Here are some tips for mastering your songs for SoundCloud upload:
SoundCloud transcodes uploaded audio to 128 kbps MP3 to prepare the audio to stream from the site. If an audio file on SoundCloud is made available for download, the downloaded version will be in the original format.
Uploading an MP3 is redundant since SoundCloud will transcode it anyway, which could in turn introduce more artifacts to audio that’s already compressed. Therefore, the best practice is to upload an uncompressed, 24-bit .WAV file and allow SoundCloud to process it.
Here are some recommended settings when mastering audio for SoundCloud:
Use a True Peak limiter, such as Ozone 6, to ensure that the margin is set to –0.3 dBFS. This is an acceptable threshold to mitigate most of the clipping that occurs during the encoding process. However, depending on the source material, you may find a margin of –0.5, –0.7, –1.0, or –1.5 dBFS sounds better, with less distortion. In these cases, you simply have to perform trial and error, perhaps by uploading several versions and deleting all but the best sounding one.
SoundCloud does not have a feature like Apple’s SoundCheck, so an audio master destined for SoundCloud has more freedom to raise the overall RMS level for competitive loudness. Consider this a practical and aesthetic choice. Make sure to use volume matching, such as the ‘automatically match effective gain’ feature in Ozone, to evaluate loudness increases objectively.
Using a stereo imaging tool, narrow the high end between 5–20%. 128 kbps MP3 is the lowest commonly acceptable audio quality. As such, a lot of information is lost during encoding and an extremely wide mix is more susceptible to noticeable artifacts. Ironically, some pre-emptive narrowing can help avoid perceived loss of energy and width.