Not always. This is because SoundCloud applies Loudness Normalization to your tracks as they’re played to listeners.

Mastering tips for SoundCloud

• Target the loudness level of your master at -14 dB integrated LUFS and keep it below -1 dB TP (True Peak) max. This is best for the lossy formats we use (Ogg/Vorbis and AAC) and will ensure no extra distortion is introduced in the transcoding process.

• If your master is louder than -14 dB integrated LUFS, make sure it stays below -2 dB TP (True Peak) max to avoid extra distortion. This is because louder tracks are more susceptible to extra distortion in the transcoding process.