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We often use .mp3. Maybe too often? Mp3 has some benefits over .wav – especially file size. But beside that there are some cons when it comes to audio quality. Sonnox created a tool, which makes these codec problems audible and help you to prevent from bad encoding.

The original .mp3 codec was developed by a team at Fraunhofer Institute. So it’s a logical step, that Sonnox joined forces with the Fraunhofer dudes to create this plugin. It’s easy to use, but gives you a new feeling of how to treat audio, to master it for mp3 or other codecs.

1. Drop the plugin at the master bus and press “IN” button

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2. Choose a Codec and a bitrate to monitor. You can choose between MP3, different AAC versions and iTunes own codec format.

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3. You can insert several codecs at once. To monitor them, click on the loudspeaker button.

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4. Listen and watch the meters. The FFT display at the top shows input and a signal which is discarded by the codec process. You can listen to this signal by clicking “Diff”. Pro-Codec gives you a line with which you can check how audible the difference between your original audio and the encoded audio will be. If it turns red, specific frequency artifacts will be audible.

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This tool has some additional surgical tools, but I don’t want to go too deep. However, there’s one thing which reminds me often that mp3 is not the best choice, even for end users. Clipping. Clipping can occur while the encoding process, as there are samples which aren’t recognized by the codec. Even if the original file did not clip. While monitoring, you can see red lights appearing next to the codec’s name. This indicates that the signal is overloading. To solve this problem, set a trim to compensate this problem.

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After adjusting your file to the proper codec, you might want to export it. The tool gives you the option to do this online and offline. The icon on the lower left opens a stand alone application and opens a manager, which easily does this job for you. And it comes with the nice possibility to safe your files from clipping after being encoded. Another nice feature is that the standalone application can display metadata.

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iZotope added a similar feature to Ozone 7 earlier this year, but it’s not that precise, as you can’t do direct adjustments to the sound or show in-depth analyzing as in Pro-Codec. The included standalone app, which is a station for managing and converting codec files, is a superb tool on top. All in all Sonnox Pro-Codec does great. But when I saw the price … well. £295 … is in my eyes a bit overrated for my personal application. Be sure Fraunhofer get’s a lot for their codec.
But if you have left some bucks and need a high quality mp3 encoder, this one will be the best you can get!