Adjusting volume for MP3 / AAC – SONNOX : Codec Toolbox

Author: sleepfreaks

Adjust volume for iTunes or Soundcloud upload


When exporting your song, we use a limiter/maximizer as the last step to maximize the sound.
The ceiling level for plugins when exporting to WAV should be set to「-0.1dB」.


However, recently the biggest platform for sharing has been changing to the internet.
When purchasing a song, many of us do so on iTunes or Amazon.

Many of these services use MP3 or AAC codec.

The problem here is when
the ceiling level is set to「-0.1dB」, the song will end up clipping.

Sonnox Codec ToolBox

A plugin that will recognize and prevent this from happening ahead of time is SONNOX’s Codec Toolbox.
You can check the clips that will occur after coding in real time.

Tutorial video

Video key point

Sonnox Codec Toolbox_1_順序

This plugin must be placed last on the master insert.

Sonnox Codec-Toolbox_2_形式の変更

After selecting the exported file type, turn on「Codec」and play the song.
Be sure to check the chorus and other parts with denser sound (loud areas).

Sonnox Codec-Toolbox_3_クリップ反応

It will simulate the type selected, and see if it will clip or not.

Sonnox Codec-Toolbox_4_マスターで確認

If it does clip, you can see how much via the master meter.
In this situation, it is going over「0.4dB」.

Sonnox Codec-Toolbox_5_Ceiling Levelの変更

Lower the limiter/maximizer by the amount the level went over.

You can see the optimal level to export to just by doing this.


In addition, from the「nmr」(noise to make ratio) lamp,
you can see the frequencies that will be changed after turning into the selected file type.

Also, if using Logic and wanting to export to AAC (iTunes),
you can use the plugin shown below.