questions

About audiobook narration.

Will the repair make my files pass ACX?

It does not set ACX's levels. Repair the noise first, set the level in your own editor, then measure the finished file with the loudness checker, which gives a pass or fail for each of ACX's numbers.

Does it add room tone?

No. The repair lowers noise; it never adds any. Record half a minute of your booth's silence if your chapters need room tone between sections.

Can it remove breaths?

The editor's breath tool is meant to lower breaths between words. In an October 5 test, it missed nearly all of the 480 made-up breaths we added to versions of 80 recordings, and in 47 of 313 test recordings it lowered part of a word.

Will cleanup change my voice?

It can. The editor's note on Full-band speech cleanup reads: “Targets hiss in speech. Check quiet or distant voices; may remove music and ambience.” Switch between Original and Repaired on the same words before you keep it.

One chapter or the whole book?

One chapter a project: the editor imports up to 30 minutes and 1 GB at a time. A longer chapter can be cut with the audio splitter.

Is my recording uploaded?

Not for the check, which runs in your browser. Pressing Repair the first 20 seconds sends those 20 seconds; when your browser could not open the file, or it runs over five minutes, the file itself goes to Solipsium's server, so the try is offered for it only up to 25 MB. Solipsium keeps only the first 20 seconds and deletes them within an hour. If you are signed in, a file you drop or choose is uploaded to your account and opens in the editor instead. The privacy notice has the rest.

Free audio tools

Related free tools.

For the numbers and the finished files.

The whole chapter.

Make a free account and drop the same chapter into the editor to repair all of it, up to 30 minutes at a time.

Repair the whole chapter

Free account, no card.